Living tumor‑agnostic guidance
A review in JCO Precision Oncology argues for 'living' tumor‑agnostic guidelines that prioritize biomarkers over organ‑based rules, citing examples like pembrolizumab for MSI‑H/dMMR and larotrectinib for NTRK fusions. That shift implies safety assessment and labeling may increasingly hinge on biomarker‑defined populations rather than traditional tumor types. (x.com)
Cancer drug rules were built around body parts: lung cancer got one playbook, colon cancer got another. Precision oncology is breaking that map by asking a different question first: what mutation is driving the tumor, no matter where the tumor started. (fda.gov) A biomarker is a measurable clue inside a tumor, like a fingerprint left at a crime scene. In cancer care, that clue can be a broken repair system, a fused gene, or an unusually high mutation load that tells doctors which drug has a chance to work. (fda.gov) One of the clearest examples is mismatch repair deficiency, which means the cell’s spell-check system for DNA is broken. When that repair system fails, copying errors pile up, and some tumors become easier for immune drugs to recognize. (fda.gov) That is why the Food and Drug Administration gave pembrolizumab a landmark tumor-agnostic approval on May 23, 2017, for unresectable or metastatic cancers that are microsatellite instability-high or mismatch repair deficient. The approval used data from 149 patients across 15 cancer types in five single-arm trials, instead of limiting the drug to one organ like colon or stomach. (fda.gov) Another example is a neurotrophic receptor tyrosine kinase fusion, which is a gene accident that can lock a growth signal in the “on” position. Larotrectinib was approved on November 26, 2018, for adults and children with solid tumors carrying that fusion, as long as the cancer was metastatic or surgery would cause severe harm and no good alternatives remained. (fda.gov) Those approvals changed more than prescribing. They changed the logic of evidence, because regulators were now judging a drug across many tumor types tied together by one molecular feature rather than one organ. (annalsofoncology.org) That creates a maintenance problem for guidelines. A paper in JCO Precision Oncology argues that tumor-agnostic guidance should be “living,” meaning recommendations are updated continuously as new biomarker data, trial results, and diagnostic standards appear. (read.qxmd.com) Living guidelines already exist in one corner of oncology. The American Society of Clinical Oncology launched living guidance for stage IV non-small cell lung cancer in 2022 and has updated it with routine literature reviews through at least March 10, 2025, which gives a working model for faster revisions. (ascopubs.org) The pressure to do this is growing because tumor-agnostic medicine is no longer a one-off exception. A 2025 review in The Oncologist counted nine tumor-agnostic approvals in solid tumors and described them as a major shift in precision oncology. (academic.oup.com) The hard part is that the same biomarker does not behave identically in every cancer. A 2025 Nature Communications study of 295,316 molecularly profiled tumor samples found tissue-agnostic biomarkers in 21.5% of tumors, but it also reported variable clinical benefit across tumor types, which means “same mutation” does not always mean “same outcome.” (nature.com) That is why the next fight is not just over which drug matches which biomarker. It is also over how labels, safety monitoring, and testing standards are written when the relevant patient population is defined by a molecular signature first and an organ second. (fda.gov)
