Extent of extraprostatic extension independently influences biochemical recurrence-free survival: evidence for further pT3 subclassification.

Abstract

To evaluate the impact of the extent of extraprostatic extension (EPE) on biochemical recurrence-free survival (BCRFS) after radical prostatectomy (RP). We queried our RP database from 2004 to 2013. Extent of EPE on RP was divided into 3 groups: no EPE, focal EPE (F-EPE; a few extraprostatic cancer glands on 1-2 slides), and nonfocal EPE (NF-EPE). Multivariate Cox proportional hazard models determined the influence of EPE on BCRFS. A total of 10,750 men underwent RP during the study period. Of these, 7843 men (73.0%) had no EPE, 1258 (11.7%) men had F-EPE, and 1649 men had (15.3%) NF-EPE. Overall BCRFS was worse in men with NF-EPE than those with F-EPE or no EPE. In a multivariate model, F-EPE and NF-EPE were both independently associated with worse BCRFS compared with no EPE (F-EPE: hazard ratio, 2.41; 95% confidence interval, 1.84-3.10; P <.0001; NF-EPE: hazard ratio, 3.57; 95% confidence interval, 2.89-4.40; P <.0001). When stratified by Gleason score in men without seminal vesicle invasion or lymph node metastases, there was no difference in BCRFS for Gleason score <6, 3 + 4 = 7, 4 + 3 = 7, and 8 for F-EPE vs no EPE; however, patients with Gleason score of 9-10 with F-EPE had worse BCRFS. Patients with NF-EPE had significantly worse BCRFS for Gleason score <6, 7, and 8 and a trend for worse BCRFS for Gleason score 9-10 compared with no EPE. Although all men with EPE have higher BCRFS after RP, men with NF-EPE have worse BCRFS than those with F-EPE, supporting the need to substratify pT3a prostate cancer in the American Joint Committee on Cancer staging system.