UICC and AJCC 8th edition tumor-nodes-metastasis (TNM) classifications for patients treated with radical prostatectomy: reliable but not infallible prognostic tools

We read with interest the article by Herden and colleagues (1) regarding the validation of the UICC and AJCC 8th edition tumor-nodes-metastasis (TNM) system on a German community-based dataset. In this study, the authors analyzed data derived from the HAROW study (n=2,957), a prospective, non-interventional, health service research study examining various treatment options for patients with localized prostate cancer (≤ cT2c). Within their study, Herden and colleagues selected all patients that underwent radical prostatectomy (RP) (n=1,738, 58.8%) with available pathologic information and follow-up data (n=515). For validation purpose, the authors stratified the patients in either cT1 or cT2, S I (≤ T2a) or S II (T2b/c), and prognostic stage group (PSG) I, PSG IIA, PSG IIB or PSG ≥ IIC according to the TNM classification and World Health Organization (WHO) grading. All groups were compared regarding proportion of organ confined disease (≤ pT2) and extraprostatic extension (≥ pT3) after RP, as well as favorable (≤2) and unfavorable (≥3) WHO grade group, or favorable (≤7a) and unfavorable (≥7b) Gleason Score after RP, respectively. Finally, biochemical recurrence free-survival (BFS) was examined and compared between groups in each classification systems