Finasteride Use and Risk of Bladder Cancer in a Multiethnic Population

Abstract

Purpose: Finasteride use has been associated with a reduced incidence of bladder cancer. However, the majority of studies have been conducted primarily in East Asian or White populations. Given differences in the incidence of bladder cancer among racial/ethnic groups, it is important to determine whether the effect of finasteride use on bladder cancer varies by race/ethnicity. Materials and Methods: We identified all patients with a diagnosis of benign prostatic hyperplasia between 2000 and 2016 at our academic health center in Bronx, New York via an electronic medical record database. We then identified patients who were prescribed finasteride, and those who developed bladder cancer during followup. We used competing risk analysis to examine associations of finasteride use with risk of bladder cancer, adjusting for age, smoking and race/ethnicity. Results: We identified 42,406 patients with benign prostatic hyperplasia (aver-ageAESD age 67AE12.9 years), of whom 27.7% were Black and 14.8% were Hispanic. Finasteride was prescribed in 5,698 patients (13.4%). Bladder cancer was diagnosed in 84 of 5,698 finasteride users (1.5%), compared to 762 of 36,708 nonusers (2.1%, log-rank p[0.003). Finasteride was associated with a 36% reduction in risk of bladder cancer (HR: 0.64, 95% CI: 0.51e0.80; p <0.0001) among all patients. When data were stratified by race/ethnicity, finasteride use was associated with a reduction in risk of bladder cancer in White men (HR: 0.61, 95% CI: 0.43e0.86; p[0.005) and Hispanic men (HR: 0.44, 95% CI: 0.21e0.90; p[0.026), but there was no association among Black men (HR: 1.01, 95% CI: 0.67e1.51; p[0.964). Conclusions: Our study corroborates previous findings that men who are on finasteride have a lower bladder cancer incidence. However, the reduction in risk was seen only in White and Hispanic men, but not among Black men. Therefore, race/ethnicity represents an important stratification factor for future larger studies on finasteride as chemoprevention for bladder cancer.

Impact of Androgen Suppression Therapy on the Risk and Prognosis of Bladder Cancer: A Systematic Review and Meta-Analysis

“…Overall, according to the screening criteria, the systematic review and meta-analysis included 18 studies with a total of 414 007 male patients ( 21 – 38 ) ( Figure 1 ). Eight studies evaluated the effect of AST on bladder cancer incidence ( 22 , 27 , 28 , 30 , 32 – 34 , 38 ). Ten studies examined the effect of AST on bladder cancer recurrence, progression and survival ( 21 , 23 – 26 , 29 , 31 , 35 – 37 ).…”

“…Zhu et al. ( 38 ) indicated that the use of finasteride was associated with significant reductions in the risk of high-grade BCa and non-muscle invasive BCa. In addition, a decrease in the risk of BCa was shown only in Caucasians and Hispanics but not among African Americans.…”

“…Zhu et al. ( 38 ) first demonstrated that after using finasteride, although Hispanic men have a similar reduced risk of bladder cancer compared with Caucasian men, African-American men do not. A possible biological explanation for this observation might be the structural variations in the AR protein across different races.…”

“…A possible biological explanation for this observation might be the structural variations in the AR protein across different races. African Americans are more likely to contain polymorphisms in AR, which causes their AR to become active and independent of DHT binding ( 38 ). The role of AST is not limited to the androgen axis.…”

“…Overall, according to the screening criteria, the systematic review and meta-analysis included 18 studies with a total of 414 007 male patients (21-38) (Figure 1). Eight studies evaluated the effect of AST on bladder cancer incidence (22,27,28,30,(32)(33)(34)38).…”