Should pathologists continue to use the current pT2 substaging system for reporting of radical prostatectomy specimens?

OBJECTIVES

Pathologic staging tries to maintain symmetry with clinical staging, allowing a direct comparison of both. However, in contrast to clinical substaging of T2 prostate cancers, is controversial whether pathologic T2 substaging conveys prognostic information. The aim of our study is to analyze the clinicopathologic findings and the prognostic information comparing the clinical with the pathological T2 substaging of patients submitted to radical prostatectomy.

MATERIALS AND METHODS

Using the 2009 TNM staging system, 169 patients with clinical stage T2a were compared with patients with stage T2b/T2c, and 142 patients with pathological stage T2a were compared with patients with stage T2c. All surgical specimens were step-sectioned. Using a semiquantitative point-count method for tumor extent evaluation, all insignificant tumors were excluded from analysis. Clinicopathological characteristics were compared between the groups. Biochemical recurrence data were compared using log-rank analysis, and significant predictors of time to biochemical recurrence were determined using univariate and multivariate Cox proportional hazards model.

RESULTS

There was significant difference in biochemical recurrence rates between men with clinical T2a versus T2b/T2c tumors but no difference between men with pathological T2a versus T2c tumors. No patient in pathologic stage T2b was found. On multivariate analysis, clinical stage T2b/T2c was independent predictor of time to biochemical recurrence following surgery but not pathological stage T2c.

CONCLUSIONS

There is lack of symmetry between clinical and pathological T2 substaging as predictors of time to biochemical recurrence following surgery. The findings support a reevaluation of the TNM pathologic T2 stage, which should not be substratified.