The scale of the problem is considerable. Every year, roughly 730,000 new cases of rectal cancer are diagnosed around the globe, making it one of the most common malignancies affecting the digestive tract. For most of modern surgical history, the standard of care has involved radical resection, in which surgeons remove the tumor together with a margin of healthy tissue and the surrounding lymph nodes. The procedure is genuinely effective at curing the cancer, but the anatomical cost is high. The rectum plays a central role in continence and bowel function, and its removal or reconstruction can permanently alter how a person lives. For some patients, particularly those whose tumors sit low in the rectum close to the anal sphincter, a permanent colostomy is an unavoidable consequence.

Professor Toni Seppälä of Tampere University and Tampere University Hospital frames the clinical challenge in terms of a dual mandate. Curing cancer, he emphasizes, is always the primary goal, but the team also wants to preserve the best possible quality of life. If a tumor can be completely eradicated without removing the rectum, a patient may, in the best-case scenario, avoid both major surgery and a stoma. That framing captures the philosophy driving a broader international movement in rectal oncology: the recognition that survival alone is no longer the only meaningful endpoint, and that the functional and psychological toll of radical treatment deserves equal weight in treatment planning.

The new therapy introduced at Tays is known medically as high-dose-rate brachytherapy, or HDR brachytherapy, delivered in a contact configuration. Unlike external beam radiotherapy, in which radiation is generated by a machine positioned outside the body and must travel through healthy tissue to reach its target, contact brachytherapy places the radiation source directly against the tumor. A device is inserted into the rectum and positioned at the tumor surface, allowing clinicians to deliver a very high dose of radiation precisely where it is needed. The treatment utilizes an iridium-192 radiation source, a radioactive isotope commonly employed in brachytherapy applications because it emits energetic gamma rays suitable for destroying cancer cells while permitting rapid dose falloff at a distance.

That physical property, the steep gradient of dose, is the key technical advantage of the method. Because the radiation source sits immediately adjacent to the tumor, the cancer cells receive a devastating dose while the surrounding healthy tissues, including the bowel wall beyond the tumor, the bladder, and nearby nerves and blood vessels, are largely spared. In conventional external radiotherapy, achieving that kind of selectivity is far harder, and dose limits imposed by surrounding organs often constrain how much radiation the tumor itself can safely receive. Contact brachytherapy effectively sidesteps that constraint by shortening the distance between source and target to millimeters, exploiting the inverse relationship between distance and radiation intensity to concentrate therapeutic energy with remarkable precision.

The treatment is not appropriate for every patient with rectal cancer, and the hospital is careful to emphasize that point. Eligibility is assessed by a multidisciplinary team that includes colorectal surgeons, oncologists, radiation oncologists and radiologists. Tumor size, depth of invasion into the bowel wall, location, and the presence or absence of spread to lymph nodes or distant organs all factor into the decision. One particularly important patient group consists of frail and elderly people for whom major rectal cancer surgery may be especially burdensome or may even pose an excessive risk. It is estimated that more than 100 such patients in Finland every year could stand to benefit from an effective alternative to radical resection, a figure that gives a sense of the immediate clinical demand even before broader patient groups are considered.

The introduction of contact brachytherapy at Tays is part of a wider shift in thinking that has transformed rectal cancer treatment over the past several years. International studies have demonstrated that in some patients, the tumor disappears completely following a combination of radiotherapy and anti-cancer medication, a result termed a complete clinical response. In those cases, careful surveillance may be considered as an alternative to immediate surgery. This strategy is known as organ-preserving treatment, or the watch-and-wait approach. Patients are monitored closely with regular endoscopic examinations and imaging so that any residual tumor or local regrowth can be detected early and treated surgically if necessary. For patients who maintain a complete response over the long term, the rectum is preserved, along with continence and quality of life.

Tumor-targeted brachytherapy is designed to push that strategy further by increasing the number of patients who achieve a complete clinical response in the first place. By intensifying the local radiation dose delivered to the tumor, clinicians hope to eradicate more cancers outright and thereby expand the pool of patients who can safely retain their rectum. As Seppälä explains, the goal is not to treat the cancer less intensively, but more precisely. The team wants to identify a treatment that is sufficiently effective for each patient while avoiding treatments and side effects that would yield no additional benefit. In other words, the intensification is aimed at the tumor itself, not at the patient as a whole, which is precisely where the dose-concentrating physics of brachytherapy offers its advantage.

The clinical innovation is embedded in a structured research framework. The new treatment is linked to the NORPPA research programme, coordinated by Tampere University and Tampere University Hospital, which is developing new organ-preserving treatment approaches for rectal cancer. The research network includes hospitals from across Finland and Estonia, creating a multinational cohort infrastructure capable of generating meaningful evidence about outcomes. The next phase, the NORPPA-2 study, is due to begin in 2027 and will investigate the effectiveness of HDR brachytherapy as part of an organ-preserving treatment strategy. The study will examine how effectively tumor eradication can be achieved by intensifying local radiotherapy and, critically, how many patients can avoid major surgery as a result.

The ambitions of the research programme extend beyond radiation alone. If local radiotherapy proves sufficiently effective against the tumor, the researchers will also investigate whether some patients could be treated without chemotherapy, sparing them the substantial systemic side effects associated with cytotoxic drugs. And if the study confirms the effectiveness and safety of the new method, the group of rectal cancer patients offered organ-preserving treatment as an alternative to surgery could expand significantly in the future. For a disease diagnosed three-quarters of a million times each year, the implications are far-reaching. What is emerging in Tampere is a vision of rectal cancer care in which the question is no longer simply how to remove the cancer, but how to destroy it with the least possible collateral damage to the body and the life that continues after treatment. The iridium-192 source inserted through the rectum may look unassuming, but it represents a deliberate rethinking of the trade-offs that have long been accepted as the price of cure.

Subject of Research: High-dose-rate contact brachytherapy as an organ-preserving treatment for rectal cancer

Article Title: Novel radiotherapy may save increasingly many rectal cancer patients from surgery and stoma

Article References: Novel radiotherapy may save increasingly many rectal cancer patients from surgery and stoma. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: rectal cancer, HDR brachytherapy, contact radiotherapy, organ preservation, watch-and-wait, stoma avoidance, iridium-192, Tampere University Hospital, NORPPA study, radiation oncology, multidisciplinary cancer care, quality of life

The research team, led by Jitlada Khonglim and Krittiya Korphaisarn of the Division of Medical Oncology at Mahidol University’s Faculty of Medicine, analyzed 339 patients with stage II or III locally advanced rectal cancer who completed preoperative treatment between January 2018 and October 2023. Rather than enrolling patients in a randomized trial, the investigators combined retrospective and prospective data from routine clinical practice, capturing the messier realities of patient adherence, comorbidities, and treatment delays that trials often exclude. Patients were divided into three groups according to the strategy their multidisciplinary team selected: conventional neoadjuvant chemoradiotherapy followed by surgery, total neoadjuvant therapy in which chemotherapy precedes and follows radiation before surgery, and neoadjuvant chemoradiotherapy combined with perioperative chemotherapy.

The distribution of patients across these arms reflected real-world decision-making rather than protocol-driven assignment. Conventional neoadjuvant chemoradiotherapy was used in 156 patients, or 46 percent of the cohort, while 152 patients, 45 percent, received total neoadjuvant therapy. The remaining 31 patients, just 9 percent, were treated with the combined chemoradiotherapy and perioperative chemotherapy approach. This imbalance matters for interpretation, because the smallest group carries the widest statistical uncertainty, a caveat the authors themselves emphasize when discussing their results.

The study’s central endpoint was pathological complete response, the moment when a pathologist examines the surgically removed tumor under the microscope and finds no surviving cancer cells. This outcome is more than a laboratory curiosity. Patients whose tumors vanish completely before surgery tend to live longer without recurrence, and in selected cases a complete clinical response can open the door to a watch-and-wait strategy that spares patients the operation entirely. In this cohort, 27 patients achieved a clinical complete response and were managed without immediate surgery, while 24 patients experienced disease progression during preoperative treatment, underscoring that intensifying therapy is not universally beneficial.

Among the 274 patients for whom pathological data were available, the differences between strategies were striking. Pathological complete response was achieved by only 11 percent of patients treated with conventional chemoradiotherapy, 15 of 131 patients. Total neoadjuvant therapy more than doubled that figure, reaching 24 percent, or 27 of 114 patients. The combined chemoradiotherapy and perioperative chemotherapy group performed best of all at 31 percent, with 9 of 29 patients achieving a complete pathological response, though the authors caution that this small subgroup makes the estimate fragile. When the researchers ran multivariable analysis to separate true treatment effects from confounding factors, two variables emerged as independently associated with complete response: poorly differentiated tumor histology, which carried an odds ratio of 7.1 with a P value of 0.018, and treatment with either total neoadjuvant therapy or the combined approach, with an odds ratio of 2.37 and a P value of 0.03.

The survival analysis added an important layer of nuance. Patients who achieved a pathological complete response had dramatically better outcomes than those who did not, with a hazard ratio of 0.19 for three-year event-free survival and 0.12 for overall survival, both statistically significant at P less than 0.001. In practical terms, eradicating every visible cancer cell before surgery was among the strongest predictors of staying alive and recurrence-free. Yet when the researchers compared the three treatment strategies against one another directly, they found no significant differences in event-free survival or overall survival between the groups. The higher response rates of the intensified regimens did not, within the follow-up window of this study, convert into longer lives.

One of the most revealing findings concerns chemotherapy completion, a metric that clinical trials frequently report but real-world practice often undermines. Patients in the conventional chemoradiotherapy group completed their planned chemotherapy only 57 percent of the time. In the total neoadjuvant therapy group, completion climbed to 87 percent, and in the combined perioperative group to 68 percent, a difference that was highly significant at P less than 0.001. The explanation lies in treatment sequencing. When chemotherapy comes first, patients are typically healthier, less fatigued, and free of the side effects of pelvic radiation, making them far more likely to tolerate and finish the full course. Radiation followed by surgery often leaves patients too depleted to complete adjuvant chemotherapy, which historically was the standard sequencing.

These results arrive at a moment when the standard of care for locally advanced rectal cancer is actively shifting. Total neoadjuvant therapy gained prominence after large randomized trials demonstrated that delivering all systemic therapy upfront improves response rates and allows earlier assessment of treatment effect. Guidelines in many countries now recommend the approach, but guideline recommendations rest heavily on trial populations that tend to be younger, fitter, and more adherent than the average clinic patient. The Siriraj data provide reassurance that the pathological response advantage of total neoadjuvant therapy persists in routine practice, and that the regimen is actually delivered more completely in the real world, not less.

At the same time, the study tempers expectations about what those response gains mean for survival. The absence of a survival difference among the three strategies could reflect insufficient follow-up time, the modest sample size, or the possibility that salvage treatments after recurrence narrow the gap between groups. It could also mean that pathological complete response, while a powerful prognostic marker within any treatment arm, is an imperfect surrogate for survival benefit across different sequencing strategies. This distinction matters for ongoing trials that use response rates as primary endpoints, and it reinforces the need for longer follow-up of real-world cohorts before declaring any strategy definitively superior.

For clinicians and patients weighing options today, the study offers practical guidance. Total neoadjuvant therapy appears to be the more reliable way to deliver the full drug regimen and to maximize the chance of complete tumor eradication, which itself predicts excellent three-year outcomes. The combined chemoradiotherapy and perioperative approach showed the highest response rate of all, but with only 31 patients it remains an open question rather than an established alternative. The authors, whose work was conducted without dedicated funding and approved by the Siriraj Institutional Review Board under protocol Si 106/2022, followed STROBE reporting guidelines and published their findings open access. As watch-and-wait strategies and organ preservation move closer to the mainstream, knowing which preoperative pathway most often empties the rectum of cancer, and which patients are most likely to reach that goal, becomes one of the most consequential decisions in modern rectal cancer care.

Subject of Research: Preoperative treatment strategies and pathological complete response in locally advanced rectal cancer

Article Title: Clinical outcomes of different preoperative treatment approaches in locally advanced rectal cancer: real-world experience

Article References: Khonglim, J., Angkathunyakul, N., Pongpaibul, A., Petsuksiri, J., Veerasarn, V., Riansuwan, W., Chinswangwatanakul, V., Akewanlop, C., & Korphaisarn, K. (2026). Clinical outcomes of different preoperative treatment approaches in locally advanced rectal cancer: real-world experience. BMC Cancer. https://doi.org/10.1186/s12885-026-17078-9

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17078-9

Keywords: rectal cancer, total neoadjuvant therapy, chemoradiotherapy, pathological complete response, event-free survival, overall survival, neoadjuvant chemotherapy, watch-and-wait, real-world evidence, oncology, radiotherapy, surgical oncology