The clinical problem the researchers tackled is deceptively simple to state but stubbornly difficult to solve. When a woman is diagnosed with invasive breast cancer, determining whether the disease has reached the regional lymph nodes is central to staging, adjuvant therapy planning, and surgical strategy. The current standard for patients whose nodes feel normal and look normal on ultrasound is the sentinel lymph node biopsy, a technique that identifies and removes the first draining node or nodes so they can be examined under the microscope. Yet even this minimally invasive procedure carries real costs: lymphedema, seroma formation, numbness, restricted shoulder mobility, and the anxiety of a second operation when metastases are found. For a substantial fraction of patients, that biopsy ultimately confirms no nodal involvement at all, meaning the procedure was, from a purely diagnostic standpoint, avoidable.

The Madrid cohort comprised 540 consecutive patients with invasive HR+/HER2- breast cancer treated between January 2019 and June 2024, all of whom underwent breast surgery with formal axillary staging. This tumor subtype is the single largest biological category of breast cancer, driven by estrogen or progesterone signaling rather than HER2 amplification, and typically managed with endocrine therapy, chemotherapy in selected cases, and surgery. Because these tumors often behave in a more indolent fashion than triple-negative or HER2-positive disease, the question of which patients can safely forgo parts of the axillary workup is particularly pressing. In this cohort, 173 patients, or 32.0 percent, turned out to have nodal disease despite being classified as clinically node-negative before surgery, a figure that underscores how much microscopic spread evades conventional preoperative assessment.

To build the prediction model, the team assembled a rich set of preoperative variables spanning clinical examination, imaging, and core needle biopsy pathology: tumor size, multifocality or multicentricity, histological type and grade, lymphovascular invasion, perineural invasion, hormone receptor and Ki-67 values, and the findings of axillary ultrasound. Rather than relying on univariate associations, which can be confounded by correlations among variables, the investigators used multivariable logistic regression with LASSO regularization. LASSO, short for least absolute shrinkage and selection operator, is a statistical technique that penalizes model complexity, shrinking weak coefficients toward zero and effectively eliminating predictors that add little independent information. This approach guards against overfitting, the failure mode in which a model memorizes the idiosyncrasies of its development dataset and then performs poorly on new patients.

The variables that survived LASSO selection tell a coherent biological story. By far the strongest predictor was a suspicious axillary ultrasound, which carried an odds ratio of 16.42, meaning patients with abnormal-appearing nodes on imaging had more than a sixteenfold increase in the odds of harboring metastases compared with those whose ultrasound was unremarkable. Lymphovascular invasion on the preoperative biopsy, an indication that tumor cells have already entered lymphatic or blood vessels within the primary tumor, roughly doubled the odds at an odds ratio of 2.61. Each additional millimeter of tumor size increased the odds by about 4 percent, and multifocal or multicentric disease, where multiple tumor foci are present in the breast, raised the odds by 88 percent. Histological grade was retained in the final model for reasons of clinical relevance even though its statistical contribution was more modest.

Performance metrics matter as much as the predictors themselves, and here the nomogram delivered solid numbers. Discrimination, the model’s ability to separate patients who have nodal disease from those who do not, was quantified by the area under the receiver operating characteristic curve, which reached 0.83 with a 95 percent confidence interval of 0.79 to 0.87. In practical terms, an AUC of 0.83 means that if the tool were given one patient with nodal involvement and one without, it would assign the higher risk score to the correct patient roughly 83 percent of the time, a level generally regarded as good for a clinical prediction model built on routine preoperative data. Calibration, which asks whether predicted probabilities match observed frequencies across the risk spectrum, was equally reassuring: the expected-to-observed ratio was 1.002, essentially perfect, and the Brier score, a composite measure combining discrimination and calibration, was 0.135, comfortably below the 0.25 that would correspond to uninformative guessing.

A nomogram translates these regression coefficients into a visual scoring system that clinicians can use at the bedside. Each predictor is assigned a point value on a scale, the points for all variables are summed, and the total maps onto a predicted probability of nodal involvement. The Madrid team went further by calculating diagnostic performance across multiple probability thresholds, reporting positive and negative predictive values at each cut-off. This threshold analysis is what makes the tool actionable rather than merely descriptive: a hospital could, for example, define a low-risk band below which sentinel biopsy might be omitted or deferred, or a high-risk band above which more intensive axillary evaluation or direct discussion of nodal therapy could be considered. The authors explicitly frame the nomogram as a support for individualized risk stratification within the broader movement toward axillary surgical de-escalation.

That de-escalation movement has been reshaping breast surgery for two decades. Following landmark trials such as ACOSOG Z0011, which showed that many women with limited sentinel node metastases who undergo breast-conserving therapy do not benefit from completion axillary lymph node dissection, guidelines have progressively relaxed the requirement for radical nodal surgery in selected patients. More recently, trials of omitting sentinel biopsy altogether in older, low-risk patients have gained traction. The HR+/HER2- subtype is a natural focus for these efforts because modern systemic therapy, including endocrine treatment and CDK4/6 inhibitors for higher-risk disease, exerts systemic control regardless of nodal status, while the prognostic value of detecting a single micrometastasis has become increasingly debatable. A reliable preoperative risk estimate feeds directly into these shared decision-making conversations between surgeon and patient.

The study’s limitations are the ones that typically attend retrospective, single-institution models, and the authors are candid about them. All 540 patients came from one Madrid hospital, raising the possibility that referral patterns, imaging protocols, or pathology practices specific to that center could limit generalizability. The retrospective design means some variables, such as tumor-infiltrating lymphocytes or molecular assays not routinely ordered preoperatively, could not be incorporated. Most importantly, the model has not yet been tested on patients outside its development cohort. External validation, ideally in prospective multicenter cohorts drawn from different health systems, is required before any clinical implementation, and the authors state this requirement explicitly in their conclusions. History is littered with prediction models that performed beautifully in derivation and faded on external testing, which is why the field increasingly demands validation before publication of clinical tools is celebrated.

Even with those caveats, the contribution is timely and practical. Roughly one in three clinically node-negative HR+/HER2- patients in this cohort had occult nodal disease, and the strongest signal, the axillary ultrasound, is already obtained in most modern breast units, meaning the nomogram requires no new tests, no additional cost, and no delay to surgery. If external validation confirms the Madrid results, the tool could help identify the substantial minority of patients whose probability of nodal involvement is so low that even a sentinel procedure might reasonably be omitted, sparing them the attendant risks of lymphedema and nerve injury. Conversely, it could flag patients whose risk justifies a more thorough preoperative discussion about axillary management. In an era when precision oncology is often equated with genomic sequencing, this study is a reminder that careful statistical modeling of everyday clinical variables can still move the needle on surgical care, one calculated probability at a time.

Subject of Research: Development of a preoperative nomogram predicting axillary lymph node involvement in clinically node-negative HR+/HER2- breast cancer

Article Title: A preoperative nomogram to predict axillary lymph node involvement in clinically node-negative HR+/HER2- breast cancer

Article References: Carrillo-Peña, J., Osorio-Silla, I., Mahillo-Fernández, I., Sánchez De Molina-Rampérez, M. L., Escanciano-Escanciano, M., Pastor-Peinado, P., Guadalajara, H., García-Olmo, D., & Villarejo-Campos, P. (2026). A preoperative nomogram to predict axillary lymph node involvement in clinically node-negative HR+/HER2- breast cancer. BMC Cancer. https://doi.org/10.1186/s12885-026-17128-2

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17128-2

Keywords: breast cancer, axillary lymph nodes, nomogram, sentinel lymph node biopsy, HR+/HER2-, surgical de-escalation, lymphovascular invasion, axillary ultrasound, prediction model, LASSO regression, risk stratification, BMC Cancer

The research, conducted by a team at The Christie NHS Foundation Trust in Manchester and published in BMC Cancer, examined 400 patients who underwent wide local excision surgery for head and neck melanoma. The investigators set out to determine how often sentinel lymph nodes fail to show up on preoperative imaging, which patients are most likely to experience this failure, and, crucially, what it means for their long-term outcomes. Their findings, drawn from one of the largest cohorts assembled to address this question, add a striking new dimension to the way clinicians may need to interpret a negative or inconclusive lymphatic map.

The technique at the heart of the study is lymphoscintigraphy, a nuclear medicine imaging method in which a small amount of radioactive tracer is injected near the site of the tumour. The tracer travels along the same lymphatic channels that melanoma cells would use if they were spreading, and a gamma camera captures its journey in real time. Surgeons can then see exactly which lymph node basin receives the drainage, and a complementary technique called SPECT-CT, which fuses functional tracer information with detailed anatomical imaging, sharpens the picture further. In melanoma on the trunk or limbs, this process succeeds in identifying a sentinel node in the vast majority of cases. The head and neck, however, is a notoriously difficult territory: the lymphatic drainage patterns there are more variable, more abbreviated, and less predictable than anywhere else in the body.

That anatomical complexity showed itself clearly in the data. Among the 400 patients reviewed, sentinel lymph node visualisation was absent in 35 patients, a prevalence of 8.8 percent. In other words, nearly one in eleven patients with head and neck melanoma arrived at surgery without any identifiable sentinel node on their preoperative imaging. For a staging procedure whose entire value depends on finding that first draining node, this is a substantial minority, and one that has historically lacked a clear interpretation. Clinicians have long debated whether non-visualisation simply reflects quirky anatomy, technical limitations of the imaging, or something more biologically meaningful about the tumour itself.

The most arresting finding of the study concerns what happened next to those 35 patients. Melanoma recurrence occurred in 11 of them, amounting to 31.4 percent of the non-visualisation group. While the study’s design, as a retrospective cohort, cannot prove that the failed imaging directly caused or predicted recurrence in an individual patient, the sheer scale of that recurrence rate transforms the way a blank lymphoscintigram should be read. A scan that shows no drainage at all is not merely an absence of information; it appears to carry information of its own, and that information points toward heightened risk.

The researchers also uncovered patterns in who was most likely to experience non-visualisation. Age emerged as a powerful factor: patients whose sentinel nodes could not be visualised were significantly older than those whose scans succeeded, with a median age of 76 years compared with 65 years among patients with successful visualisation, a difference that was highly statistically significant. This aligns with a broader biological understanding of how lymphatic systems change over a lifetime. Lymphatic vessels can become less efficient with age, and the tracer that would race through the vessels of a younger patient may move sluggishly or not at all through aged, fibrotic, or attenuated lymphatic channels. Age-related changes in skin and subcutaneous tissue, along with cumulative sun damage in the head and neck region, may compound the effect.

Perhaps the most technically intriguing result concerns the relationship between non-visualisation and the substaging of tumours. Melanomas are classified using the T category system, which reflects tumour thickness and ulceration, and within each T category, the suffix ‘a’ denotes tumours without ulceration while ‘b’ denotes ulcerated tumours. The study found that absent drainage was substage-dependent, occurring more frequently in ‘a’ than ‘b’ substages across all T categories, with an odds ratio of 2.98 and a p-value of 0.011. In practical terms, patients with non-ulcerated tumours were roughly three times more likely to show failed sentinel node visualisation than patients with ulcerated tumours of the same thickness category. This is a counterintuitive result at first glance, since ulceration is itself an adverse prognostic feature, but it suggests that the biological characteristics driving lymphatic tracer uptake are not simply the same as those driving aggressive tumour behaviour, and that the two phenomena can diverge in ways clinicians have not previously appreciated.

The study also found that non-visualisation varied according to the primary anatomical site of the melanoma within the head and neck. This is consistent with the well-documented idiosyncrasies of cranial lymphatics: drainage from the scalp may skip conventional neck basins entirely, lesions of the ear and temple can drain to parotid nodes that sit perilously close to the injection site and may be masked by tracer scatter, and midface lesions can send drainage to multiple, asymmetric basins. The researchers identified melanoma sites using photography as part of their methodology, allowing precise correlation between where the tumour sat and whether the lymphatic map succeeded or failed. For surgeons planning a biopsy, this site-dependent variability underscores that the head and neck cannot be treated as a single homogeneous region when it comes to lymphatic mapping.

What are the implications for practice? Sentinel lymph node biopsy remains a key staging tool in head and neck melanoma, and nothing in this study overturns its central role. But the findings suggest that a preoperative scan showing no visualisation should not be dismissed as a technical inconvenience or an uninformative result. Instead, it may warrant heightened surveillance, a lower threshold for serial imaging follow-up, and careful counselling of the patient about their apparently elevated recurrence risk. The association with older age adds a further layer, since elderly patients already face competing health considerations and may benefit from an honest, data-driven conversation about what a failed map means for their individual situation. The substage dependence, meanwhile, hints that future staging discussions may need to incorporate imaging success or failure as a variable in its own right.

There are, as with all retrospective work, limits to how far the conclusions can be pushed. The study reviewed pre-existing clinical data over seventeen years, and imaging protocols, surgical techniques, and follow-up regimens will have evolved across that span. The 8.8 percent prevalence and the 31.4 percent recurrence figure describe this cohort, and confirmation in independent, prospectively collected datasets would strengthen the case for changing clinical guidelines. Even so, the message that emerges is both simple and potentially consequential: in head and neck melanoma, the lymphatic map that fails to light up is not empty of meaning. It may be one of the quiet signals that a patient’s disease is more dangerous than it appears, and learning to read that silence could help clinicians intervene earlier for the patients who need it most.

Subject of Research: Preoperative sentinel lymph node non-visualisation and recurrence risk in head and neck melanoma

Article Title: Preoperative sentinel lymph node non-visualisation in head and neck melanoma: a 17-year retrospective cohort study

Article References: Chowdhury, M., Gajanan, A., Alothman, A., Kumar, H., Walukiewicz, J., & Gajanan, K. (2026). Preoperative sentinel lymph node non-visualisation in head and neck melanoma: a 17-year retrospective cohort study. BMC Cancer. https://doi.org/10.1186/s12885-026-17053-4

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17053-4

Keywords: melanoma, head and neck cancer, sentinel lymph node biopsy, lymphoscintigraphy, SPECT-CT, cancer staging, lymphatic mapping, melanoma recurrence, tumour ulceration, nuclear medicine, surgical oncology, retrospective cohort study

The patient’s story began in September 2019, when she first noticed a small, mobile mass in her left breast measuring roughly 2 by 1 by 1 centimeters. The lump caused no tenderness, no skin changes, and no nipple discharge, so she initially ignored it. Two months later, at another hospital, mammography and breast color Doppler ultrasound both classified the lesion as Breast Imaging Reporting and Data System category III—a designation implying a probably benign finding with less than a 2 percent risk of malignancy—and recommended routine follow-up. Over the following three months, however, the mass grew dramatically, reaching approximately 4 by 3 by 2 centimeters and occasionally becoming painful. That rapid enlargement prompted her admission to the reporting hospital in March 2020, where physical examination found a smooth, moderately firm, mobile mass without skin ulceration, nipple retraction, or enlarged lymph nodes in the armpits.

The imaging workup revealed a striking contradiction. Mammography at the outside hospital had graded the lesion BI-RADS 3, but repeat ultrasound at the new institution upgraded it to BI-RADS 4A, indicating a small but real suspicion of malignancy of roughly 2 to 10 percent. The ultrasound showed a solid, irregular, lobulated mass at the 11 o’clock position of the left breast, containing strip-like blood flow signals with low-resistance arterial waveforms—a vascular pattern that would later prove telling. Chest computed tomography confirmed a mound-shaped mass in the upper inner quadrant with an unclear boundary on plain scan. Meanwhile, laboratory results were entirely unremarkable: blood counts, liver and kidney function, and coagulation were normal, and the tumor markers CEA, CA 15-3, CA 125, and CA 19-9 all sat comfortably within reference ranges. The team noted that breast angiosarcomas frequently produce negative results on routine malignant tumor markers, rendering these tests of extremely low diagnostic value in such cases.

Reconciling the discordant imaging grades against current standards proved decisive in shaping the diagnostic pathway. According to the fifth edition of the American College of Radiology BI-RADS criteria, the 2024 National Comprehensive Cancer Network breast guidelines, and the 2021 Chinese Society of Breast Surgery fibroadenoma guideline, the combined clinical and imaging picture did not meet formal indications for contrast-enhanced breast MRI, bone scintigraphy, or percutaneous core needle biopsy. Those tools are reserved for high-risk patients, radiologically indeterminate lesions with definite malignant suspicion, or preoperative staging of confirmed cancers—not for discordant low-grade BI-RADS 4A lesions accompanied by benign mammographic findings. The clinicians therefore concluded the lesion was highly suggestive of a benign fibroadenoma and recommended elective surgical resection, a decision that conformed to guidelines but, as they later acknowledged, failed to account specifically for the lesion’s rapid growth.

Surgery took place on March 11, 2020, under general anesthesia, and it was here that the case pivoted. Intraoperative frozen section pathology suggested a spindle cell tumor tending toward a vascular origin, with definitive classification awaiting immunohistochemistry. Because the team had rarely encountered such lesions, and because committing to a radical operation on an uncertain diagnosis carried obvious risks, they consulted the patient’s family and made the unusual decision to temporarily suspend the surgery. Final pathology returned on March 17: the excised nodule, about 3.5 by 2.5 by 1.8 centimeters, was packed with anastomosing slit-like vascular channels infiltrating breast lobules and fat, lined by a single layer of endothelial cells showing mild nuclear atypia and occasional mitoses. Immunohistochemistry showed strong positivity for the endothelial markers CD34, CD31, and FLT-1, along with vimentin and smooth muscle actin, while epithelial markers EMA and broad-spectrum cytokeratins were negative. The Ki-67 proliferation index was 25 percent. The diagnosis was low-grade angiosarcoma.

To be certain, the slides were sent for outside consultation at a higher-level hospital, which returned on March 20 with a confirmatory and slightly more concerning picture: part of the tumor showed the mild, well-formed vascular pattern, but other areas were solid, densely cellular, and pleomorphic with mitotic figures, extensive hemorrhage, and necrosis. The consultants recommended optional molecular testing for c-Myc, KDR, and VEGFR2—markers mainly useful for distinguishing primary from radiation-associated secondary angiosarcoma—though the team ultimately judged these unnecessary given the clear histopathological diagnosis. After a hospital-wide multidisciplinary team discussion, the patient underwent completion resection of the remaining left breast tissue plus sentinel lymph node biopsy on March 23. Frozen section confirmed an R0 resection with clear microscopic margins and no sentinel node metastasis, and final pathology found no residual cancer in the surrounding breast, nipple, skin, or basal margin, with zero of three sentinel nodes involved.

The staging and treatment decisions reflected the peculiar biology of this tumor. Under the eighth edition of the AJCC staging system, the disease was classified as stage I (T1N0M0). Unlike conventional breast carcinoma, which spreads chiefly through lymphatic channels, primary breast angiosarcoma metastasizes predominantly through the bloodstream, seeding the liver, lungs, bone, and brain early, while regional lymph node involvement is extremely rare. Routine axillary lymph node dissection is therefore not recommended, and the team performed only a sentinel node biopsy for accurate staging, sparing the patient unnecessary surgical trauma. Beginning April 3, 2020, she received eight cycles of adjuvant chemotherapy—four of doxorubicin plus cyclophosphamide followed by four of paclitaxel—completed without significant adverse reactions by the end of July 2020.

The prognosis data assembled in the report underscore why vigilance matters. Secondary angiosarcoma of the breast, which typically arises after radiotherapy for breast cancer or in the setting of chronic lymphedema known as Stewart-Treves syndrome, carries a five-year overall survival of roughly 38 percent with a recurrence-free survival of about 43 months. Primary breast angiosarcoma fares somewhat better, with a five-year overall survival near 49 percent and recurrence-free survival of about 44 months, with outcomes tied to stage, histological grade, and tumor size. Diagnosis remains the hardest part: mammography yields false negatives in roughly a third of patients because of dense glandular tissue, ultrasound lacks specificity despite showing heterogeneous masses and increased blood flow, and MRI—considered the most useful non-invasive modality—reveals heterogeneous signals and avid contrast enhancement reflecting the tumor’s rich vascularity. Core needle biopsy, the usual route to preoperative diagnosis, frequently returns false negatives because of bleeding risk and marked tumor heterogeneity, meaning most cases are only confirmed after surgery.

Emerging evidence is beginning to reshape treatment thinking for this orphan disease. A meta-analysis by Skarentzos and colleagues found that adjuvant chemotherapy significantly improved survival in primary breast angiosarcoma, with a hazard ratio of 0.11, while radiotherapy showed no survival benefit. Anthracycline-, ifosfamide-, and paclitaxel-containing regimens are considered the most effective, though the disease’s rarity means evidence rests on small series and case reports rather than large trials. Genomic research is opening new doors: the Angiosarcoma Project, a patient-partnered genomic study, has suggested that inhibitors of the phosphatidylinositol-3-kinase catalytic alpha subunit could become targeted therapeutic options, and next-generation sequencing may eventually identify actionable alterations in tumors like this one.

Follow-up tells the story’s encouraging end. The patient was re-examined at one, three, and six months after surgery, then roughly every six months, with breast ultrasound, chest CT, abdominal and urinary tract ultrasound, blood counts, and tumor markers. As of November 5, 2025—more than five years after her diagnosis—she showed no sign of local recurrence or distant metastasis. The authors argue their case carries three broader lessons: that a rapidly growing, benign-appearing breast mass in a postmenopausal woman deserves heightened suspicion even when guidelines do not mandate advanced imaging; that suspending surgery when frozen section reveals something unexpected can preserve diagnostic accuracy and prevent undertreatment; and that multidisciplinary collaboration, staged surgery, and guideline-conformant individualized therapy can deliver excellent long-term outcomes even in a cancer this rare and this easy to miss.

Subject of Research: Primary breast angiosarcoma diagnosis and treatment in a postmenopausal woman

Article Title: Primary Mammary Angiosarcoma in a Postmenopausal Woman: A Case Report

Article References: Liu, T., Xu, Y., Wang, Q., Yu, S., Lin, H., Ye, Z., Zheng, Z., Yang, C., & Hong, T. (2026). Primary Mammary Angiosarcoma in a Postmenopausal Woman: A Case Report. Cancer Reports, 9(9), Article e70653. https://doi.org/10.1002/cnr2.70653

Image Credits: AI Generated

DOI: 10.1002/cnr2.70653

Keywords: breast angiosarcoma, primary breast angiosarcoma, postmenopausal, BI-RADS, fibroadenoma, frozen section pathology, immunohistochemistry, CD31, sentinel lymph node biopsy, adjuvant chemotherapy, R0 resection, rare cancer

A retrospective study published in Breast Cancer Research and Treatment followed 284 women with node-positive breast cancer who received neoadjuvant chemotherapy, the chemotherapy administered before surgery with the goal of shrinking tumors and, in some patients, eradicating nodal disease entirely. The analysis, conducted by a team at the University of Pittsburgh led by Callie Hlavin and Emilia J. Diego, compared patients who underwent full axillary lymph node dissection with those who received targeted axillary dissection, a deliberately limited procedure that removes only the previously involved, marked lymph node along with nearby sentinel nodes. With a median follow-up of 36.3 months, the researchers found no meaningful difference in recurrence, mortality, disease-free survival, or overall survival between the two operations in either of the clinical groups they examined.

The study exploited a technical innovation that has reshaped how surgeons think about the axilla after neoadjuvant chemotherapy. Before treatment begins, the biopsy-proven cancerous lymph node is marked — in this study, with a radioactive iodine seed — so that the same node can be identified and removed after chemotherapy, even if the tumor inside it has completely disappeared. This approach, known as targeted axillary dissection or TAD, allows surgeons to re-examine the very node that harbored cancer at diagnosis, dramatically reducing the false-negative rate compared with sentinel lymph node biopsy alone. After surgery, patients are divided into two groups based on what pathologists find in that recovered node: those with a complete pathologic response, meaning the diseased node shows no residual cancer, and those with persistent disease.

Of the 284 patients, 128 achieved a complete pathologic response in the marked node, designated dSLN-negative. Only 13 of these women went on to receive a full axillary dissection, while 115 — roughly 90 percent — were managed with targeted axillary dissection alone. The remaining 156 patients still had cancer in the marked node after chemotherapy, designated dSLN-positive; 107 of them underwent full axillary lymph node dissection and 49 received targeted dissection. This distribution reflects an evolving practice pattern in which surgeons increasingly feel comfortable omitting the full dissection when the marked node shows eradication of disease, and the Pittsburgh data now provide some of the most direct evidence yet that this comfort is justified.

The survival figures are striking for their equivalence. Among patients with a complete response in the marked node, mortality was 15.4 percent after full axillary dissection versus 8.9 percent after targeted dissection, a difference that did not approach statistical significance. Disease-free survival averaged 19.6 months in the dissection group and 30.7 months in the targeted group, and overall survival was 49.3 versus 45.8 months — again, without significant differences. Among patients with persistent disease in the marked node, mortality was 9.3 percent with targeted surgery versus 10.2 percent with full dissection, disease-free survival was 30 versus 37 months, and overall survival was nearly identical at 36.4 versus 36.2 months. Across every measure the investigators tracked — frequency of recurrence, location of recurrence, death, disease-free survival, and overall survival — the extent of axillary surgery made no difference.

One nuance deserves attention. In the group with persistent nodal disease, the researchers observed a higher frequency of recurrence among patients who underwent full axillary lymph node dissection compared with those who had targeted dissection. That finding runs counter to the traditional assumption that removing more nodes always confers better local control, though the investigators caution that it did not translate into any difference in disease-free or overall survival, and the retrospective design and modest subgroup sizes limit how much weight the observation can bear. What it does underscore is the central paradox that has driven the de-escalation movement: decades of trials have shown that additional axillary surgery does not reliably improve survival, even when it changes local recurrence patterns.

The scientific rationale for trimming axillary surgery rests on biology as much as surgical outcomes. Neoadjuvant chemotherapy can completely eradicate nodal metastases in a substantial fraction of node-positive patients, and that pathologic response is among the most powerful prognostic markers in breast cancer. Systemic therapy circulating throughout the body treats microscopic disease wherever it resides, while regional nodal surgery mainly serves staging and local control. Landmark trials such as ACOSOG Z0011 demonstrated that omitting full dissection in selected sentinel-node-positive patients did not compromise survival, and studies including ACOSOG Z1071, SENTINA, and SN FNAC established that sentinel node biopsy after neoadjuvant chemotherapy is technically feasible — provided the previously positive node itself is identified and removed, which is precisely what radioactive seed marking and targeted dissection accomplish.

The stakes of this debate are far from academic. Axillary lymph node dissection removes a large volume of lymphatic tissue and is a leading cause of lymphedema, the chronic, sometimes disabling swelling of the arm that can follow breast cancer treatment. It is also associated with shoulder stiffness and reduced range of motion, numbness, pain syndromes, infection, and longer operative times and hospital stays. Prospective studies following patients for years after surgery have documented persistent deficits in shoulder strength and function in women who undergo the full dissection compared with those who receive sentinel biopsy alone. If equivalent survival can be achieved without those complications, the argument for routine full dissection in chemotherapy responders weakens considerably — and the Pittsburgh data suggest that even some patients with residual disease in the marked node may fare just as well with less surgery when combined with appropriate radiation and systemic therapy.

The findings arrive amid an active international effort to define exactly how far axillary de-escalation can safely go. Ongoing randomized trials, including TAXIS and the AXSANA study, are comparing less invasive nodal procedures with standard approaches in patients whose disease converts from node-positive to node-negative after chemotherapy. Practice guidelines, including those from the National Comprehensive Cancer Network, have gradually incorporated the option of omitting full dissection for selected patients with a complete response, and surveys of breast surgeons show rapidly shifting practice patterns. The present study adds real-world evidence to this landscape: in a consecutive cohort treated at a single academic center, the extent of axillary surgery simply did not determine who recurred, who survived, or how long they lived free of disease.

Important limitations temper the conclusions. The analysis was retrospective and single-institution, meaning treatment decisions were not randomized and selection bias may have influenced which patients received which operation — indeed, patients with persistent disease were far more likely to undergo full dissection, likely reflecting surgeon and patient preference for maximal treatment. The follow-up of just over three years is meaningful but not definitive for breast cancer, whose recurrences can appear a decade or more after diagnosis, and the small numbers of full dissections among patients with complete response limit statistical power. Nevertheless, the consistency of the results across both patient groups, and their alignment with randomized trial evidence accumulated over the past two decades, makes a compelling case. For the growing number of women whose lymph node disease melts away with preoperative chemotherapy, the message is increasingly clear: the most extensive operation is not the one that saves lives, and a carefully targeted, node-by-node approach may offer the same survival with a fraction of the harm.

Subject of Research: Comparison of targeted axillary dissection versus axillary lymph node dissection for survival outcomes in node-positive breast cancer patients receiving neoadjuvant chemotherapy

Article Title: Equivalent survival in targeted axillary dissection compared to axillary lymph node dissection in patients with node positive breast cancer receiving neoadjuvant chemotherapy

Article References: Hlavin, C., Balogun, Z., Lavage, D. R., Cowher, M. S., Lupinacci, K., Sabih, Q., Soran, A., Steiman, J. G., McAuliffe, P. F., & Diego, E. J. (2026). Equivalent survival in targeted axillary dissection compared to axillary lymph node dissection in patients with node positive breast cancer receiving neoadjuvant chemotherapy. Breast Cancer Research and Treatment, 219(3), Article 18. https://doi.org/10.1007/s10549-026-08078-1

Image Credits: AI Generated

DOI: 10.1007/s10549-026-08078-1

Keywords: breast cancer, neoadjuvant chemotherapy, targeted axillary dissection, axillary lymph node dissection, sentinel lymph node biopsy, axillary de-escalation, lymphedema, disease-free survival, overall survival, pathologic complete response, radioactive seed localization, surgical oncology

The research, conducted at Hospital Canselor Tuanku Muhriz of Universiti Kebangsaan Malaysia and published in BMC Cancer, examined 241 women with clinically node-negative early breast cancer, all staged cT1–2N0M0, who underwent sentinel lymph node biopsy between January 2018 and December 2025. The team, led by surgeon Hadija Mustamin together with pathologists and community health researchers, asked a deceptively simple question: does the density of tumour-infiltrating lymphocytes, or TILs, in the tumour stroma correlate with whether cancer cells are found in the sentinel node?

The findings were striking. Among the cohort, 67 patients — 27.8 percent — had metastasis to the sentinel lymph node. But the distribution of that risk was far from even. When pathologists graded stromal TIL levels according to the internationally accepted 2014 guidelines of the International TILs Working Group, they found that two-thirds of the patients fell into the low-TIL category, 17.4 percent into the intermediate category, and 16.6 percent into the high category. Critically, the highest proportion of nodal metastasis occurred in the group with the fewest infiltrating lymphocytes, a statistically significant association with a p value of 0.023.

To understand why this matters, one must appreciate what TILs actually represent. Tumour-infiltrating lymphocytes are immune cells — predominantly T cells — that have migrated from the bloodstream into the tumour microenvironment, a biological indication that the host immune system has recognised the malignancy and mounted a response. In recent years, TIL assessment has graduated from a curiosity of tumour immunology to a practical, reproducible pathology metric. In triple-negative and HER2-positive breast cancers, high TIL counts are already associated with better responses to neoadjuvant chemotherapy and improved survival. What this new study adds is a potential role in the preoperative and perioperative decision-making around the axilla.

The statistical backbone of the study was a two-stage logistic regression strategy. The researchers first screened clinicopathological variables — tumour size, histological type, grade, lymphovascular invasion, hormone receptor status and TIL category — using univariable analyses, and then entered any variable with a p value below 0.25 into a multivariable model. After adjustment, two factors emerged as independent predictors of sentinel node involvement. Higher TIL levels were associated with lower odds of metastasis, with an adjusted odds ratio of 0.977 per unit increase (95 percent confidence interval 0.961–0.994; p = 0.007). Lymphovascular invasion, the histological evidence of tumour cells invading blood or lymphatic vessels, was independently associated with nodal spread, carrying an adjusted odds ratio of 0.290 (95 percent CI 0.156–0.537; p < 0.001), meaning its presence substantially raised the odds of metastasis.

Interestingly, tumour size — long regarded as a cornerstone of nodal risk prediction — was associated with sentinel lymph node metastasis in the univariable analysis but lost its significance once other factors were accounted for. That statistical humility is itself informative: it suggests that within this cohort of small, clinically node-negative tumours, the biology of the tumour microenvironment and the presence of lymphovascular invasion may carry more predictive weight than size alone. If validated, such a shift could change how pathologists’ reports are weighted in surgical planning.

The clinical implications are potentially significant. Sentinel lymph node biopsy, while far less morbid than full axillary dissection, still carries risks of lymphoedema, seroma, nerve injury and infection. A reliable, cheap, microscope-based biomarker that stratifies nodal risk before surgery could, in principle, help identify patients in whom biopsy yields the greatest information, or in the longer term, support more selective approaches to axillary staging. Because TIL scoring requires only routine haematoxylin and eosin slides and a trained pathologist, it is vastly more accessible than genomic assays or advanced imaging, an especially important consideration in resource-constrained health systems such as much of Southeast Asia.

The authors are careful, and appropriately so, about the limits of their work. This was a single-centre, cross-sectional study, which captures association but cannot establish that low TIL levels cause nodal spread. Only a single pathologist scored the slides, raising questions about inter-observer reproducibility that multi-reader studies would need to resolve. The cohort spans tumours of all molecular subtypes, and TIL biology differs markedly between triple-negative, HER2-positive and luminal cancers; subtype-specific analyses in larger, prospective cohorts with external validation will be required before TIL assessment can be folded into clinically useful prediction models for nodal status. The study received no external funding, and the analysis reflects institutional records from one Malaysian tertiary centre.

Nevertheless, the study joins a rapidly expanding body of evidence that the immune microenvironment is not merely a bystander in cancer progression but an active determinant of how tumours behave. A tumour bristling with lymphocytes appears, in this data, to be a tumour less likely to have seeded the regional nodes — a biological narrative that makes intuitive sense, since a robust local immune response may constrain the earliest steps of dissemination. Conversely, an immunologically cold tumour, walled off from immune attack, may enjoy freer rein to invade lymphatic channels and establish footholds downstream.

For patients, the message is not one of immediate change in care — no guideline today spares anyone a sentinel node biopsy on the basis of TIL counts. But it is another step toward a future in which the pathology report of a breast cancer describes not just what the tumour is, but what the body is doing about it. As immunotherapy reshapes oncology and immune biomarkers move from research benches to clinical reports, studies like this one map the terrain where tumour immunology and surgical decision-making converge. Whether the quiet presence of lymphocytes in a tumour’s stroma can one day spare a woman an unnecessary procedure remains to be proven, but this Malaysian cohort offers a compelling early signal that the immune system has been keeping records all along — records pathologists are only now learning to read.

Subject of Research: Association between stromal tumour-infiltrating lymphocyte levels and sentinel lymph node metastasis in early breast cancer

Article Title: Tumour-infiltrating lymphocytes are associated with sentinel lymph node metastasis in early breast cancer: a cross-sectional study

Article References: Tumour-infiltrating lymphocytes are associated with sentinel lymph node metastasis in early breast cancer: a cross-sectional study. (n.d.). https://doi.org/10.1186/s12885-026-17012-z

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17012-z

Keywords: breast cancer, tumour-infiltrating lymphocytes, sentinel lymph node metastasis, tumour immune microenvironment, lymphovascular invasion, sentinel lymph node biopsy, cancer metastasis, tumour immunology, early breast cancer, pathology biomarker, logistic regression, BMC Cancer

The core of the argument rests on three epidemiological realities. First, roughly half of all canine mammary tumors are benign, meaning that any staging protocol applied indiscriminately before a diagnosis of malignancy is confirmed will expose a large share of patients to unnecessary testing. Second, a clinically relevant proportion of malignant mammary tumors are low grade and highly unlikely to metastasize, so even among dogs with cancer, many derive little benefit from systemic imaging. Third, and perhaps most strikingly, distant metastasis at the time of initial presentation appears to be genuinely rare. In data drawn from the PennVet Shelter Canine Mammary Tumor Program, only 13 of 249 dogs screened for enrollment had detectable distant metastasis, and the median tumor size in that subgroup was 6.7 centimeters, suggesting that metastasis at staging is largely a phenomenon of advanced local disease.

Despite these numbers, recent recommendations have shifted toward more elaborate pre-surgical workups, including thoracic computed tomography, abdominal ultrasound, and sentinel lymph node mapping. The authors contend that this trend is driven partly by the availability of more sensitive imaging technology and partly by a fear of missing occult metastatic lesions, a fear that has not been critically examined against actual detection rates. The consequences are not trivial. Advanced imaging adds substantial cost, requires additional anesthesia or heavy sedation, and delays definitive surgical treatment. In some cases, the accumulated expense of staging may prevent owners from pursuing the surgery that would actually cure their dog, a paradox the authors describe as directly contrary to the goal of cancer care.

To build their case, the researchers looked closely at how human breast cancer, long the conceptual model for canine mammary tumor management, handles the same question. Human breast cancer staging begins with mammography and biopsy, and only after malignancy is confirmed do clinicians proceed to sentinel lymph node biopsy, molecular typing, and, selectively, systemic imaging. Notably, guidelines from the National Comprehensive Cancer Network have evolved over the past decade in the opposite direction from veterinary practice: women with early-stage, low-risk disease based on receptor profile and sentinel lymph node status now forgo systemic imaging altogether. The rationale is that metastasis is rare in early-stage asymptomatic patients, and false-positive imaging findings automatically trigger cascades of additional diagnostics, cost, and anxiety. The canine situation, the authors argue, shares these same mathematical and psychological dynamics, yet veterinary recommendations have moved toward more testing rather than less.

Sentinel lymph node biopsy receives particularly detailed scrutiny. In human breast cancer, the technique replaced radical axillary dissection because it accurately identifies the first lymph node to receive drainage from the tumor with far less morbidity. In dogs, the anatomy is simpler: the axillary lymphocenter typically contains only one or two nodes, and the predictable drainage pattern sends the two cranial mammary glands to the axillary node and the two caudal glands to the superficial inguinal node, with the third gland draining in either direction. Reviews of lymphographic studies show that this normal pattern persists as the predominant route in most dogs with tumors, with deviations being rare and possibly linked to high tumor grade, which promotes lymphangiogenesis, inflammation, and vascular remodeling within the tumor microenvironment.

Yet the authors identify practical obstacles that make routine sentinel node biopsy in dogs problematic. Dogs commonly present with multiple independent mammary tumors, with studies reporting that 60 to 70 percent have tumors in different glands, each with its own histology and biological behavior. The largest tumor is often, but not always, the most aggressive, so selecting a single tumor for mapping risks sampling the wrong lesion, while injecting multiple tumors yields multiple biopsied nodes and larger, more painful surgeries with higher complication rates. Furthermore, because sentinel node techniques require peritumoral or subareolar contrast injection before complete resection, dogs without a confirmed diagnosis of malignancy are routinely subjected to the procedure even when their tumors turn out to be benign or low risk. The authors also note that in dogs, unlike in women, lymph node status has weak implications for chemotherapy decisions, since dogs with high-grade tumors are likely to receive systemic therapy regardless of nodal findings, making the procedure’s main human indication largely moot.

Thoracic imaging comes under similar examination. Three-view thoracic radiographs remain a reasonably sensitive, widely available, and cost-effective method that can be performed under light sedation. Computed tomography detects more small pulmonary nodules, but the clinical significance of that sensitivity is questionable in this population. In human early-stage breast cancer, the false-positive rate for chest CT, about 10 percent, actually exceeded the overall yield of metastasis detection, roughly 2 percent, a cautionary statistic for anyone considering withholding surgery based on small CT findings. Classic necropsy work by Fidler and Brodey established that pulmonary metastasis was present in 81 percent of dogs with metastatic disease, compared with only 5 to 16 percent for abdominal organs, meaning the lungs are the primary metastatic site and abdominal spread is unlikely when thoracic imaging is negative. The authors’ own prospective trial data found that every dog later confirmed at necropsy to have pulmonary metastasis had preceding three-view radiographs documenting it.

Abdominal ultrasound fares similarly in the analysis. Because the lungs dominate the metastatic pattern, the risk of metastasis confined to abdominal organs in the face of negative thoracic radiographs is low. Ultrasound also cannot reliably distinguish benign from malignant hepatic or splenic nodules, generating false positives that invite further invasive diagnostics. A large prospective screening study in healthy middle-aged and older dogs found that physical examination plus cytology of superficial masses detected the great majority of cancers, undercutting the argument that abdominal imaging is needed to catch unrelated occult tumors. Follow-up data from the authors’ earlier cohort showed that non-mammary tumors detected during monitoring emerged a median of 500 to 600 days after the original surgery, indicating they were new developments rather than lesions that staging had missed.

Fine needle aspiration of the tumors themselves is likewise judged unreliable as a screening tool. Reported sensitivity for distinguishing benign from malignant mammary lesions ranges from 25 to 95.2 percent across studies, and even modern cytological grading systems show poor concordance with histology for low-grade tumors, precisely the category where misclassification matters most for staging decisions. Because cytologists evaluate cellular atypia without the architectural context available to surgical pathologists, and because even pathologists disagree about the benign-malignant boundary in low-grade lesions across institutions and countries, the authors decline to recommend routine cytology as a gatekeeper for staging. They do concede it retains value for identifying non-mammary masses such as lipomas or mast cell tumors.

The alternative framework the authors propose is elegantly simple: let tumor size and clinical risk factors decide. For tumors under 1 centimeter, or under 3 centimeters in WHO T1 category, no pre-surgical staging is recommended; post-operative thoracic radiographs are applied by grade, skipped for grade 1, optional for grade 2, and recommended for grade 3. Tumors larger than 3 centimeters warrant pre-surgical three-view thoracic radiographs, as do any tumors with cytologically positive local nodes or obvious malignant features such as rapid growth, ulceration, or deep fixation. Routine fine needle aspiration of palpably normal regional nodes is deemed unnecessary for small tumors, since inguinal nodes are typically removed anyway with the fifth gland, but firm or enlarged nodes should always be aspirated before surgery to adjust the operative plan. Patent blue dye is endorsed for identifying axillary nodes during removal of larger cranial tumors. Abdominal ultrasound is reserved for dogs with positive inguinal nodes, to assess iliac chains, and thoracic CT is judged not indicated in most cases. The authors acknowledge that a small number of small tumors with metastatic nodes could slip through the pre-surgical net, but argue that post-operative grade assessment catches grade 2 and 3 cases. Their closing message extends beyond mammary tumors: staging recommendations across veterinary oncology should be judged by whether results change prognosis or treatment, because diagnostic intensity that offers minimal clinical benefit while imposing financial and emotional costs may ultimately harm the very patients it aims to protect.

Subject of Research: Evidence-based revision of pre- and post-surgical staging practices for canine mammary tumors

Article Title: Considerations for revised staging practices in canine mammary tumors

Article References: Sorenmo, K. U., Cofone, M. A., Donnelly, L., Duda, L., & Stefanovski, D. (2026). Considerations for revised staging practices in canine mammary tumors. Veterinary Oncology, 3(1), Article 9. https://doi.org/10.1186/s44356-026-00061-8

Image Credits: AI Generated

DOI: 10.1186/s44356-026-00061-8

Keywords: canine mammary tumors, cancer staging, veterinary oncology, sentinel lymph node biopsy, thoracic radiographs, thoracic CT, abdominal ultrasound, fine needle aspiration, tumor grade, metastasis, risk-based staging, dog health