Background: Clinical biomarker testing practices vary widely in patients with lung and thyroid cancers despite guideline-recommended approaches. This study evaluated the utilization of biomarker codes measured the lifetime total costs of biomarker testing.

Methods: The commercial IBM Marketscan database, a de-identified real-world dataset, was investigated between 1/2015-12/2019. Eligible patients had 2+ lung or thyroid cancer diagnosis codes with no prior cancer; subgroup analyses were limited to metastatic disease. Descriptive statistics were used to evaluate amount paid for all claims with specific genomic biomarker codes (single-gene and comprehensive tests) throughout follow up; costs were adjusted to 2020 US dollars.

Results: The lung cancer cohort included 23,633 (overall)/13,320 (metastatic) patients; the thyroid cancer cohort included 36,867 (overall)/2,241 (metastatic) patients. Among those with metastatic disease, 1+ biomarker codes were observed among 75.8% (lung) and 42.3% (thyroid) patients; only 6.7% and 2.2%, respectively had 1+ code(s) for comprehensive tests. For those with metastatic disease and 1+ biomarker code, the average per-patient total payer costs of all biomarker testing were $1,669 (standard deviation (SD)=$2,933, lung) and ($1,279 (SD=$2,430, thyroid). Total costs for patients whose genomic biomarker testing included at least one code for comprehensive testing were $2,334 (SD=$3,173) and $3,475 (SD=$6259), respectively. By payer type among patients with metastatic lung cancer, the mean costs of all biomarker tests throughout follow up ranged from $1,446 (health maintenance organizations, HMO) to $1,709 (preferred provider organizations, PPO). For patients with metastatic lung cancer whose testing included at least one comprehensive test, the total costs of all biomarker testing ranged from $1,302 (HMO) to $2,633 (point-of-service).

Conclusions: While comprehensive testing adds to the cost of biomarker testing, these data suggest the relatively low lifetime cost biomarker testing in the context of the lung cancer care, which in prior literature is estimated at $100,000-150,000 for first-line therapy alone.