Systemic Treatments for Advanced Prostate Cancer: Relationship Between Health Insurance Plan and Treatment Costs.

Objectives: The high costs of cancer care can cause significant harm to patients and society. Prostate cancer, the leading nonskin malignancy in men, is responsible for the second-highest out-of-pocket (OOP) payments among all malignancies. Multiple first-line treatment options exist for metastatic castration-resistant prostate cancer (mCRPC); although their costs vary substantially, comparative effectiveness data are limited. There is little evidence of how gross payments made by insurers and OOP payments made by patients differ by treatment and health plan type and how these payment differences relate to utilization. Study Design: Retrospective cohort study. Methods: We used IBM MarketScan databases from 2013-2019 to identify men with prostate cancer who initiated treatment with 1 of 6 drugs approved for first-line treatment of mCRPC. We calculated and compared gross and OOP payments and drug utilization across drug and insurance plan types. Results: We identified 4298 patients who met our inclusion criteria. Insurer payments varied substantially by first-line therapy but were similar across different health plan types, except for docetaxel. OOP payments for a given first-line therapy, in contrast, varied by health plan type. Utilization of first-line therapies varied by plan type in unadjusted analyses, but not after adjusting for patient characteristics. Conclusions: The extent to which patient OOP payments for drugs reflect differences in gross payments made by insurers varies across health insurance plan types. However, even though OOP payments for the same treatment differ across plan types, treatment choice is not significantly different across type of health insurance after controlling for patient characteristics.