Clinicopathologic characteristics and prognostic value of various histological types in advanced gastric cancer

The prognostic value of histological types in gastric cancer is not well defined. This study aims to clarify the clinicopathologic features of various WHO histological types and their prognostic significance in advanced gastric cancer (AGC). We retrospectively reviewed 741 patients with gastric cancer in our hospital from 1997 to 2007. The AGC (741 cases) were divided into five histological types: well-differentiated carcinoma (WD), moderately differentiated carcinoma (MD), poorly differentiated carcinoma (PD), mucinous carcinoma (MC), and signet ring cell carcinoma (SRC). The various AGC histological types presented significant differences in their clinical and tumor features. The five-year survival rates of patients with WD, MD, PD, MC, and SRC were 87.1%, 57.1%, 50.6%, 62.7%, and 43.4%, respectively (P=0.012). Multivariate analysis showed that cell differentiation, age, depth of invasion, and lymph node metastasis were independent prognostic factors in AGC, whereas MC and SRC were not. Cell differentiation is related to tumor aggression or patient stage. Advanced stage SRC carcinoma had more aggressive features and worse prognosis than the other types. MC carcinoma survival is correlated with the stage at diagnosis. The degree of cell differentiation is an important predictor of survival in AGC.