Finasteride lowers bladder cancer risk in men, but not in Blacks

Use of finasteride reduces the incidence of bladder cancer in men, as corroborated by findings of a recent study. However, this reduction is observed only in White and Hispanic but not Black men.

The investigators accessed the electronic medical record database at their academic health centre in Bronx, New York, in the US to identify patients diagnosed with benign prostatic hyperplasia between 2000 and 2016. They then distinguished those with a finasteride prescription and those who developed bladder cancer during follow-up.

Competing risk analysis was carried out to assess the associations between finasteride use and bladder cancer risk, adjusting for age, smoking, and race/ethnicity.

Of the 42,406 patients with benign prostatic hyperplasia (mean age 67±12.9 years) included, 27.7 percent were Black and 14.8 percent were Hispanic. A total of 5,698 patients (13.4 percent) were treated with finasteride.

Bladder cancer was detected in 84 finasteride users (1.5 percent) compared to 762 nonusers (2.1 percent; log-rank p=0.003). Finasteride use resulted in a 36-percent reduction in bladder cancer risk (hazard ratio [HR], 0.64, 95 percent confidence interval [CI], 0.51–0.80; p<0.0001) among patients.

Stratification of data by race/ethnicity revealed that finasteride use led to a reduction in bladder cancer risk among White men (HR, 0.61, 95 percent CI, 0.43–0.86; p<0.005) and Hispanic men (HR, 0.44, 95 percent CI, 0.21–0.90; p=0.026). However, no association was found among Black men (HR, 1.01, 95 percent CI, 0.67–1.51; p=0.964).

“Therefore, race/ethnicity represents an important stratification factor for future larger studies on finasteride as chemoprevention for bladder cancer,” the investigators said.