PI-RADS评分1~2分患者诊断前列腺癌的危险因素分析

Risk factors of prostate cancer in men with PI-RADS 1-2 lesions by multiparametric MRI

目的探讨多参数MRI PI-RADS评分1~2分患者前列腺癌及有临床意义前列腺癌(CsPCa)的检出率,分析该类患者诊断前列腺癌的危险因素。方法回顾性分析2011年7月至2018年6月行多参数MRI检查并行经直肠12针前列腺系统穿刺的196例患者的临床资料。患者年龄(66.6±9.0)岁,中位前列腺特异性抗原(PSA)7.44(4.93,10.98)ng/ml,中位前列腺体积63(43,78)ml。196例PI-RADS评分1~2分;28例PSA<4 ng/ml,前列腺指检异常;168例PSA>4 ng/ml。前列腺癌如满足以下任一条:PSA密度>0.15 ng/ml^(2),Gleason评分>6分,≥3针阳性,肿瘤≥50%穿刺长度,则诊断为CsPCa。分析前列腺癌及CsPCa的危险因素,单因素分析采用χ2检验或Fisher’s确切概率法,多因素分析采用logistic回归。结果196例中42例(21.4%)病理证实为前列腺癌,其中30例(15.3%)为CsPCa。多参数MRI诊断前列腺癌的阴性预测值为78.6%(154/196),诊断CsPCa的阴性预测值为84.7%(166/196)。单因素分析结果显示,患者年龄、PSA密度越高,前列腺癌阳性率越高;年龄、PSA、PSA密度越高,f/tPSA越低,则CsPCa的比例越高,差异均有统计学意义(P<0.05)。多因素logistic回归分析结果显示,PSA密度>0.15 ng/ml^(2)(OR=2.94,95%CI 1.45~5.95,P<0.05)是前列腺癌的独立危险因素;年龄>70岁(OR=2.49,95%CI 1.22~5.07)、f/tPSA<0.2(OR=3.70,95%CI 1.25~11.23)、PSA密度>0.15 ng/ml^(2)(OR=5.77,95%CI 1.96~16.96)是CsPCa的独立危险因素(均P<0.05)。结论对于PSA升高或前列腺指检异常的PI-RADS评分1~2分患者,前列腺癌检出率为21.4%,PSA密度>0.15 ng/ml^(2)是前列腺癌的独立危险因素;CsPCa检出率为15.3%,年龄>70岁、f/tPSA<0.2、PSA密度>0.15 ng/ml^(2)是其独立危险因素。

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.