Clinicopathological characteristics and survival outcomes of younger patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND: Survival outcomes of gastric cancer in younger patients have been reported in several studies with controversial results. This systematic review and meta-analysis investigated the clinicopathological characteristics, postoperative complications, and survival outcomes between younger and older patients. METHODS: We systematically reviewed clinical researches from PubMed, The Cochrane Library, Embase, and Web of science published up to December 2019. The effect size for the included studies was estimated with the odds ratio (OR). Heterogeneity was investigated using the χ(2) test and I(2) test, while sensitivity analyses were performed to identify the source of substantial heterogeneity. RESULTS: A total of 25 clinical studies involving 81,188 gastric cancer patients were included in this meta-analysis, of which one was a prospective study. Younger patients were more likely to be females, pTNM stage IV and peritoneal metastasis. The incidence of postoperative complications, lymph node metastasis, as well as hepatic metastasis of younger patients was significantly lower than that of the older. There was no statistical difference in overall survival (OS) between the younger and older patients with gastric cancer. After stratification for patients with gastrectomy, however, younger patients were associated with a better 5-year OS relative to older patients. CONCLUSIONS: In conclusion, younger patients with gastric cancer were more often diagnosed as poorly differentiation and later pTNM tumor stage. However, younger cancer patients following gastrectomy had a better OS rate than patients in older group. Future large-scale analyses are expected to confirm our findings.