A renewed research agenda
On August 6, 2026, the US National Cancer Institute published a perspective on functional precision medicine following its July workshop. The approach tests living cancer cells against drugs to help identify treatment candidates. NCI highlighted sample preservation, laboratory standardization and stronger clinical evidence as priorities. This was a research agenda, rather than an announcement that testing had become routine cancer care. Read the NCI perspective.
For genetics researchers, the central question is how measured drug responses can add useful information to a tumour’s molecular profile. A candidate treatment emerging from either source still needs evaluation in the clinical setting.
Two kinds of information
Precision medicine uses genomic information alongside other characteristics to guide medical management. Its scope extends beyond finding a mutation and selecting a matching drug. Environmental and lifestyle information can also contribute, as the NHGRI definition explains.
Functional testing adds an experimental observation: how sampled living cells respond under specified laboratory conditions. Molecular profiling describes alterations in the tumour. These measurements address related questions, but their clinical value depends on whether using them improves decisions and outcomes. NCI presents functional testing as a complement to genomic approaches and calls for rigorous studies of its benefits. NCI’s research priorities.
What the pediatric study established
A relevant proof-of-principle report appeared in Nature Medicine on April 11, 2024. This prospective, non-randomized observational study enrolled 25 children and adolescents with relapsed or refractory cancers, including solid tumours and blood cancers. Recruitment ran from 2019 through 2022. Its main objective was feasibility: returning treatment options within four weeks. Original study.
Drug sensitivity testing succeeded for 21 participants; six ultimately received treatment guided by functional precision medicine. Five of those six had progression-free survival more than 1.3 times that achieved with their preceding regimen. Progression-free survival measures time without disease progression or death; this comparison does not establish an overall-survival benefit. Study results.
The small, heterogeneous cohort and non-random treatment selection limit causal conclusions. The findings support further investigation, while leaving uncertain how much benefit came from using the testing strategy itself. Study design and findings.
Evaluate the whole decision pathway
For future research, the unit of evaluation should be the complete testing strategy. A technically successful assay is one intermediate outcome. A report that reaches a clinician, an available treatment and a patient able to receive that treatment are additional requirements. Each deserves a separate denominator.
Researchers should therefore report enrolment, usable samples, completed assays, returned recommendations, treatment initiation and evaluable outcomes separately. Treatment initiation and completion of a treatment cycle also need distinct definitions. Combining these stages can make an operationally difficult strategy appear more accessible than the data demonstrate.
Define the comparison before interpreting benefit
A useful protocol should specify the treatment decision being changed and the alternative against which it will be assessed. Comparing a patient’s successive regimens can generate a signal, but it cannot by itself isolate the effect of a testing strategy. A prospective comparison should also address who reaches treatment, who deteriorates while waiting and how missing outcomes are handled.
These are study-design implications, rather than additional results from the pediatric cohort. They help translate an encouraging observation into a question that a larger evaluation can answer.
Where research meets established care
NCI’s perspective identifies practical obstacles alongside the evidence gap: functional assays require living material, and laboratories need reproducible handling and testing methods. It also describes approval, coverage and treatment access as unresolved implementation issues. A positive laboratory result alone does not resolve those barriers. NCI workshop priorities.
Researchers should distinguish three claims when communicating results: the assay produced a reliable measurement; the measurement suggested a treatment; using that suggestion improved patient outcomes. Evidence for one claim cannot automatically establish the next. Functional precision oncology offers a testable route to better treatment selection, with clinical adoption dependent on evidence for the specific assay, population and decision.