Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Kaplan-Meier curves for overall survival according to American Joint Committee on Cancer N categories (A) and Nr categories (B). A: No significantly survival difference was observed for N2 vs N3 category (P = 0.159); B: The survival differences were significant in all subgroups analysis (P < 0.001).
