Evaluation of pT2 subdivisions in the TNM staging system for prostate cancer

To evaluate the subclassifications of pT2 diseases in tumour-nodes-metastases (TNM) staging system for prostate cancer.

We retrospectively analysed the data of 372 patients who underwent radical retropubic prostatectomy (RRP) for pathologically organ-confined prostate cancer at our institution. Pathological staging of all subjects were re-evaluated using the 1997 and the 2002 TNM staging system for prostate cancer. Various clinicopathological features along with biochemical recurrence-free survival (BRFS) of pT2 subgroups were assessed.

Using the 2002 TNM staging criteria, 87 of the tumours (23.4%) were pT2a, and 284 (76.3%) were pT2c. Of all subjects, there was only one (0.3%) pathological 2002 T2b tumour identified. When subjects were classified according to the 1997 versions of the T2 subclassification (pT2a vs pT2b), the 1997 pT2a and pT2b cases showed no significant difference regarding BRFS (log-rank P = 0.645) among those who were followed-up for >2 years after RRP. Also, pathological stage (1997 pT2a vs pT2b) was not a significant predictor of BRFS in either uni- or multivariate analysis (P = 0.289 and P = 0.241, respectively). Only preoperative serum PSA level and pathological Gleason score along with positive surgical margin were significant predictors of PSA outcome after RRP on multivariate analysis.

Our results suggest that two- or three-tiered subclassification of pT2 organ-confined prostate cancer via methods used in the previous or current TNM staging system may not be appropriate. Efforts should be made to upgrade the current TNM staging system for prostate cancer.