The impact of N-ratio in minimizing stage migration phenomenon in gastric cancer patients with insufficient number or level of lymph node retrieved: results from a Chinese mono-institutional study in 2159 patients.

Background: Previous studies indicate that N-ratio has significant superiority in minimizing ‘stage migration’ for patients with >15 lymph nodes retrieved. Whether the result is applicable to patients with ≤15 lymph nodes retrieved is still in question. Patients and methods: Overall survival rates of 2159 gastric cancer patients who underwent radical resection were compared between patients with different number and level of lymph nodes retrieved according to pN [International Union Against Cancer (Union Internationale Contre le Cancer)/AJCC N stage], n (JGCA N stage) and rN (N-ratio) staging system. Results: Patient number was significantly different between insufficient and sufficient number or level retrieved group in pN and n system, respectively, but not in rN system, while overall survival rates were not significantly different between those groups. The 5-year survival rates of patients with insufficient nodes retrieved were significantly lower than those with sufficient nodes retrieved in pN and n system, but not in rN system. The hazard risk for patients with insufficient nodes retrieved was significantly higher than that for patients with sufficient nodes retrieved in pN and n system, but not in rN system. Conclusion: The rN stage has more potential advantages in minimizing stage migration phenomenon for patients with insufficient number or level of lymph nodes retrieved. [ABSTRACT FROM AUTHOR]