Impact of tumor infiltration pattern into the surrounding tissue on prognosis of the subserosal gastric cancer (pT2b)

The aim of this study was to clarify the impact of infiltration pattern on prognosis in patients with gastric carcinoma invading subserosa.Clinicopathologic findings in patients with ssgamma pattern (n = 144) were compared with those in patients with ssalpha/ssbeta cancers (n = 222). Prognostic factors of pT2b patients were analyzed by univariate and multivariate analysis.Compared with the ssalpha/beta group, ssgamma gastric cancer exhibited more frequent undifferentiated histology, disseminated lymph node metastasis and perineural invasion. Frequency of postoperative peritoneal recurrence was significantly higher in ssgamma gastric cancer (P < 0.05). The 5-year survival rate for patients with ssgamma gastric cancer was significantly lower compared with ssalpha/beta group (63.2% vs. 74.8%, respectively; P < 0.05). Lymph node metastasis, vein invasion and infiltrative pattern (ssgamma) were significant independent prognostic factors affecting survival in pT2b patients.In patients with gastric cancer invading the subserosa, infiltrative type growth pattern is closely related to carcinomatosis and poorer prognosis.