The Gastric Cancer-Specific Survival In Adenocarcinoma With Different Histological Subtypes

Background/purpose: Asa special subtype of adenocarcinoma,gastric signet ring cell carcinoma(GSRC)has been considered a histological type with poor survival and should be treated differently.However,with the profoundlystudyon gastric cancer,more and more scholars have put forward different views.The main purpose of this study is to compare the survival outcomes between patients with GSRC and patients with gastric non-signet ring cell adenocarcinoma(NGSRC)and constructed a nomogram to predict gastric adenocarcinoma-specific survival(GCSS),so that the medical profession can have an objective,comprehensive and accurate prediction in the prognosis of patients with gastric adenocarcinoma(GA).Methods:we downloaded SEER database,extracted clinical information of 40882 patients with GA from the database using Stat software provided by its official website,and finally determined 10031 patients according to the inclusion and exclusion criteria.According to different pathological types,the patients were divided into two groups: GSRC group and NGSRC group.The patients in GSRC group and NGSRC group were matched by using the method of propensity score matching(PSM)with SPSS software,so that the clinical characteristics of the two groups were basically similar.Finally,2152 pairs(4304 cases)of patients were screened,and they were used as the training cohort to establish the prediction model in the later stage.Kaplan Meier curve was used to evaluate the effect of histological types on GCSS.The independent risk factors of GA were obtained by univariate and multivariate analysis.4304 patients were used as the training cohort to construct the prediction model nomogram,and the other 5727 patients were used as the validation cohort to test the accuracy of nomogram.C-index was used to evaluate the prognosis model,ROC curve and calibration chart were used to evaluate the sensitivity and specificity of nomogram.Results: we found that the GCSS of GSRC and NGSRC were the same(1-year survival rate: 74.5% vs 74%,P = 0.649,3-year survival rate: 51.9% vs 51.7%,P =0.850,5-year survival rate: 46.1% vs 46.7%,P = 0.822).In different TNM stages,the GCSS were the same: stage I patients(GSRC as reference,HR = 0.996,95%confidence interval(CI)0.790-1.256,X2 = 0.001,P = 0.975),stage II patients(GSRC as reference,HR = 0.998,95% CI 0.848-1.176,X2 < 0.001,P = 0.985),stage III patients(GSRC as reference,HR = 1.013,95% CI 0.904-1.134,X2 =0.051,P = 0.822)and IV patients(GSRC as reference,HR = 0.839,95% CI 0.682 –1.034,X2 = 2.892,P = 0.089).The nomogram showed that histological type was a relatively weak predictor of survival.The C-index value and the AUC of the nomogram for predicting survival were 0.720 and 0.804,respectively,similar to that in the validation cohort.Conclusions: Patients with GSRC had a similar prognosis to those with NGSRC.The proposed nomogram allowed a relatively accurate survival prediction for operable GA patients after gastrectomy.