We conducted a retrospective database analysis using medical and pharmacy claims data. Medicare Advantage Prescription Drug Plan members diagnosed with select malignant solid tumors were identified. The pattern of somatic genetic testing for each patient was evaluated from January 2016 through December 2018. Tests were classified by the number of genes tested in the panel: < 50 (small or medium) and ≥ 50 (large). A total of 121,675 eligible patients were identified, with 131,915 unique cancer cases. Overall, 5,457 (4.5%) patients received any panel test from 2016 to 2018.
We found the number of tests performed each quarter increased from 238 in Q1 of 2016 to 755 in Q4 of 2018. The highest number of cases were genitourinary cancers; however, the highest proportion of cancer-related genetic testing was among patients with respiratory cancer.
Across all tumor types, the proportion of large-panel tests performed as a function of all multigene panel tests increased from 20.7% of tests in Q1 of 2016 to 46.4% of tests in Q4 of 2018. The three cancer categories with the highest count of cancer-related panel tests, respiratory cancer, GI cancer, and female reproductive cancer, had a consistently greater proportion receiving a panel test at any point postindex.
Across a variety of cancers, use of somatic, large-panel cancer-related genetic testing, as a proportion of all somatic cancer-related genetic testing, increased from 2016 to 2018, although testing overall was low.