血清游离PSA和游离／总PSA在前列腺癌诊断中的价值

Diagnostic Value of Serum Free PSA and the Ratio of Free to Total PSA in the Diagnosis of Prostate Cancer

探讨游离前列腺特异性抗原(FPSA)和游离／总前列腺特异性抗原比值(F／T PSA)在前列腺癌(PC)和良性 前列腺增生(BPH)鉴别诊断中的价值。采用美国DPC公司的酶放大化学发光仪测定89名正常志愿者、85例 PC患者和97例BPH患者血清FPSA和TPSA水平,并计算F／T PSA的比值。结果表明正常男性(41-88岁) 组血清FPSA和TPSA水平与青年组相比明显升高,老年组升高特别明显(P<0．01),直线相关统计分析表明, 年龄与血清FPSA和TPSA水平有显著正相关性(FPSA／年龄:r为0．49-0．51,P<0．01;TPSA／年龄:r为0．44 -0．45,P<0．01);PC组和BPH组血清FPSA、TPSA水平明显高于对照组(P<0．01),而PC组F／T PSA比值 则明显低于BPH组和对照组(P<0．01)。血清TPSA<4．0、4．0-10．0和>10．0μg／L的BPH患者分别占 65．0％、30．9％和4．1％,PC患者分别为5．9％、20．0％和74．1％,经卡方检验,两组间患者的分布差别有极显著 性意义(P<0．01);F／T PSA比值的分段研究显示,在TPSA灰色区,F／T PSA<0．1,提示PC可能性较大 (88．9％),而F／T PSA>0．25时,表明PC可能性很小(6．1％)。提示40岁以上正常男性血清FPSA和TPSA 水平随年龄升高而增加,并与年龄呈明显的正相关;约30．9％的BPH与20．0％的PC患者血清TPSA水平存在 重叠,F／T PSA比值的应用可以明显提高TPSA在灰色区鉴别诊断PC的特异性。

In order to evaluate the value of free prostate specific antigen （FPSA） and F/T PSA ratio in differential diagnosis of benign prostate hyperplasia（BPH） from prostate cancer （PC）, serum FPSA and TPSA levels were measured in 85 patients with PC, 97 BPH and 89 healthy volunteers by chemiluminescence enzyme immunoassay （CLEIA）, and the ratio of F/ T PSA was calculated. The results showed that serum FPSA and TPSA levels were increased in healthy volunteers of 41～88 years old and were significantly higher in healthy volunteers of 61～88 years old than that in 20～40 gear old（P〈0.01）. The correlation analysis showed that FPSA and TPSA were positively correlated with increase of age（FPSA/age： r=0.49～0.51, P d0.01; TPSA/age： r=0.44～0.45, P〈0.01）in healthy volunteers of 41～88 years old. Serum FPSA and TPSA levels were significantly higher in PC group and BPH group than those in healthy volunteers （P〈0.01）. F/T PSA ratio of the PC group was lower than that of the BPH group and healthy volunteers （P〈0.01）. In BPH patients serum TPSA〈4.0, 4.0～10.0 and 〉10.0μg/L were 65.0%, 30.9% and 4.1%, respectively, while they were 5.9%, 20.0% and 74.1% in PC patients （P〈0.01）. When the TPSA value was between 4.0～10.0μg/L and the ratio of F/T PSA was at 0.10 and below, the probability of PC was larger（88.9%）. But the ratio of F/T PSA was at 0.25 and above, the probability of PC was smaller（6.2%）. Serum FPSA and TPSA both increased with age in healthy volunteers of 41～88 years old and were positively correlated with age. There were about 30.9% of BPH and 20.0% of PC patients with overlapping of TPSA level. Our conclusion is that the F/T PSA ratio can significantly enhance the specificity for PC diagnosis, especially when the TPSA is within the diagnostic gray zone.