ObjectiveThe aim of this study was to investigate the value of 8th American Joint Committee on Cancer (AJCC) anatomic and prognostic stage groups for penile cancer patients and explore whether there is room for improvement. MethodsThe clinical and histopathologic data from 16 centers between 2000 and 2021 were assessed according to the 8th AJCC anatomic and prognostic stage groups. Kaplan–Meier plots were used to estimate the disease-specific survival (DSS) of the patients. The accuracy of the staging systems was investigated using the Harrell's concordance index (C-index). ResultsThe 5-year DSS rates for patients with stages 0is/a, I, IIA, IIB, IIIA, IIIB, and IV (stage 0 to stage IV) disease were 100 %, 98.9 %, 85.5 %, 81.1 %, 65.8 %, 34.4 %, and 23.2 %, respectively (p0is/a–I=0.798, pI–IIA<0.001, pIIA–IIB=0.486, pIIB–IIIA<0.001, pIIIA–IIIB<0.001, pIIIB–IV=0.004, ptotal<0.001). According to the modified model 1 system, the 5-year DSS rates without survivorship overlap for patients with stages 0is/a, I, II, IIIA, IIIB, and IV disease were 100 %, 98.9 %, 87.8 %, 65.8 %, 34.4 %, and 23.2 %, respectively (p0is/a–I=0.798, pI–II<0.001, pII–IIIA=0.002, pIIIA–IIIB<0.001, pIIIB–IV=0.004, ptotal<0.001). Similarly, according to the modified model 2 system, the 5-year DSS rates without survivorship overlap for patients with stages 0is/a, I, II, IIIA, IIIB, and IV disease were 100 %, 99.0 %, 85.8 %, 65.8 %, 34.4 %, and 23.2 %, respectively (p0is/a–I=0.757, pI–II<0.001, pII–IIIA=0.008, pIIIA–IIIB<0.001, pIIIB–IV=0.004, ptotal<0.001). The C-index of the simple modified staging systems were not inferior to those of the AJCC anatomic and prognostic stage groups. These results were confirmed by the bootstrap internal validation. ConclusionThere is still room for improvement about 8th AJCC anatomic and prognostic stage groups. The improved models, which are more concise and convenient, had a similar predictive value.
Read full abstract