Subclassification of pathologically organ-confined (pT2) prostate cancer does not significantly predict postoperative outcomes in Korean males

Purpose: We evaluated the prognostic association of pT2 subclassification with the oncological outcomes in patients with prostate cancer (PCa) who underwent radical prostatectomy (RP) in South Korea.

Materials and methods: We retrospectively reviewed 3,529 patients who underwent RP for pathologically organ-confined PCa between 2003 and 2017 at Seoul National University Bundang Hospital. We analyzed the differences in the rates of biochemical recurrence (BCR), overall survival (OS), and cancer-specific survival (CSS) between pT2 substages.

Results: According to the 2002 TNM staging system, 362 (15.3%) and 2,000 patients (84.5%) had T2a (involving one-half or less of a unilateral lobe) and T2c (involving bilateral lobes) diseases. Four patients (0.2%) had T2b (involving more than one-half of a unilateral lobe) disease and none of them developed BCR. The mean follow-up period was 8.4±3.7 years and 175 patients (7.4%) had BCR. On multivariable analysis, pT2 subclassification (pT2a/b vs. pT2c) was not a significant predictor of BCR (p=0.224) or OS (p=0.311). Biochemical disease-free survival (p=0.091), OS (p=0.502), and CSS (p=0.063) showed no significant difference between pT2 substages.

Conclusions: Our study revealed that the pT2 subclassification of PCa in Korean males provided no value for predicting BCR, OS, and CSS after RP, which agrees with recently reported results based on the updated 8th version of the American Joint Committee on Cancer (AJCC) TNM staging system.