Signet ring cell mixed histology may show more aggressive behavior than other histologies in early gastric cancer

Abstract

OBJECTIVES: Signet ring cell carcinoma (SRC) of the stomach has been known to have different microscopic and biologic characteristics compared to non-SRC. Thus, a pathologic report has documented partly SRC component with other main histologies in gastric cancer. However, the clinical significance of SRC mixture has not been reported. The aim was to investigate clinicopathologic features of mixed-SRC histology in early gastric cancer (EGC).METHODS: Between 1999 and 2005, 2208 patients were diagnosed with EGC and underwent surgery at Severance and Gangnam Severance Hospital. Among them, 156 patients were diagnosed with adenocarcinoma with partly SRC (mixed-SRC group), 1,512 with only adenocarcinoma (adenocarcinoma group), and 540 with SRC (SRC group). Clinicopathologic characteristics among the mixed-SRC, adenocarcinoma, and SRC groups were analyzed.RESULTS: The SRC group was more significantly associated with younger age, female, mid-body location, mucosa-confined, depressed type, lower lymph node metastasis (LNM), lower lymphovascular invasion, and a better survival rate than the adenocarcinoma group. The mixed-SRC group was more significantly associated with younger age, female, upper-body location, and depressed type than the adenocarcinoma group, similar to the SRC group. However, the mixed-SRC group showed more submucosal invasion, larger size, and higher LNM than SRC and adenocarcinoma groups. Also, a mixed-SRC component was one of the independent risk factors of LNM.CONCLUSIONS: The mixed-SRC group displayed different clinicopathologic characteristics from other groups. Mixed-SRC histology in EGC showed more aggressive biologic characteristics than SRC and adenocarcinoma. Thus, clinical considerations of mixed-SRC histology may be helpful to decide on a specific cancer treatment.