Clinical Features And Prognosis Analysis Of Patients With Gastric Cancer As A First Multi-Primary Cancer

Objective:The clinical characteristics of patients with gastric cancer as first multi-primary cancer(GCFMPC)were reviewed and analyzed by univariate and multivariate regression to better understand the prognosis of patients with GCFMPC and provide a basis for the diagnosis,treatment and follow-up management of such patients.Methods:Based on SEER database(National Cancer Database of the United States),this study selected the clinical data of GCFMPC patients from December 2009 to December 2019.Frequency(n),percentage(%)and chi-square test were used to describe the distribution of patients with GCFMPC on different clinical characteristics;Logistic regression model was used to analyze the risk factors that might affect the prognosis,and Cox risk regression model was used to analyze the multiple factors;Kaplan-Meier method was used to draw survival curve with R-studio 4.2.2 software;Log-rank was used to compare the effect of different risk factors stratification on prognosis and the difference in survival of patients with GCFMPC at different time intervals.P<0.05 was considered statistically significant.Results:In 930 patients with GCFMPC,the number of patients with different clinical characteristics is distributed as follows:Gender: male accounted for 62.6%,female 37.4%;Age:<60 years old accounted for 24.1%,60-80 years old accounted for 64.5%,>80 years old accounted for 11.4%;Histological grading: high differentiation accounted for18.2%,medium differentiation accounted for 31.1%,low differentiation accounted for 48.1%,and undifferentiated accounted for 2.6%;T stage: Tis accounting for 1.7%,T1 accounting for 35.6%,T2 accounting for 17.8%,T3 accounting for 30.1%,T4 accounting for 14.7%;N stage: N0 accounts for63.3%,N1 accounts for 22.6%,N2 accounts for 8.3%,and N3 accounts for5.8%;M stage: M0 accounting for 89.5%,M1 accounting for 10.5%;TNM stage: stage 0 accounts for 1.7%,stage Ⅰ accounts for 38.9%,stage Ⅱ accounts for 25.9%,stage Ⅲ accounts for 22.9%,and stage Ⅳ accounts for10.6%;Whether to operate or not: 78.8% of patients were operated and21.2% were not operated;Radiotherapy or not: radiotherapy accounted for32% and no radiotherapy accounted for 68%;Chemotherapy or not:chemotherapy accounted for 52.2% and no chemotherapy accounted for47.8%;The interval between the onset of multiple primary carcinoma(MPC):simultaneous MPC accounted for 30.6%,and isochronous MPC accounted for 69.4%.Among them,the distribution of age,M stage,TNM stage,and whether or not to operate were statistically significant in the distribution of simultaneous MPC and heterochronism MPC(P<0.05).The digestive system is the best site of the second primary cancer,and gastric cancer is still the most common,with 144 cases,accounting for 19.5%(P<0.05).In univariate analysis,age,histological grade,T stage,N stage,M stage,TNM stage,operation,radiotherapy,chemotherapy and the interval between onset of MPC had statistical significance on the survival and prognosis of patients with GCFMPC(P<0.05).In multivariate analysis,age,histological grade,operation,chemotherapy and the interval between onset of MPC had statistically significant effects on the survival and prognosis of patients with GCFMPC(P<0.05).In this study,the overall survival time of patients with GCFMPC was 0-119 months,the median survival time was 29 months,and the 1,3 and 5 year survival rates were 70.1%,46.6% and 39.0% respectively.The overall survival time of patients with concurrent GCFMPC was 0-119 months,and the overall survival rates of 1,3 and 5 years were 73.1%,46.1%and 35.6% respectively.The overall survival time of patients with metachronous GCFMPC was 0-110 months,and the overall survival rates of1,3 and 5 years were 69.0%,47.3% and 42.9% respectively.Conclusions:1.Among the patients with GCFMPC,male,60-80 years old,with low and moderate differentiation,T1,T3,N0,M0,Ⅰ,Ⅱ,Ⅲ,surgery and no radiotherapy account for a high proportion,and the patients are mainly metachronous GCFMPC.2.Digestive system is the most common site of the second primary cancer in patients with GCFMPC,among which gastric cancer is still the most common.3.Age,histological grade,T stage,N stage,M stage,TNM stage,surgery,radiotherapy,chemotherapy and the interval between MPC attacks are risk factors that affect the prognosis of GCFMPC patients.Age,histological grade,N stage,operation,chemotherapy and the interval between MPC attacks are independent risk factors affecting the prognosis of patients with GCFMPC.4.The 5-year survival rate of metachronous GCFMPC patients is higher than that of synchronous GCFMPC patients.