Comparison of Prognostic Performance of 8th and 7th Edition of AJCC Staging System for Patients With Gallbladder...

We compared the predictive performance of the 7th and 8th editions of the AJCC staging systems in stratifying disease-related survival outcomes in patients with GBC undergoing curative intent surgery.

Patients that underwent curative intent surgery for GBC at our institution (2014 and 2021) were included in the study. Various clinico-pathological data were extracted to perform Kaplan-Meier survival analysis.

A total of 240 patients were included in the study. Both, TNM-7, and TNM-8 staging systems can stratify patients into stages with statistically significant differences in disease-free and overall survival. Survival rates drop with stage progression. Using TNM-8, 8/240 (3.33%) patients were upstaged from Stage IIIB (TNM-7) to IVB (TNM-8) and 12/240 (5%) were down-staged from Stage IVB(TNM-7) to IIIB(TNM-8). Survival curves of the re-classified patients matched those of the corresponding TNM-8 stage. Additionally, there was statistically significant difference in their survival (p < 0.001) compared to their corresponding TNM-7 stage. There was no statistically significant difference in survival rates between stages IIA, IIB (TNM-8), and stage II (TNM-7). However, stage IIA had a slightly better survival than stage IIB.

Though both TNM-7 and TNM-8 are useful for stratifying patients with GBC, TNM-8 has a better prognostic performance than TNM-7.