Background: The TNM staging system for localized prostate cancer (PCa) divides tumors based on clinical parameters into a clinical (c)T category and, after radical prostatectomy (RP), a pathological (p)T category.
Objectives: This study examines the extent to which the cT and the pT category correspond to each other and whether the two categories differ in their prediction for organ-confined disease.
Patients and methods: Data of 687 RP patients were collected in a prospective, noninterventional, multicenter health service research study for the treatment of localized PCa (HAROW). Group comparisons were performed by analysis of variance and student t‑test as well as the chi-squared test or the Fisher exact test.
Results: Clinical cT1 category (62.9%) and pathological pT2c category (56.6%) were diagnosed most frequently. The correspondence of cT and pT category was 15% for cT2a , 10.5% for cT2b, and 55% for cT2c. An extraprostatic extension (≥pT3) was observed for the categories cT1 and cT2 in 23.5% and 36.4% (p < 0.001), differences in the subcategories cT2a-c were not significant: cT2a = 28.8%, cT2b = 42.1%, and cT2c = 38.8% (p = 0.194). Tumors with a pathologically extraprostatic extension were not recognized clinically in >50%.
Conclusions: For localized PCa there is low agreement between clinical and pathologic T category, thus, often leading to understaging. An adaptation of the T classification of the TNM system with division into "not palpable" and "palpable" appears sufficient for a prognostic prediction.
Keywords: Digital rectal examination; HAROW-Study; Health service research; Prostate cancer; TNM-staging system.