Pathologic stage T2a and T2b prostate cancer in the recent prostate-specific antigen era: Implications for unilateral ablative therapy

BACKGROUND. Early detection of small volume prostate cancer (PCa) has led to the concept of focal therapy to treat in an organ-sparing manner. We evaluated trends in pathologic staging among patients with localized PCa undergoing radical prostatectomy (RP), defining the frequency of unilateral cancers during 1988-1995, 1996-2000 and 2001-2006. METHODS. Data were abstracted from the Duke Prostate Cancer Outcome database selecting 3,676 men with available pathology treated with RP. Based on surgical pathology, trends in as pathological T (pT) stage, pathological Gleason Score (pGS), and percent tumor involvement (PTI) were evaluated. RESULTS. pT2a increased from 2.8% of men undergoing RP in 1988-1995 to 13.0% during 2001-2006 (P < 0.0005). PTI analysis shifted towards low volume disease, e.g. PTI <= 5% increased from 10% during 1988-1995, to 37% in 2001-2006 (P < 0.005). Of all pT2a disease throughout 1988-2006, an increase in proportion of pT2a tumors from 10% during 1988-1995 to 69.4% during 2001-2006 was identified. Over three eras, pT2a had minimal (65% had PTI <= 5%) or small volume (14% had PTI 5.01-10.00) disease, and 59% were low grade (pGS <= 6). Using a Cox Hazard model, pT2a versus pT2b disease, surgical margins, PTI, and PSA statistically contributed to PSA disease-free survival in the contemporary era 2001-2006. CONCLUSIONS. The increasing prevalence Of unilateral pT2a/T2b PCa characterizes a growing proportion of men recently electing RP. These tumors are associated with lower PTI, pGS <= 7, and demonstrated better PSA-free survival in the 2001-2006 era. These low risk pathologic characteristics may allow for unilateral focal therapy in carefully selected patients.