单纯PSA异常患者前列腺穿刺活检前接受抗生素治疗的意义探讨

Effectiveness of antibiotic treatment given to patients for an abnormal prostate specific antigen before prostate biopsy

目的探讨单纯PSA升高患者前列腺穿刺活检前行抗生素治疗能否剔除炎症所致PSA升高的影响。方法100例PSA4～10μg／L、f／tPSA〈0．25，而直肠指检与经直肠前列腺B超检查无异常的患者，接受环丙沙星（500mg／次，2次／d）口服3周。抗生素治疗前后分别进行PSA及相关参数的测定，100例均行经直肠前列腺系统12针穿刺活检。分析治疗前后PSA及相关参数的变化与活检结果的关系。结果抗生素治疗3周后，91例tPSA下降，治疗前后平均tPSA分别为（6．5±1．2）和（S．1±1．2）μg／L（P〈0．01），平均下降20．9％。穿刺阳性与阴性患者分别为15例和85例，穿刺阳性患者抗生素治疗前、后的tPSA分别为（6．9±1．4）、（5．8±1．7）μg／L，PSA密度（PSAdensity，PSAD）分别为（0．18±0．09）、（0．15±0．09）mg／L2；穿刺阴性患者抗生素治疗前、后的tPSA分别为（6．4±1．1）、（5．0±1．1）μg／L，PSAD分别为（0．16±0．05）、（0．13±0．04）mg／L2，两组患者抗生素治疗后tPSA与PSAD均明显下降（P〈0．05），但两组问tPSA与PSAD变化值比较差异无统计学意义（P〉0．05）。91例tPSA下降患者中13例（14．3％）穿刺阳性，9例tPSA升高或未变化患者中2例（22．2％）穿刺阳性（P〉0．05）。17例tPSA降至〈4斗g／L，其中3例（17．6％）穿刺阳性。6例抗生素治疗后tPSA为4～10μg／L，而f／tPSA〉0．25，其中1例穿刺阳性。7例tPSA下降幅度〉50％，其穿刺均为阴性。结论单纯PSA异常患者抗生素治疗可使tPSA下降，tPSA小幅下降或治疗后PSA相关参数降至正常范围并不意味着患前列腺癌风险的消失，而tPSA大幅度下降（〉50％）患者患前列腺癌的风险降低，可予严密观察，不进行或推迟进行前列腺穿刺活检。

Objective To analyze the effect of antibiotic treatment on prostate specific antigen （PSA） derivations in patients with and without prostate cancer and to further determine if the changes of PSA values after antibiotic treatment could help to exclude inflammation in the differential diagnosis of an abnormal PSA. Methods A total of 100 patients with lower urinary tract symptoms, a PSA level of 4 to 10 μg/L, free PSA/total PSA （fPSA/tPSA） ratio 〈 0.25, and a negative digital rectal examination and transrectal ultrasonography were enrolled in this study. All patients received 500 mg of ciprofloxacin twice a day for 3 weeks. Free and total PSA values were measured before and after antibiotic treatment. All the patients were then scheduled for 12-core prostate biopsy. Results The mean tPSA value was （6.5 ±1.2） and （5.1 ± 1. 2）~g/L respectively before and after antibiotic treatment （P 〈 0. 01 ）. Ninety-one patients （91.0%） showed tPSA reduction after antibiotic therapy, of which 13 （ 14.3% ） had prostate cancer on biopsy. In 17 cases （18.7%） post-treatment tPSA was less than 4 μg/L. Three of the 17 cases （17.6%） had prostate cancer on biopsy. In 6 of the t00 men post-treatment tPSA was between 4 and 10μg/L and the fPSA/tPSA ratio was above 0.25. One of these cases had prostate cancer on biopsy. Seven cases had a 〉 50% reduction in PSA levels with no positive biopsy results. Although mean total PSA and PSAD decreased after treatment in both groups, the reductions within these parameters were not significantly different between patients with and without prostate cancer （P 〉 0.05 ）. Furthermore, no differences emerged in terms of the changes of other PSA derivations including fPSA and fPSA/tPSA （P 〉 0.05）. Conclusions The PSA levels may change with long-term antibiotic treatment in patients with elevated PSA values. A decrease in PSA after antibiotic treatment does not ruse out the presence of prostate cancer even if PSA decreases to a normal level. But a 〉 50% reduction in PSA levels may be associated with a decreasing risk of prostate cancer, which may allow a postponement of prostate biopsy in selected patients.