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

BACKGROUND: Signet ring cell carcinoma (SRC) of the stomach is known to have different microscopic and biologic characteristics compared to non-SRC. The pathologic report has documented partly SRC component with main histologies. However, the clinical significance of SRC mixture has not been reported. Aim was to investigate clinicopathologic features of mixed-SRC histology in early gastric cancer (EGC). METHODS: Two thousand two hundred eight patients were diagnosed with EGC and underwent surgery. The patients were divided into three groups such as adenocarcinoma with partly SRC (mixed-SRC group), only adenocarcinoma (adenocarcinoma group), and SRC (SRC group). Clinicopathologic characteristics were compared. RESULTS: The SRC group was more associated with younger age, female, mid-body, mucosa-confined, depressed type, lower lymph node metastasis (LNM), lower lymphovascular invasion, and better survival rate than adenocarcinoma group. The mixed-SRC group was more associated with younger age, female, upper-body, and depressed type than adenocarcinoma group, similar to SRC group. However, the mixed-SRC group showed more submucosal invasion, larger size, and higher LNM than other groups. The mixed-SRC component was one of the independent risk factors of LNM. CONCLUSIONS: Mixed-SRC histology in EGC showed more aggressive behavior than other histologies. Clinical considerations of mixed-SRC histology may be helpful to decide on a specific cancer treatment.