Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
J Urol. 2012 Feb;187(2):477-80. doi: 10.1016/j.juro.2011.10.042. Epub 2011 Dec 15.
Several radical prostatectomy series have linked small prostates with high grade cancer based on the hypothesis that a small prostate results from a low androgen milieu that selects for less hormone dependent, more aggressive tumors. We previously reported that this association resulted from ascertainment bias from the performance characteristics of prostate specific antigen rather than from tumor biology in our radical prostatectomy cohort. In this study we analyzed this association in a more generalized population of men who underwent prostate needle biopsy.
The prostate needle biopsy database at our institution was queried for all initial biopsies. Included patient characteristics were age, race, family history of prostate cancer, prostate specific antigen, abnormal digital rectal examination and prostate volume in ml on transrectal ultrasound. Multivariate logistic regression was used to determine the influence of prostate volume on the odds of high grade cancer.
The study population included 1,295 patients during 2000 to 2010, of whom 582 (44.9%) had prostate cancer and 398 (30.7%) had high grade cancer. When all patients were pooled, the OR for high grade cancer was 0.85 (95% CI 0.78-0.92) for each 10 ml increase in prostate volume. When patients were divided by clinical T stage, the corresponding ORs for those with T1c disease was 0.83 (95% CI 0.74-0.93) and for those with T2 or greater disease it was 0.99 (0.98-1.00).
The association between small prostates and high grade cancer exists only in men with clinical T1c (normal digital rectal examination) prostate cancer. It likely resulted from ascertainment bias due to the performance characteristics of prostate specific antigen rather than tumor biology.
几项前列腺切除术系列研究基于这样一种假设，即小前列腺与高级别癌症有关，即小前列腺是由低雄激素环境引起的，这种环境选择了依赖性较低、侵袭性更强的肿瘤。我们之前报道称，这种关联是由于前列腺特异性抗原（PSA）的性能特征而不是前列腺切除术队列中的肿瘤生物学导致的检出偏倚。在这项研究中，我们在接受前列腺穿刺活检的更广泛人群中分析了这种关联。
我们机构的前列腺穿刺活检数据库中查询了所有初次活检的患者。纳入的患者特征包括年龄、种族、前列腺癌家族史、前列腺特异性抗原、异常直肠指检和经直肠超声测量的前列腺体积（ml）。多变量逻辑回归用于确定前列腺体积对高级别癌症的可能性的影响。
研究人群包括 2000 年至 2010 年间的 1295 例患者，其中 582 例（44.9%）患有前列腺癌，398 例（30.7%）患有高级别癌症。当所有患者被汇总时，前列腺体积每增加 10ml，高级别癌症的比值比（OR）为 0.85（95%CI 0.78-0.92）。当按临床 T 分期将患者分组时，T1c 疾病患者的相应 OR 为 0.83（95%CI 0.74-0.93），T2 或更高级别疾病患者的 OR 为 0.99（0.98-1.00）。
小前列腺与高级别癌症之间的关联仅存在于临床 T1c（正常直肠指检）前列腺癌患者中。这可能是由于前列腺特异性抗原的性能特征导致的检出偏倚，而不是肿瘤生物学。
