Background/aims: Little is known about the clinicopathological features of intermediate-stage T2 gastric cancer, defined as tumors invading the muscularis propria or subserosa.
Methodology: Of 808 patients with gastric cancer, 210 patients (25.9%) who underwent gastrectomy for T2 gastric cancer were selected for this retrospective study. The clinicopathologic findings of these patients were analyzed retrospectively from their hospital records.
Results: Of all 808 patients with gastric cancer, 73 patients (9.0%) had tumors invading the muscularis propria (mp). The remaining 137 patients (16.9%) had tumors invading the subserosa (ss). Compared with ss gastric cancer, mp gastric cancer was associated with smaller tumor size, an absence of lymphatic spreading, and hematogenous and late recurrence [disease-free interval: 654.5 days (mp) vs. 365.5 days (ss)]. Univariate analysis of cases with curative operations showed that lymphatic invasion, and lymph node metastasis were significant prognostic factors in patients with T2 gastric cancer. Further examination by multivariate analysis demonstrated that pN2 or higher as classified by both the JCGC (Japanese Classification of Gastric Cancer) and the TNM lymph node staging systems was a predictor of poor prognosis.
Conclusions: JCGC and TNM lymph node staging systems were the most reliable prognostic factors for T2 gastric cancer. Close follow-up should be required for patients with stage pN2 or higher gastric cancer. Long-term follow-up should be required for mp cancers, in particular.