Disparities in utilization of oral anticancer agents and related costs in elderly patients with metastatic renal cell carcinoma in the United States.

Abstract

106 Background: Although survival among patients with metastatic renal cell carcinoma (mRCC) has improved with the introduction of targeted therapies, substantial disparities in mRCC survival persist. The purpose of this study was to identify patient characteristics associated with differential adoption of emerging oral anticancer agents (OAAs) and related costs in the management of mRCC. Methods: SEER-Medicare patients diagnosed with mRCC aged 65 years or older from 2007-2015 continuously enrolled in Medicare Part D benefits for at least 1 year after diagnosis or until death were included. Associations between patient-level characteristics and OAA receipt were analyzed using univariable and multivariable log-binomal regression; associations between patient characteristics, OAA receipt, and total, cancer-specific, and OAA-specific costs in the 12 months following diagnosis were modeled as relative cost ratios using generalized linear regression with a gamma link. Reported costs were adjusted to 2015 dollars. Results: 2,792 patients with mRCC met inclusion criteria; 32.4% received an OAA in the 12 months following diagnosis. The majority of patients receiving an OAA used either sunitinib or pazopanib. Receipt increased slightly over the study period from 2007 (31% of patients) to 2015 (37%). In multivariable-adjusted models, patients of advanced age ( > 80 years RR 0.50; 95% CI 0.42-0.60) or residing in the Southern US (RR 0.83 95% CI 0.70-0.98) were less likely to receive OAAs. Married patients were 20% more likely (RR 1.19; 95% CI 1.04-1.37) to receive OAAs. After multivariable adjustment, receipt of OAAs was associated with higher total and cancer-specific costs, as was Hispanic ethnicity. Among patients receiving an OAA, the cost of OAAs to Medicare increased approximately 7% per year (95% CI 4%-9%), while patient out-of-pocket spending for OAAs decreased approximately 10% per year (95% CI 7%-14%). Out-of-pocket OAA costs were consistently lower for Black, Hispanic, and Other patient race/ethnicity categories compared to the White Non-Hispanic category. Conclusions: Patient characteristics including age at metastatic diagnosis, marital status, geographic region, and certain comorbidities are related to the likelihood of receiving OAAs. Future research is warranted to investigate if such differences in OAA use lead to differences in survival.