Prognostic stratification of ampullary cancer according to the 8th edition of the AJCC classification (2017)

(A) Significant differences in OS were found between T1 and T2 (p = 0.0499) and T3a and T3b (p = 0.0189), but not between T1b and T2 (p = 0.6286) or T2 and T3a (p = 0.8889). Significant differences in RFS were found between T1a and T1b (p = 0.0030), but not between T1b and T2 (p = 0.9313), T2 and T3a (p = 0.0732), or T3a and T3b (p = 0.2118).
(B) Significant differences in OS were found between N0 and N1 (p <0.0001), but not between N1 and N2 (p = 0.2811). Significant differences in RFS were found between N0 and N1 (p <0.0001) and N1 and N2 (p = 0.0259).
(C) Significant differences in OS were not found in any intergroup; however, significant differences in RFS were found between stages IA and IB (p = 0.0175), but not between the other subgroups.