Crawford E D, Hirano D, Werahera P N, Lucia M S, DeAntoni E P, Daneshgari F, Brawn P N, Speights V O, Stewart J S, Miller G J
Department of Pathology, University of Colorado Health Sciences Center, Denver, USA.
J Urol. 1998 Apr;159(4):1260-4. doi: 10.1016/s0022-5347(01)63576-6.
Sampling error is an inherent problem of prostate biopsy, and the determination of clinical significance based on biopsy results is problematic. We quantify the dimensions of these problems by computer simulation.
We constructed 3-dimensional solid computer models of 59 autopsy prostates containing clinically undetected prostate cancer, and performed simulations of the standard prostate biopsy method.
Biopsy simulation detected 19 tumors from the 59 prostates, the majority of which were in the most accessible portion of the prostate, the posterior peripheral zone. Using 0.5 cc or greater tumor volume or less than 0.5 cc and Gleason sum 7 or greater as criteria of significance, the model detected 58% (11 of 19) significant tumors and 20% (8 of 40) insignificant tumors. With 0.25 cc or greater tumor volume or less than 0.25 cc and Gleason sum 7 or greater as criteria 15 of 29 significant (52%) and 4 of 30 insignificant (13%) tumors were detected. Among significant tumors defined by either volume criterion there was a statistical difference between detected and undetected tumors in terms of mean tumor volume and mean ratio of tumor volume-to-prostate volume. Among insignificant tumors defined by either criterion there was no such difference.
As much as 20 to 40% of currently detected prostate cancer may be histologically insignificant, as 4 of 19 cancers were detected when 0.25 cc was used as volume determinant of clinical significance and 8 of 19 were detected when 0.5 cc volume was used. These tumors are detected randomly. On the other hand, perhaps only one-half to three-fourths of clinically significant prostate cancers are being detected, and then only because the volume and anatomic location make them hard to miss.
抽样误差是前列腺活检固有的问题，基于活检结果确定临床意义存在问题。我们通过计算机模拟对这些问题的程度进行量化。
我们构建了59个含有临床未检测出前列腺癌的尸检前列腺三维实体计算机模型，并对标准前列腺活检方法进行模拟。
活检模拟从59个前列腺中检测出19个肿瘤，其中大多数位于前列腺最易触及的部位，即外周带后部。以肿瘤体积0.5 cc或更大或小于0.5 cc且Gleason评分7或更高作为有意义的标准，该模型检测出58%（19个中的11个）有意义的肿瘤和20%（40个中的8个）无意义的肿瘤。以肿瘤体积0.25 cc或更大或小于0.25 cc且Gleason评分7或更高作为标准，检测出29个有意义肿瘤中的15个（52%）和30个无意义肿瘤中的4个（13%）。在由任一体积标准定义的有意义肿瘤中，检测出的和未检测出的肿瘤在平均肿瘤体积以及肿瘤体积与前列腺体积的平均比值方面存在统计学差异。在由任一标准定义的无意义肿瘤中则不存在这种差异。
目前检测出的前列腺癌中，多达20%至40%在组织学上可能无意义，因为以0.25 cc作为临床意义的体积判定标准时，19个癌症中检测出4个，以体积0.5 cc作为标准时检测出19个中的8个。这些肿瘤是随机检测出的。另一方面，或许仅检测出了临床有意义的前列腺癌的二分之一至四分之三，而且只是因为其体积和解剖位置使其难以漏检。
