Risk factors of prostate cancer in men with PI-RADS 1-2 lesions by multiparametric MRI / 中华泌尿外科杂志

ABSTRACT

Objective:To evaluate the cancer detection rate in patients with multiparametric magnetic resonance imaging (mpMRI) PI-RADS 1-2 prior to initial biopsy, and analyze the risk factors of prostate cancer.Methods:A total of 196 patients undergoing initial prostate biopsy between July 2011 and June 2018 were retrospectively analyzed. According to ESUR PI-RADS system, the patients’ PI-RADS score was 1 and 2, with the mean age of 66.6±9.0 years, and the median PSA 7.44 ng/ml. Twenty-eight patients were enrolled with PSA<4 ng/ml but with abnormal directeral rectun examination. The rest 168 patients were enrolled with elevated PSA. According to the Epstein prostate risk classification criteria, clinically insignificant prostate cancer was defined as PSA density ≤0.15 ng/ml 2, Gleason score≤6, less than 3 positive needles, <50% puncture length. If any of the above is not met, the diagnosis should be clinically significant prostate cancer(CsPCa). T test or Mann-Whitney U test were used for comparison between groups. Risk factors for diagnosis of prostate cancer and CsPCa were analyzed by chi square test(or Fisher’s exact probability method) and multivariate logistic regression analysis. Results:There were 42(21.4%) patients diagnosed with prostate cancer, 30(15.3%)patients were CsPCa. The negative predictive value of mpMRI was 78.6%(154/196)for prostate cancer overall, and 84.7%(166/196)for CsPCa. Patients with higher age and PSA density were associated with higher possibility of prostate cancer. Higher age, PSA level, PSA density, and lower PSA ratio were associated with higher possibility of CsPCa. Multivariate logistic regression analysis showed that PSA density>0.15 ng/ml 2( OR=2.94, 95% CI 1.45-5.95) was independent risk factor of prostate cancer.Ages over 70 years( OR=2.49, 95% CI 1.22-5.07), PSA ratio<0.2( OR=3.70, 95% CI 1.25-11.23), PSA density>0.15 ng/ml 2( OR=5.77, 95% CI 1.96-16.96) were independent risk factors of CsPCa ( P<0.05). Conclusions:The detection rate of prostate cancer was 21.4% in patients with elevated PSA or abnormal digital prostate examination but with PI-RADS score of 1-2. Higher age and PSA density were associated with higher risk of prostate cancer. The detection rate of CsPCa was 15.3%. Ages over 70 years, PSA ratio<0.2, PSA density>0.15 ng/ml 2 were independent risk factors of CsPCa.