Rahardjo D, Kamil S T, Pakasi L S
Department of Urology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia.
Gan To Kagaku Ryoho. 2000 May;27 Suppl 2:563-70.
Prostate-specific antigen (PSA) and PSA density (PSAD) values in Indonesia had been found uniquely much higher than the normal accepted values in western countries. However, PSA more than 10 ng/ml and PSAD above 0.15 in intermediate PSA of 4-10 ng/ml are still indicative of a prostate biopsy. This condition had led to unnecessary biopsies in view of the low incidence of prostatic carcinoma in our country. Our objective is to find alternative serum PSA levels and PSAD cutoff points that enhance the specificity and sensitivity of prostate cancer detection. This retrospective cross-sectional study included 805 consecutive patients from 40 to 95 years old in Sumber Waras Hospital (SWH) and Cipto Mangunkusumo Hospital (CMH) from 1994 to 1997. All patients underwent digital rectal examination (DRE) and transrectal ultrasonography (TRUS) to measure prostate volume. After the serum PSA level was determined and PSAD was calculated, prostate biopsies were performed if the PSA level was greater than 10 ng/ml or PSAD more than 0.15 at intermediate PSA levels of 4-10 ng/ml. The ability of PSA, intermediate PSA level, and PSAD to improve the accuracy of prostate cancer detection was evaluated using univariate analysis. Among 805 patients, 240 patients had PSA level < 4 ng/ml, 230 patients had PSA level 4-10 ng/ml, and 335 had PSA level > 10 ng/ml. Of the 230 patients with intermediate PSA level, 108 had PSAD > 0.15. Thirty-five patients had histologically confirmed prostatic carcinoma, i.e., 3 of 108 patients with PSA 4-10 ng/ml and PSAD > 0.15, and 32 of 335 patients with PSA > 10 ng/ml. There were 105 and 303 unnecessary biopsies in those groups. With a PSA cutoff level of > or = 8 ng/ml, we found 100% sensitivity to prostate cancer. PSAD > or = 0.20 within a PSA level of 8-30 ng/ml gave 100% sensitivity to prostate cancer. Using these new cutoffs there would be 148 biopsies (33.4%) saved. We concluded from this study that the commonly accepted values of serum PSA level and PSAD resulted in many unnecessary biopsies in our patients. Instead, the most sensitive cutoff points to perform prostate biopsy are serum PSA level greater than 8.0 ng/ml, and PSAD of more than 0.20 at an intermediate serum PSA level of 8-30 ng/ml.
在印度尼西亚，前列腺特异性抗原（PSA）和PSA密度（PSAD）值被发现显著高于西方国家公认的正常水平。然而，在PSA值为4 - 10 ng/ml时，PSA大于10 ng/ml且PSAD高于0.15仍提示需进行前列腺活检。鉴于我国前列腺癌发病率较低，这种情况导致了不必要的活检。我们的目的是寻找能提高前列腺癌检测特异性和敏感性的血清PSA水平及PSAD临界值。这项回顾性横断面研究纳入了1994年至1997年期间在苏伯瓦拉斯医院（SWH）和西托·曼古库苏莫医院（CMH）连续就诊的805例40至95岁患者。所有患者均接受了直肠指检（DRE）和经直肠超声检查（TRUS）以测量前列腺体积。在测定血清PSA水平并计算PSAD后，如果PSA水平大于10 ng/ml或在PSA值为4 - 10 ng/ml时PSAD大于0.15，则进行前列腺活检。使用单因素分析评估PSA、中间PSA水平和PSAD提高前列腺癌检测准确性的能力。在805例患者中，240例患者PSA水平<4 ng/ml，230例患者PSA水平为4 - 10 ng/ml，335例患者PSA水平>10 ng/ml。在230例中间PSA水平的患者中，108例PSAD>0.15。35例患者经组织学确诊为前列腺癌，即PSA值为4 - 10 ng/ml且PSAD>0.15的108例患者中有3例，PSA>10 ng/ml的335例患者中有32例。这些组中有105例和303例不必要的活检。当PSA临界值≥8 ng/ml时，我们发现对前列腺癌的敏感性为100%。在PSA水平为8 - 30 ng/ml时，PSAD≥0.20对前列腺癌的敏感性为100%。使用这些新的临界值可节省148例活检（33.4%）。我们从这项研究得出结论，血清PSA水平和PSAD的公认值导致了我们患者中许多不必要的活检。相反，进行前列腺活检最敏感的临界值是血清PSA水平大于8.0 ng/ml，以及在血清PSA中间水平为8 - 30 ng/ml时PSAD大于0.20。
