Treatment patterns and survival in metastatic castration-sensitive prostate cancer in the US Veterans Health Administration

Cancer Med. 2021 Dec;10(23):8570-8580. doi: 10.1002/cam4.4372. Epub 2021 Nov 2.

Abstract

Background: Limited real-world data exist on treatment patterns and outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC).

Methods: A retrospective cohort study was conducted, using the Veterans Health Administration claims database (April 2013-March 2018). Among 369,734 prostate cancer patients, we selected all men who developed metastases within 90 days before or after medical/surgical castration and who received androgen deprivation therapy (ADT). Patients were categorized into four cohorts: ADT-only (± <90-day nonsteroidal anti-androgen [NSAA] use), ADT + NSAA, ADT + docetaxel, and ADT + abiraterone. Main outcomes were treatment patterns, time-to-progression to metastatic castration-resistant disease, and overall survival. Multivariable analysis and sensitivity analysis were conducted.

Results: Of 1395 patients, 874 (63%) received ADT-only, 338 (24%) received ADT + NSAA, 108 (8%) received ADT + docetaxel, and 75 (5%) received ADT + abiraterone. Proportions on ADT-only and ADT + NSAA declined (from 66% to 60% and from 31% to 17%, respectively) over the study period, while proportions prescribed ADT + docetaxel or abiraterone increased from 3% to 9% and from 1% to 15%, respectively. Patients treated with ADT + NSAA had similar risks of castration-resistant disease (hazard ratio [HR] 1.05; 95% confidence interval [CI]: 0.87, 1.26) and overall mortality (HR 1.22; 95% CI: 0.97, 1.54) as ADT-only.

Conclusions: Most patients with mCSPC initiating ADT received ADT-only or ADT + NSAA, despite the emergence of docetaxel and novel hormonal therapies. Even in the most recent period (2017 to early 2018), only 24% of men received intensified therapy with agents known to prolong survival versus ADT-only. These data in real-world clinical practice suggest substantial room for improved outcomes in patients with mCSPC.

Keywords: LHRH agonist; LHRH antagonist; anti-androgen; overall survival; prostate cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abiraterone Acetate / administration & dosage
  • Aged
  • Androgen Antagonists / administration & dosage
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Docetaxel / administration & dosage
  • Humans
  • Male
  • Prostatic Neoplasms, Castration-Resistant / drug therapy*
  • Prostatic Neoplasms, Castration-Resistant / mortality*
  • Retrospective Studies
  • Survival Analysis
  • United States
  • Veterans Health*

Substances

  • Androgen Antagonists
  • Docetaxel
  • Abiraterone Acetate