Increasing prevalence of metastatic castration-resistant prostate cancer in a managed care population in the United States.

Purpose: Numerous treatment breakthroughs for patients with metastatic castration-resistant prostate cancer (mCRPC) have been demonstrated in clinical trials in the past 15 years. However, real-world evidence on the changing epidemiology and longevity of this population has not been demonstrated. This study assessed prevalence trends for mCRPC over eight years in a large managed care population.

Methods: In a claims database, adult male patients were included with ≥ 1 claim for prostate cancer, pharmacologic/surgical castration, and metastatic disease during the identification period. The index mCRPC date was the first metastatic claim; six months of continuous enrollment before and after was required. Patients with metastatic disease at baseline were excluded. Patients were followed until death, end of study, or disenrollment, whichever was earliest. Total, mCRPC per-prostate cancer, and age-specific prevalence rates were calculated cross-sectionally for each year under study (2010-2017).

Results: Of 343,089 patients identified with a claim for prostate cancer, 3690 mCRPC cases (1.1%) were identified. Incidence (new cases per year) remained relatively constant over the study period while prevalence of mCRPC (total cases per year) increased. mCRPC prevalence increased with increasing age. Total and mCRPC per-prostate cancer prevalence rates increased in monotonic, year-over-year trends from 2010 to 2017, while incidence (new cases per year) of mCRPC remained relatively stable.

Conclusion: This study found increasing prevalence of mCRPC in an insured patient population during the 8-year period, coupled with stable incidence, validating that patients with the disease are living longer. With the addition of androgen receptor-directed therapies and poly(ADP-ribose) polymerase inhibitors in recent years, this trend will likely continue.