Background. The aims of this study were to identify prognostic factors of patients with submucosa-invasive (T1b) gastric cancer and to verify the validity of adjuvant chemotherapy for this disease.
Methods. We retrospectively examined the cases of 1,236 consecutive patients in our prospectively maintained database with T1b gastric cancer who underwent gastrectomy in 1995-2012. We used 11 clinicopathologic characteristics to identify prognostic factors by univariate and multivariate analyses. We compared the survival of the 160 node-positive T1b gastric cancer patients with that of 133 patients in the same database who had node-positive muscularis propria-invasive (T2) gastric cancer and had undergone gastrectomy without adjuvant chemotherapy during the same period, as a reference cohort.
Results. The 5-year overall survival rate was 91.4% for all 1,236 patients. Advanced age (hazard ratio [HR] 4.51; 95% confidence interval [CI] 3.26-6.24; P < .01), male sex (HR 2.26; 95% CI 1.5- 3.26; P < .01), and the presence of lymph node metastasis (HR 1.89; 95% CI 1.33-2.70; P < .01) were independent prognostic factors. The 5-year overall survival rates were 92.5 % in node-negative patients, 84.5% in patients with 1 or 2 metastatic nodes, and 80.1% in patients with 3 or more metastatic nodes (P <.01). The 5-year overall survival rates of the node-positive T1b and T2 gastric cancer patients were 83.6% and 81.2%, respectively (P = .73).
Conclusion. The prognosis of node-positive T1b gastric cancer patients after curative gastrectomy was unsatisfactory. Adjuvant chemotherapy should be considered for these patients, especially those with 3 or more metastatic nodes.