Smeltzer MP, et al. - This study investigated if survival was affected by sequentially more stringent definitions of pN staging quality in a cohort of patients with non–small cell lung cancer (NSCLC) after resection with curative intent. Findings showed that prognostic value of pN stratification depended on the thoroughness of examination. Furthermore, a large proportion of intercontinental survival differences may be explained by variations in thoroughness of nodal staging. In order to improve the prognostic value of the TNM staging system, more thorough nodal examination practice must be disseminated.