BACKGROUND: In East Asia, the tumor infiltrative pattern (INF) has been routinely evaluated by hematoxylin and eosin-stained sections as a pathologic characteristic of surgically resected specimens. METHODS: The infiltrative pattern of gastric cancer (GC) has been histopathologically classified as INFa (expansive growth), INFb (intermediate type) and INFc (infiltrative growth) according to the Japanese Classification of Gastric Carcinoma. The prognostic value and characteristics of the disease recurrence pattern for each INF type were assessed in 785 patients with various stages of GC and also in 243 patients with stages 2 and 3 GC. RESULTS: Comparison of the overall survival experienced by patients independently of stage showed that INF was significantly associated with prognosis. Specifically, peritoneal metastasis was present in 91 % of stage 4 patients in the INFc group, whereas hepatic metastasis was present in 39 % of stage 4 patients in the INFa and INFb group. After curative gastrectomy of patients with stages 2 or 3 GC, INF was not significantly associated with survival. The prevalence of peritoneal recurrence was significantly higher in the INFc group than in the INFa and INFb group, whereas the prevalence of hepatic recurrence was significantly higher in the INFa and INFb group than in the INFc group. Multivariate analysis identified INFc as an independent risk factor for peritoneal recurrence after curative gastrectomy. The association of the INF type with the incidence of peritoneal recurrence was observed with all disease stages regardless whether the patient was given adjuvant chemotherapy or not. CONCLUSIONS: Evaluation of the INF type shows promise for its role as a predictor of postoperative recurrence sites in patients with GC.
BACKGROUND: In East Asia, the tumor infiltrative pattern (INF) has been routinely evaluated by hematoxylin and eosin-stained sections as a pathologic characteristic of surgically resected specimens. METHODS: The infiltrative pattern of gastric cancer (GC) has been histopathologically classified as INFa (expansive growth), INFb (intermediate type) and INFc (infiltrative growth) according to the Japanese Classification of Gastric Carcinoma. The prognostic value and characteristics of the disease recurrence pattern for each INF type were assessed in 785 patients with various stages of GC and also in 243 patients with stages 2 and 3 GC. RESULTS: Comparison of the overall survival experienced by patients independently of stage showed that INF was significantly associated with prognosis. Specifically, peritoneal metastasis was present in 91 % of stage 4 patients in the INFc group, whereas hepatic metastasis was present in 39 % of stage 4 patients in the INFa and INFb group. After curative gastrectomy of patients with stages 2 or 3 GC, INF was not significantly associated with survival. The prevalence of peritoneal recurrence was significantly higher in the INFc group than in the INFa and INFb group, whereas the prevalence of hepatic recurrence was significantly higher in the INFa and INFb group than in the INFc group. Multivariate analysis identified INFc as an independent risk factor for peritoneal recurrence after curative gastrectomy. The association of the INF type with the incidence of peritoneal recurrence was observed with all disease stages regardless whether the patient was given adjuvant chemotherapy or not. CONCLUSIONS: Evaluation of the INF type shows promise for its role as a predictor of postoperative recurrence sites in patients with GC.