Evaluation of pT 0 prostate cancer in patients undergoing radical prostatectomy

Objective To evaluate the incidence, predictors and oncological outcomes of pT 0 prostate cancer ( PC a). Methods We conducted a retrospective analysis of 20 222 patients undergoing radical prostatectomy ( RP ) for PC a at the Mayo Clinic between 1987 and 2012. Disease recurrence was defined as follow‐up PSA >0.4 ng/mL or biopsy‐proven local recurrence. Systemic progression was defined as development of metastatic disease on imaging. Comparisons of baseline characteristics between pT 0 and non‐ pT 0 groups were carried out using chi‐squared tests. Recurrence‐free survival was estimated using the Kaplan–Meier method and compared using the log‐rank test. Results A total of 62 patients (0.3%) had pT 0 disease according to the RP specimen. In univariable analysis, pT 0 disease was significantly associated with older age ( P = 0.045), lower prostate‐specific antigen ( PSA ; P = 0.002), lower clinical stage ( P < 0.001), lower biopsy Gleason score ( P = 0.042), and receipt of preoperative transurethral resection, hormonal and radiation therapies (all P < 0.001). In multivariable analysis, lower PSA levels, lower Gleason score, and receipt of preoperative treatment were independently associated with pT 0 (all P < 0.05). Seven patients (11%) with pT 0 PC a developed disease recurrence over a median follow‐up of 10.9 years. All seven patients had preoperative treatment(s) and three had recurrence with a PSA doubling time of <9 months. Compared with non‐ pT 0 disease, pT 0 disease was associated with longer recurrence‐free survival ( P < 0.05). Only one (1.6%) patient with pT 0 disease developed systemic progression. Conclusions pT 0 stage PC a is a rare phenomenon and is associated with receipt of preoperative treatment and features of low‐risk PC a. Although pT 0 has a very favourable prognosis, some men, especially those who received preoperative treatment, experience a small but non‐negligible risk of disease recurrence and systemic progression.