Examining more than 35 lymph nodes improves the staging and survival in resectable advanced gastric cancer: a multi-institutional study in China.

PURPOSE

More examined lymph nodes (ELN) are correlated with better staging and a better prognosis of gastric cancer, although the optimal number of ELNs remains under dispute. This study explored the optimal number of ELNs for resectable advanced gastric cancer (AGC).

METHODS

Clinicopathological characteristics and survival data of 4739 AGC patients were collected from 3 GC centers in China. The series of odds ratios (ORs) for negative-to-positive node stage migration and hazard ratios (HRs) for the disease-specific survival with more ELNs were fitted using locally weighted scatterplot smoothing (LOWESS). The structural breakpoints were determined using the Chow test. A Kaplan-Meier survival analysis was used to validate the cutoff ELN count.

RESULTS

With increasing numbers of ELNs, the cohort exhibited significant proportional increases in stage migration (OR = 1.006, p = 0.024) and serial improvements in survival (HR = 0.979, p < 0.001) per additional ELN after adjusting for covariates. The optimal ELN count was identified as 36, which was further validated with good discrimination for survival stratification in an external cohort that included 5796 patients from the SEER database.

CONCLUSION

Having more than 35 LNs to examine could achieve more accurate staging and a better survival for AGC patients with stage N0-N2 disease.