Sexual function following radical prostatectomy: a prospective longitudinal study of cultural differences between Japanese and American men.

We conducted a cross-cultural comparison of the recovery of sexual function and bother during the first 2 years after radical prostatectomy (RP) between American and Japanese men. A total of 275 Japanese and 283 American men who underwent RP alone were prospectively enrolled into longitudinal cohort studies of health-related quality of life outcomes. Sexual function and bother (distress) were estimated with English and validated Japanese versions of the UCLA Prostate Cancer Index before RP and 1, 2-3, 4-6, 12, 18 and 24 months after RP. Each subject served as his own control. Japanese men reported lower sexual function scores at baseline, even after adjusted for age, prostate-specific antigen (PSA) and comorbidity (38 vs 61, P<0.001). The two groups had similar baseline sexual bother (70 vs 69, P=0.84). Japanese men had a smaller improvement in sexual function (beta=0.8 vs beta=5.3) and bother (beta=0.2 vs beta=2.9) over time than did the American men postoperatively, after adjusting for baseline score, age, baseline PSA and nerve-sparing. American men were more likely than Japanese men to regain their baseline sexual function by 24 months after surgery (hazard ratio (HR)=1.60; 95% confidence interval (CI)=1.06-2.42). In contrast, American men were less likely than Japanese men to return to baseline sexual bother (HR=0.57; 95% CI=0.44-0.75). This study demonstrates that Japanese and American men experience different patterns of recovery of their sexual function and bother after RP. Ethnicity may be a contributing factor.