Prognosis of signet ring cell (SRC) gastric carcinoma (GC) compared with other histological subtypes.

357 Background: Signet ring cell (SRC) gastric cancer (GC) has its unique clinicopathological features with poor tissue differentiation, high invasiveness, diffuse growth pattern and poor prognosis. Survival rates and clinicopathological characteristics of patients with SRC GC regardless of the stage of the disease has not been well studied. Methods: The retrospective analysis was undertaken of 993 patients with diagnosed gastric cancer. These patients received surgical resection in period from January 2013 to December 2018 in N.N. Blokhin National Medical Research Center of Oncology. We compared clinical and pathological features as well as prognostic factors between these groups. Results: For early SRC carcinoma, the median survival rates weren’t reached; 3- and 5-year survival rates were 100% and 89.0 %; for non-SRC carcinoma 91.4 and 85.3 % (HR=0.73; 95 % CI 0.22–2.42, р = 0.6) respectively. For locally advanced/metastatic SRC carcinoma, the median survival rates, 3- and 5-year survival rates were 38 months, 53.0 and 38.4 %; for non-SRC carcinoma 51.1 months, 59.2 and 48.0 % (HR=1.2; 95 % CI 0.91–1.54, р = 0.2). At univariate analysis SRC morphology was found as independent risk factor for overall survival (HR=1.19; CI 95% 0.94 – 1.50; p<0.0001). Multivariate analysis did not reveal SRC morphology to be significant and independent risk factor for overall survival (HR=1.00; CI 95% 0.72 – 1.38; p=0.98). Conclusions: Overall survival rates in patients with early (mucosal and submucosal tumor regardless of lymph nodes status) SRC gastric cancer did not show any significant differences in comparison with other histological types of GC. Thus, the prognosis of early SRC GC is equivalent or better than that of other histological subtypes of GC. Overall survival rates of locally advanced/metastatic SRC gastric cancer are worse than non-SRC cancer, but the differences are not statistically significant.