The core idea is called lipid metabolic reprogramming. Healthy cells take up and synthesise fats in carefully balanced amounts, using them to build membranes, store energy, and send signals. Cancer cells throw that balance into disarray. To divide relentlessly, a tumour cell must manufacture enormous quantities of new membranes, and the raw material for those membranes is fatty acids and cholesterol. NSCLC cells therefore crank up both the import of lipids from their surroundings and their own internal fat factories, a process known as de novo lipogenesis. The review details how this heightened lipid metabolism satisfies the biosynthetic and energetic demands of the tumour while simultaneously generating signalling molecules that remodel the tumour microenvironment, the complex neighbourhood of immune cells, fibroblasts, and blood vessels in which the cancer lives.

At the molecular level, the machinery of this reprogramming is intricate. Glucose and glutamine that would otherwise be burned for energy are diverted into citrate, which the enzyme ATP citrate lyase, or ACLY, cleaves in the cytoplasm to supply acetyl-CoA for fatty acid synthesis. Acetyl-CoA carboxylase, ACC, then commits this substrate to the fatty acid pathway, and fatty acid synthase, FASN, assembles the growing carbon chains. The master transcriptional regulator behind much of this activity is SREBP, the sterol regulatory element-binding protein, whose activation is promoted by well-known oncogenic drivers in lung cancer, including mutant KRAS, EGFR, ALK, and the transcription factor MYC. Alongside synthesis, tumour cells ramp up lipid uptake through surface proteins such as CD36, the fatty acid transporter family FATP, and receptors for low-density lipoprotein, then stash the cargo in lipid droplets, organelles that act as intracellular fat warehouses. When energy is scarce or the cell is under stress, fatty acid oxidation, driven by enzymes such as carnitine palmitoyltransferase 1, CPT1, releases that stored energy inside mitochondria.

What makes the picture especially compelling is that different histological and molecular subtypes of NSCLC lean on lipids in distinct ways. Lung adenocarcinoma, the most common subtype, frequently shows enhanced de novo lipogenesis tied to KRAS and LKB1 mutations, while squamous cell carcinoma displays its own lipid signatures. The review also highlights how lipid metabolism intersects with resistance to targeted therapies: tyrosine kinase inhibitors that block EGFR or ALK, for example, can be blunted when tumour cells compensate by shifting their energy supply toward fatty acid oxidation. Lipid droplets can also buffer cytotoxic stress, and enzymes such as stearoyl-CoA desaturase 1, SCD1, which converts saturated into monounsaturated fatty acids, help tumour cells manage the lipotoxic and oxidative stresses that chemotherapy and radiotherapy inflict. In other words, the lipid network is not just a growth engine but a survival kit.

Perhaps the most striking section of the review concerns the tumour microenvironment. Lipids do not stay politely inside tumour cells. Tumours release fatty acids, prostaglandins, leukotrienes, and other lipid mediators that re-educate nearly every cell type around them. Tumour-associated macrophages, for instance, can be pushed toward a pro-tumour phenotype by lipid signals such as prostaglandin E2, and in malignant pleural effusions, foamy macrophages laden with ingested lipid accumulate and dampen antitumour immunity. Cancer-associated fibroblasts, meanwhile, can donate lipids to tumour cells, acting as metabolic supply depots. Myeloid-derived suppressor cells exploit fatty acid oxidation to fuel their immunosuppressive activity, and even dendritic cells, the sentinels that launch T cell responses, can be paralysed by lipid accumulation that disrupts their antigen-presenting machinery.

The consequences for T cells, the workhorses of modern cancer immunotherapy, are particularly sobering. The review describes how high lipid levels in the microenvironment drive CD8-positive tumour-infiltrating lymphocytes into an exhausted state, characterised by loss of effector function and upregulation of inhibitory receptors such as PD-1, TIM-3, and LAG-3. Regulatory T cells, by contrast, can thrive on fatty acid oxidation, giving them a metabolic advantage over the antitumour T cells they suppress. Cholesterol and its metabolites add further layers of complexity, with certain cholesterol pools supporting T cell function while oxysterols and related derivatives can promote immune evasion. This metabolic crosstalk offers a mechanistic explanation for why immune checkpoint inhibitors, which have transformed NSCLC treatment, still fail in a substantial fraction of patients: the lipid-rich microenvironment itself may be sabotaging the immune response the drugs are meant to unleash.

All of this biology points toward a tempting therapeutic strategy: starve the tumour of its lipid advantage. Preclinical studies have produced encouraging results with inhibitors of FASN, SCD1, ACC, ACLY, and CPT1, as well as blockers of lipid uptake through CD36 and inhibitors of the mevalonate pathway that supplies cholesterol and lipid-modified signalling proteins. Some of these approaches have also shown synergy with EGFR tyrosine kinase inhibitors and with immune checkpoint blockade in laboratory models, raising hopes for rational combination regimens. The review notes preliminary clinical signals as well. In a phase I study of an FASN inhibitor, 64 percent of patients with KRAS-mutant NSCLC remained progression-free for more than twelve weeks on monotherapy, compared with none of the six patients with KRAS-wildtype disease, a statistically significant difference that hints at a biomarker-defined patient population worth pursuing.

Yet the authors are refreshingly candid about the gap between promise and practice. No lipid-targeted therapy has so far demonstrated clinically meaningful efficacy in unselected NSCLC patients. The reasons are fundamental rather than incidental. Lipid metabolism is essential to every cell in the body, so systemic inhibition risks toxicity to the liver, the immune system, and other lipid-dependent tissues, a problem of target selectivity. Tumour-type specificity matters too: strategies that work in adenocarcinoma may fail in squamous disease, and metabolic redundancy allows tumours to reroute around blocked pathways. Clinical validation has largely been confined to specific molecular subtypes, and the field still lacks the biomarkers needed to identify which patients will benefit from which metabolic intervention. The authors argue that realising the therapeutic potential of lipid targeting will require closing these gaps in selectivity, specificity, and validation, guided by a deeper map of the lipid metabolic networks operating inside individual tumours.

Technology is beginning to provide that map. Advances in mass spectrometry, including gas chromatography-mass spectrometry and high-performance liquid chromatography-tandem mass spectrometry, now allow researchers to profile hundreds of lipid species in tumour samples, while single-cell approaches are revealing how lipid handling differs between individual tumour cells and their neighbours. Such tools could eventually yield lipid biomarkers that predict immunotherapy response, identify metabolic vulnerabilities, and monitor treatment resistance in real time. The review also points to the potential of repurposing existing drugs that touch lipid pathways, from statins that inhibit HMG-CoA reductase to agents affecting lipid signalling, though it cautions that epidemiological signals must be tested in rigorous prospective trials before any clinical recommendations change.

The broader message of this review is that the Warburg-era focus on glucose, while enormously productive, captured only half of the metabolic story of cancer. Lipids are simultaneously fuel, building material, signalling currency, and a language by which tumours speak to their surroundings. In NSCLC, that language appears to shape immune escape, therapy resistance, and disease progression in ways that are only now coming into focus. If the field can convert its extensive preclinical rationale into subtype-specific, biomarker-guided clinical strategies, lipid metabolic reprogramming may finally move from the pages of review articles into the oncology clinic, offering new options for patients whose tumours have exhausted the current arsenal.

Subject of Research: Lipid metabolic reprogramming and its role in non-small cell lung cancer progression, tumour microenvironment crosstalk, and therapeutic targeting

Article Title: Lipid metabolic reprogramming in NSCLC: mechanisms, microenvironment crosstalk, and therapeutic opportunities

Article References: Chen, S., Zhang, H., Luo, Q., You, S., Du, P., Chen, L., Zhang, D., & Meng, R. (2026). Lipid metabolic reprogramming in NSCLC: mechanisms, microenvironment crosstalk, and therapeutic opportunities. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-08854-z

Image Credits: AI Generated

DOI: 10.1186/s12967-026-08854-z

Keywords: non-small cell lung cancer, lipid metabolism, metabolic reprogramming, tumour microenvironment, fatty acid oxidation, de novo lipogenesis, FASN inhibitor, immune checkpoint inhibitors, tumour-associated macrophages, KRAS mutation, therapy resistance, cancer metabolism

The study, published in Annals of Gastroenterological Surgery, assembled clinical data from 18 Japanese medical institutions, most of them high-volume board-certified training centers, covering patients who underwent initial curative-intent liver resection between January 2006 and December 2016. Of 1251 patients initially screened, 584 met the strict inclusion criteria, which required a known KRAS mutation profile, complete follow-up data, and exclusion of palliative R2 resections and BRAF-mutant tumors. The cohort was predominantly male with a median age of 66 years, and about a quarter of patients had right-sided primary colorectal tumors. Nearly two-thirds had nodal metastases from the primary tumor, almost 70 percent presented with synchronous liver metastases, and during a median follow-up of 44.1 months, a striking 79.1 percent of patients developed tumor recurrence—figures that underscore the aggressive nature of this disease even after apparently curative surgery.

At the heart of the investigation lies the KRAS oncogene, whose mutational status has become indispensable for designing treatment strategies in the era of targeted molecular therapy. Using Sanger sequencing of codons 12 and 13 on formalin-fixed paraffin-embedded tissue, the researchers detected KRAS mutations in 36.8 percent of patients. Mutant tumors were significantly more common in right-sided colon cancers, echoing the well-established embryological and molecular divide between the midgut-derived right colon and the hindgut-derived left colon and rectum. Critically, the survival analysis revealed that KRAS mutation was associated with both shorter recurrence-free survival and shorter overall survival across the entire cohort: median overall survival was 47.3 months for mutant carriers versus 70.6 months for wild-type patients, with five-year survival of 36.8 percent versus 55.6 percent respectively.

Yet the most provocative finding concerned geography within the colon itself. When the analysis was stratified by primary tumor sidedness, the prognostic power of KRAS mutation vanished on the right side and intensified on the left. Among patients with left-sided primaries, KRAS mutation conferred significantly worse overall and recurrence-free survival, with median overall survival of 44.2 months versus 69.4 months for wild-type disease. Among right-sided patients, by contrast, survival curves for mutant and wild-type tumors were statistically indistinguishable. This asymmetry suggests that the biological pathways driving metastatic behavior differ fundamentally according to embryological origin, and it cautions against treating KRAS as a universal prognostic marker. It also raises the possibility that right-sided disease harbors other, still unidentified molecular determinants—such as BRAF mutations or microsatellite instability—that may dominate its clinical course.

The second pillar of the study is the tumor burden score, or TBS, an elegant geometric construct that captures the cumulative impact of tumor size and number on a single continuous scale. Each patient is assigned coordinates on a Cartesian plane according to maximum tumor diameter and lesion count, and the Pythagorean distance from the origin yields the score. In this cohort, TBS grading stratified overall survival more powerfully than tumor size or number alone. But here, too, the interplay with genetics proved decisive: among KRAS wild-type patients, TBS grades separated median survival from 87.1 months in the low-burden group down to 43.8 months in the high-burden group, whereas among KRAS-mutant patients the survival curves collapsed into statistical sameness. In other words, a KRAS mutation appeared to define prognosis entirely independently of the anatomical burden of liver disease—a finding with profound implications for how tumor biology and tumor morphology should be weighed against each other.

Multivariate Cox regression distilled five independent preoperative predictors of survival: primary tumor nodal metastasis, KRAS mutation, extrahepatic disease, high tumor burden score, and elevated CA19-9 above 40 units per milliliter. Notably, CEA—the traditional tumor marker of colorectal cancer—did not survive multivariate adjustment, whereas CA19-9 did, a choice consistent with recent CRLM-specific studies that have demonstrated the prognostic relevance of CA19-9 even in patients receiving preoperative chemotherapy. These five variables were then integrated into a graphical nomogram that assigns weighted points to each factor and converts the summed total into predicted three- and five-year survival probabilities. Unlike categorical scoring systems, the nomogram preserves the relative weighting of individual risk factors and yields a continuous estimate of biological risk at the moment of diagnosis.

The performance data are compelling. When the cohort was divided into low-, medium-, and high-risk groups by total nomogram points, median overall survival separated cleanly into 95.6, 66.0, and 40.4 months respectively, with five-year survival spanning from 73.1 percent in the low-risk group to just 27.9 percent in the high-risk group. The same framework stratified recurrence-free survival with equal consistency, and—crucially—it predicted the pattern of relapse. Higher biological risk was associated with a growing proportion of extrahepatic recurrence involving lung, lymph nodes, and peritoneum, a signature of systemic metastatic propensity rather than merely local liver disease. Measured by Harrell’s C-index, the new model outperformed both the classic Fong clinical risk score of 1999 (0.627 versus 0.553) and the MD Anderson modified clinical risk score (0.627 versus 0.581), with lower Akaike information criterion values confirming superior fit. Internal validation through 1000 bootstrap resamples demonstrated an optimism-corrected C-index of 0.636 and a calibration slope of 0.931, indicating minimal overfitting and good agreement between predicted and observed survival.

It is this recurrence-pattern insight that breathes life into the concept of biological resectability. Even when a tumor is technically resectable by radiological criteria, a high nomogram score signals a hidden risk of systemic spread that surgery alone cannot address. In the high-risk group, roughly 90 percent of patients relapsed after hepatectomy, and in the low- and medium-risk groups recurrence was comparable, suggesting these groups differ qualitatively from high-risk disease in the degree of systemic cancer dissemination. The authors therefore propose distinguishing patients who technically qualify for resection but carry high biological risk as biologically borderline resectable—a category in which hepatic resection may be only one component of multimodal therapy rather than an optimally curative option. Importantly, the framework is presented as hypothesis-generating and complementary to anatomical assessment, not as a validated treatment algorithm, and it requires prospective validation in predominantly technically resectable cohorts.

The study is not without limitations, which the authors address with candor. The nomogram was developed and evaluated within the same multicenter Japanese cohort, so external validation in international populations remains essential. Because KRAS testing was not routine early in the study period, 649 patients with unknown mutation status were excluded, potentially introducing selection bias toward a more contemporary molecularly characterized population. Paired molecular analyses of primary tumors and metastases were unavailable, leaving open the question of KRAS discordance, and extended RAS and co-alteration analyses involving TP53, SMAD4, and other genes were not systematically performed. Dynamic changes in tumor morphology and marker levels during preoperative chemotherapy were likewise not incorporated. The risk-group cutoffs are explicitly exploratory, intended to facilitate interpretation rather than to define fixed biological categories.

Nevertheless, the implications for clinical practice are substantial. The nomogram demonstrates that resectability should be conceived along a continuous biological spectrum rather than as a binary yes-or-no verdict, and it provides an objective, readily computable instrument to locate any individual patient on that spectrum. By fusing molecular information—KRAS status—with geometric tumor burden, nodal status, extrahepatic disease, and CA19-9, the model captures dimensions of metastatic behavior that traditional scores built in the chemotherapy era of the 1990s cannot. Preclinical evidence suggesting that oncogenic Ras signaling cooperates with TP53 loss to promote invasion and systemic spread lends mechanistic plausibility to the observed link between high biological risk and extrahepatic recurrence. As molecular profiling becomes universal in colorectal cancer care, tools of this kind could reshape multidisciplinary decision-making, ensuring that the question asked before liver surgery is no longer only whether the tumor can be removed, but whether removing it will truly serve the patient.

Subject of Research: A nomogram-based continuous biological risk model for defining biologically borderline resectable colorectal liver metastases based on KRAS status and tumor burden.

Article Title: Biological Resectability in Colorectal Liver Metastases: A Nomogram‐Based Continuous Risk Model to Define Borderline Disease

Article References: Umeda, Y., Mitsuhashi, T., Fuji, T., Kojima, T., Koujima, T., Matsuda, T., Satoh, D., Inagaki, M., Takagi, K., & Fujiwara, T. (2026). Biological Resectability in Colorectal Liver Metastases: A Nomogram‐Based Continuous Risk Model to Define Borderline Disease. Annals of Gastroenterological Surgery, Article ags3.70278. https://doi.org/10.1002/ags3.70278

Image Credits: AI Generated

DOI: 10.1002/ags3.70278

Keywords: colorectal liver metastases, KRAS mutation, nomogram, tumor burden score, biological resectability, hepatectomy, CA19-9, overall survival, recurrence-free survival, borderline resectable, prognostic model, colorectal cancer