Stage migration influences on stage-specific survival comparison between D1 and D3 gastric cancer surgeries

Aims We evaluate the influency stage migration in a randomised trial comparing D1 (N 1 lymphadenectomy) and D3 (N 1, 2 and 3 lymphadenectomy) dissections. Methods Two hundred and thirteen curatively resected patients were analysed, with this TNM data. Results After applying D3 patientsʹ data according to simulated D1 staging, D3 resections were associated with up-staging to N2-3 levels in 8% of patients according to the N stage. The likelihood of N-status migration increased with increasing depth of invasion into the gastric wall. The increases in the calculated survival rate after stage migration on known 5-year survival rates were: 2% in stage IB, 1% in stage II, 4% in stage IIIA, and 1% in stage IIIB. Conclusions Stage migration secondary to meticulous lymph node dissection affects stage-specific survival rates. True therapeutic survival benefit of D3 resection can only be assessed in this context.