Analysis of prognostic factors and outcomes of gastric cancer in younger patients:A case control study using propensity score methods

AIM:To understand the clinicopathological and prognostic features of gastric cancer in younger and older patients.METHODS:Between January 2002 and December2008,1667 patients underwent curative gastric surgery.For comparative purposes,the patients were divided into two groups:younger patients who were less than 40 years old(112 patients),and older patients who were 40 years old and older(1555 patients).In both groups,propensity scoring methods were used to select patients with similar disease statuses.A total of224 matched cases,with 112 patients in each group,were included in the final analysis.RESULTS:Compared to the older group,the younger group with gastric cancer had a significantly higher percentage of females(P=0.007),poorly differentiated or signet ring cell carcinoma(P<0.001),advanced T stage gastric cancer(P=0.045),and advanced tumornode-metastasis stage cancer(P=0.036).The older group with gastric cancer had more comorbidities(P<0.001).With the exception of the number of lymph node dissection(P<0.001)and retrieved lymph node(P=0.010),there were no statistically significant differences between the postoperative outcomes of the two groups.During the follow-up period,there were19 recurrences in the younger group and 11 recurrences in the older group.The overall five-year survival rates in the younger and older groups were 84.3%and89.6%,respectively(P=0.172).There were no significant differences(P=0.238)in the overall survival of patients with advanced T stage gastric cancer in the two groups,with five-year survival rates of 70.8%in the younger group and 79.5%in the older group.With regard to the age-adjusted survival rate,there was significant difference between the two groups(P=0.225).CONCLUSION:In spite of aggressive cancer patterns in the younger group with gastric cancer,the younger group did not have a worse prognosis than the older group in our study.