Catalona W J, Beiser J A, Smith D S
Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Urol. 1997 Dec;158(6):2162-7. doi: 10.1016/s0022-5347(01)68187-4.
We examined the usefulness of measurements of free prostate specific antigen (PSA) and PSA density for predicting prostate cancer in men who had had a prior negative biopsy, a serum PSA level of 4.1 to 10.0 ng./ml. and benign findings on prostate examination.
We measured percent free serum PSA and PSA density in 163 male volunteers age 50 years or older who were advised to have repeat prostatic biopsies for a serum PSA level of 4.1 to 10.0 ng./ml.
Of 99 men who had repeat biopsies 20 (20%) had prostate cancer detected. Prostate cancer was significantly associated with lower free PSA level and higher PSA density, with overlap in 83% of the cases. The use of percent free PSA cutoffs of 28 and 30% would have detected 90 and 95% of cancers, respectively, and avoided 13 and 12% of the biopsies, respectively. PSA density cutoffs of 0.10 and 0.08 would have detected 90 and 95% of cancers, respectively, and avoided 31 and 12% of biopsies, respectively.
Free PSA and PSA density predict prostate cancer in men who have had prior negative prostatic biopsies, serum PSA levels of 4.1 to 10.0 ng./ml. and a benign prostate examination. Both parameters may be used to avoid unnecessary biopsies with an acceptable decrease in sensitivity. Further studies are needed to determine cutoffs to be used in clinical practice.
我们研究了游离前列腺特异性抗原（PSA）测量值和PSA密度在预测曾有过阴性活检、血清PSA水平为4.1至10.0 ng/ml且前列腺检查结果为良性的男性患前列腺癌方面的实用性。
我们测量了163名年龄在50岁及以上的男性志愿者的血清游离PSA百分比和PSA密度，这些志愿者因血清PSA水平为4.1至10.0 ng/ml而被建议进行重复前列腺活检。
在99名接受重复活检的男性中，有20名（20%）检测出患有前列腺癌。前列腺癌与较低的游离PSA水平和较高的PSA密度显著相关，83%的病例存在重叠。使用游离PSA百分比临界值28%和30%分别可检测出90%和95%的癌症，并分别避免13%和12%的活检。PSA密度临界值0.10和0.08分别可检测出90%和95%的癌症，并分别避免31%和12%的活检。
游离PSA和PSA密度可预测曾有过阴性前列腺活检、血清PSA水平为4.1至10.0 ng/ml且前列腺检查结果为良性的男性患前列腺癌的情况。这两个参数均可用于避免不必要的活检，同时灵敏度下降在可接受范围内。需要进一步研究以确定临床实践中使用的临界值。
