Trends in total and out-of-pocket cost of cancer care around the first year of diagnosis for the four most common cancers among privately insured nonelderly adults: 2009-2016.

5 Background: To provide a comprehensive evaluation of the trends in treatment pattern, total and out-of-pocket (OOP) costs of cancer care for in the period between 2-month before and 12-month after cancer diagnosis for the privately insured non-elderly adults diagnosed with female breast, colorectal, lung, or prostate cancer. These four cancers represent the four most prevalent cancers in the United States and the 14-month duration captures the most expensive care phase in the cost trajectory of cancer. Methods: We constructed incident cohorts using claims data from the Health Care Cost Institute between 2009 and 2016. We identified treatment modality (cancer-related surgery, systemic therapy, radiation, and other hospitalizations) and calculated associated total and OOP (sum of deductible, coinsurance, and copayment) costs from payment variables. For each cancer, we examined healthcare utilization and cost trends based on the year of diagnosis and conducted logistic regressions to assess the trend in utilization and generalized linear models to evaluate the trend in costs. All estimates are reported in 2020 US dollars. Results: The cohorts consisted of 105,255 breast, 23,571 colorectal, 11,321 lung, and 59,197 prostate cancer patients. Between 2009 and 2016, use of systemic therapy and radiation significantly increased, except for lung cancer. Cancer surgeries significantly increased for breast and colorectal cancer but decreased for prostate cancer, whereas hospitalizations for reasons other than cancer declined for all cancers (p < 0.001). Costs increased for nearly all treatment modalities except for systemic therapy in colorectal and radiation in prostate cancer. Total mean costs per patient had the largest increase in breast cancer (29%, $109,544 to $140,743), followed by lung (11%) and prostate (4%) cancer. Cost increase in colorectal cancer was not statistically significant (P = 0.089). Similar trends were found in median costs. Although not every cancer had significant increase in total costs over time, OOP costs increased > 15% for all cancers, with deductibles accounting for an increasingly proportion. Conclusions: Rising costs of cancer treatments, compounded with increasing cost-sharing increased OOP costs for privately insured, non-elderly cancer patients. Policy initiatives to mitigate financial hardship should consider cost containment as well as insurance reform.