Sexually transmitted infections, benign prostatic hyperplasia and lower urinary tract symptom‐related outcomes: results from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial

Objective To examine whether a history of sexually transmitted infections (STIs) or positive STI serology is associated with prevalent and incident benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS)‐related outcomes in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Methods Self‐reported history of STIs (gonorrhoea, syphilis) was ascertained at baseline, and serological evidence of STIs (Chlamydia trachomatis, Trichomonas vaginalis, human papillomavirus (HPV)‐16, HPV‐18, herpes simplex virus type 2, human herpesvirus type 8 and cytomegalovirus) was detected in baseline serum specimens. We used data collected on the baseline questionnaire, as well as results from the baseline prostate‐specific antigen (PSA) test and digital rectal examination (DRE), to define prevalent BPH/LUTS‐related outcomes as evidence of LUTS (self‐reported diagnosis of an enlarged prostate/BPH, BPH surgery or nocturia [waking ≥2 times/night to urinate]) and evidence of prostate enlargement (PSA > 1.4 ng/mL or prostate volume ≥30 mL) in men without prostate cancer. We created a similar definition of incident BPH using data from the follow‐up questionnaire completed 5–13 years after enrolment (self‐reported diagnosis of an enlarged prostate/BPH or nocturia), data on finasteride use during follow‐up, and results from the follow‐up PSA tests and DREs. We used Poisson regression with robust variance estimation to calculate prevalence ratios (PRs) in our cross‐sectional analysis of self‐reported (n = 32 900) and serologically detected STIs (n = 1 143) with prevalent BPH/LUTS, and risk ratios in our prospective analysis of self‐reported STIs with incident BPH/LUTS (n = 5 226). Results Generally null results were observed for associations of a self‐reported history of STIs and positive STI serologies with prevalent and incident BPH/LUTS‐related outcomes, with the possible exception of T. vaginalis infection. This STI was positively associated with prevalent nocturia (PR 1.36, 95% confidence interval (CI) 1.18–1.65), prevalent large prostate volume (PR 1.21 95% CI 1.02–1.43), and any prevalent BPH/LUTS (PR 1.32 95% CI 1.09–1.61); too few men had information on both STI serologies and incident BPH/LUTS to investigate the associations between T. vaginalis infection and incident BPH/LUTS‐related outcomes. Conclusions Our findings do not support associations of several known STIs with BPH/LUTS‐related outcomes, although T. vaginalis infection may warrant furt