Second primary cancers and hormonal therapies for prostate cancer: A nested case-control study

Area of Science:

• Oncology
• Pharmacovigilance
• Cancer Epidemiology

Background:

• Androgen receptor pathway inhibitors (ARPIs) are used to treat prostate cancer.
• Pre-clinical and clinical studies have not fully excluded a potential risk of second primary cancer (SCP) with ARPIs, particularly enzalutamide (ENZ).

Purpose of the Study:

• To investigate the association between ARPIs (abiraterone [ABI] and enzalutamide [ENZ]) and the risk of developing second primary cancers (SPCs).

Main Methods:

• A case-control study was conducted using the French health claims database (2013-2020).
• Patients initiating androgen-deprivation therapy were included, with cases defined as those diagnosed with SPC after a 12-month latency period.
• Matched controls were selected, and exposure patterns to ABI and ENZ were analyzed with a one-year lag time.

Main Results:

• The study included 147,092 patients, with 7,928 cases of SPC.
• SPCs primarily affected the digestive organs, urinary tract, or lungs.
• Recent, short-term exposure to ENZ was associated with SPC (OR 1.7).
• Recent exposure to ABI for one year or more was also associated with SPC (OR 1.8-2.3).

Conclusions:

• Second primary cancer (SPC) cases were predominantly observed in recently exposed patients, suggesting a potential detection bias.
• The limited number of patients with long-term ARPI exposure precludes definitive conclusions on long-term risks.