Impact of lower urinary tract symptoms on prostate cancer risk among Japanese men with prostate-specific antigen <10 ng/mL and non-suspicious digital rectal examination

Objective: To investigate the association between lower urinary tract symptoms status and prostate cancer risk at initial extended biopsy.

Methods: Between 2005 and 2011, the International Prostate Symptom Score was completed on 1467 consecutive men with prostate-specific antigen <10 ng/mL and non-suspicious digital rectal examination. After excluding 308 men treated with alpha-blockers, the remaining 1159 men were enrolled in the present study. Lower urinary tract symptoms status was divided into absent or mild (International Prostate Symptom Score scores of 0-7) and moderate or severe lower urinary tract symptoms (International Prostate Symptom Score scores of 8-35). The risks of prostate cancer diagnosis and high-grade (Gleason score ≥4 + 3) prostate cancer diagnosis in relation to lower urinary tract symptoms status was evaluated using logistic regression. A stratified analysis based on prostate volume (<30 cc, 30-50 cc and >50 cc) was also carried out.

Results: Of 1159 patients, 421 (36.3%) had a positive biopsy and 590 (51.0%) had moderate or severe lower urinary tract symptoms. On multivariate analysis, absent or mild lower urinary tract symptoms had a significant and positive impact on the risk of prostate cancer and high-grade disease (odds ratio 1.64 and 1.70, P = 0.0007 and 0.0121, respectively). Furthermore, the aforementioned findings for prostate cancer detection did not change throughout every prostate volume subgroup. In contrast, in men with prostate volume ≤50 cc, but not in those with prostate volume >50 cc, prostate-specific antigen or %free prostate-specific antigen remained as a significant predictor of prostate cancer.

Conclusion: In men with elevated prostate-specific antigen, absent or mild lower urinary tract symptoms are positively associated with prostate cancer and high-grade disease regardless of the prostate volume. This finding is especially useful in men with enlarged prostates.