Medicare covers tumor testing that most patients don't get

Clinical takeaway: Coverage doesn't guarantee testing. When an older patient with a newly diagnosed solid tumor may be a candidate for targeted therapy, confirm whether guideline-appropriate genomic testing was done rather than assuming it happened.

Medicare spent the last decade removing the coverage barrier to genomic testing, first for tumor mutations in 2018 and then inherited ones in 2020. The assumption was that paying for the tests would get them to patients. A new claims analysis suggests it mostly didn't: use climbed after each policy change but stalled far short of routine adoption.

For some cancers, the genomic result is crucial to the treatment decision. In non-small cell lung cancer, testing can reveal one of several alterations with a matched targeted therapy so guidelines call for it routinely. In others, such as prostate or endometrial cancer, actionable targets are fewer and the yield is lower. Untested tumors matter most where access to effective options hinges on the result; lung cancer is where the study found the clearest shortfall.

Across nearly 400,000 Medicare beneficiaries, any genomic testing rose to 16.7% in 2023 from 6.0% in 2016. But testing with next-generation sequencing (NGS), a comprehensive multi-gene approach, reached only 2.1% by the study's end. Over the full period, 91.4% of patients received no genomic testing at all.

Lung cancer drove most of the real NGS growth, rising to 9.2% from 1.6%. Breast cancer saw the largest jump in any testing but leaned on older single-gene tests rather than NGS. Prostate and endometrial cancer were the reviewed indications that remained near the bottom, which is consistent with fewer actionable targets.

The study used Medicare fee-for-service claims from 2016 to 2023, covering beneficiaries age 66 and older with incident lung, breast, colorectal, prostate, or endometrial cancer, and tracked genomic testing within 180 days of diagnosis. As a claims analysis, it captures whether testing occurred, not tumor characteristics, test results, or whether testing changed treatment, so the findings are associations, not cause and effect.

The study stops short of the question that matters most: whether testing more patients would improve their results. Which cancers justify the hardest push is still an open question, but lung cancer is a likely priority, with common actionable targets and uptake that still trails guidelines by the widest margin.

"Our next goal is to understand why genomic testing, and more specifically, NGS, remains underused and why uptake differs across cancer types and regions. We also plan to study whether receiving genomic testing ultimately leads to greater use of precision therapies and better patient outcomes," said So-Yeon Kang, PhD, MBA, MPH, of Georgetown University.

Source: Kang SY, et al. (2026 July 29) JAMA Netw Open. Genomic Testing Uptake Among Medicare Beneficiaries With Cancer