Publications

Abstract

Introduction Anterior located tumors are estimated to constitute 20% of all prostate cancers. Current data indicates that trans-perineal (TP) biopsies are more reliable than trans-rectal (TR) biopsies in identifying these tumors. If correct, then this superior reliability should be reflected in the actual proportion of anterior tumors identified by TP biopsies compared to TR biopsies. This study investigated this hypothesis with reference to prostatectomy specimens. Methods Histopathology records of patients who underwent radical prostatectomy between 2004-2010 were examined. Patients were grouped into two categories: 1. Cancers identified by primary TP biopsy 2. Cancers detected by TR biopsy. After grouping, the location and size of the main tumor was recorded. From this, the proportion of anterior located tumors was determined. Results 1132 radical prostatectomy specimens were examined. 414 cancers were detected by TP and 718 by TR. For TP, 67 (16.2%) of cancers were anterior only compared to 86 (12%) for TR (p=0.046). TP also identified tumors at a smaller size (1.4 cm3) compared to TR (2.1 cm3) (p=0.03). TP detected tumors were also more likely to be organ confined, with extra-capsular extension (ECE) present in 13% of TP compared to 27% of TR specimens (p=0.045). Conclusion Primary trans-perineal biopsy of the prostate detects more anteriorly located cancers compared to trans-rectal biopsy (16.2% vs 12%). It also identifies them at a smaller size and stage compared. This implies that trans-rectal biopsy can miss significant anterior cancers or can only identify them at a more advanced stage compared to TP biopsy.