The clinical features of anterior prostate cancers.

OBJECTIVE: To identify the clinical characteristics of anterior prostate cancers (APCs) and to compare these with posterior prostate cancers (PPCs). PATIENTS AND METHODS: We reviewed 1290 consecutive open and laparoscopic radical prostatectomies (RPs) at the authors' institution from January 2000 to March 2004. Prostates were processed using a whole-mount technique. Each surgical specimen was reviewed by one pathologist, and tumour areas were marked, measured and mapped. Positive surgical margins (PSMs) were defined as the presence of cancer cells at the inked surface of the specimen. Specimens were then categorized by the location of their dominant tumour, i.e. pure anterior, anterior > posterior, posterior > anterior, or pure posterior. We compared the clinical and pathological characteristics of 259 patients in the pure-anterior group with the 594 in the pure-posterior group.
RESULTS: Before RP, APCs had a significantly lower biopsy Gleason score (78% vs 68% with Gleason 4-6), fewer mean biopsy cores positive (2.0 vs 2.6), a smaller median percentage of positive cores (17% vs 26%), lower clinical stage (T1 in 79% vs 62%), and higher progression-free probability estimated by preoperative nomogram (86% vs 84%) than PPCs. Patients with APCs also had more previous negative biopsy sessions. The pathological analysis of RP specimens showed that those with APCs had higher tumour volume (1.6 vs 0.83 mL) and had a higher PSM rate (12% vs 7%) than those with PPCs, despite specimens with PPCs having higher rates of extraprostatic extension (10% vs 19%).
CONCLUSIONS: APCs have lower Gleason grade and lower rates of extraprostatic extension, yet patients with anterior tumours have higher overall tumour volumes and higher PSM rates. Because current tools for detecting and staging prostate cancer can underestimate the extent of anterior prostate disease, improved methods are needed for localizing and characterizing anterior cancers.