The effect of subsequent immunosuppressant use in organ-transplanted patients on prostate cancer incidence: a retrospective analysis using the Korean National Health Insurance Database

Backgrounds Prostate cancer (PC) is the most common solid organ cancer. However, there is still no definite consensus before and after organ transplantation (TPL). We aimed to analyze whether PC incidence increased in TPL patients with subsequent use of immunosuppressants using the Korean National Health Insurance Database. Methods TPL patients between 2003 and 2015(N = 12,970) were age- and year-matched to non-TPL patients (N = 38,910) in a 1:3 ratio. Multivariate Cox regression analysis adjusted for significant prognostic clinicopathological parameters, including the duration of immunosuppressant agent use (0–300 or > 300 days), and Kaplan–Meier analysis with log-rank test were used to evaluate the association of TPL with PC incidence between the groups. Results Median overall survival was 4.86 years; overall mortality rate was 3.4% (n = 1761). Regardless of differences in baseline characteristics between the groups, multivariate analysis for PC incidence showed that age, immunosuppressant use, and TPL organ subtypes were significant factors for the overall population, whereas only age was significant in the TPL group (p < 0.05). After adjusting for age, underlying disease, and prescribed medication (aspirin, statin), multiple subgroup analysis models for PC incidence were evaluated. PC incidence was increased in the TPL group (hazard ratio [HR] 1.965, p < 0.001); however, PC incidence in the TPL group became insignificant after adjusting for immunosuppressant use (p = 0.194). Kaplan–Meier curves also showed that PC incidence was significantly different according to age and TPL with the use of immunosuppressants between the TPL and non-TPL groups. Conclusions PC incidence was higher in the TPL group using immunosuppressants than in the non-TPL group. Trial registration: The study was retrospectively registered.