impact of familial clustering on the risk of development of gastric cancer:a meta-analysis

background: it is presumed that gastric cancer has several etiologies. first-degree relatives of patients with gastric cancer are suggested to be at higher risk compared to others. this is the first study aimed at estimating this risk, using meta-analysis of case-control studies. materials and methods: all records prior to february 2008 in pubmed and embase were searched for case-control studies comparing the frequency of positive family history of gastric cancer in patients with the cancer vs those without gastric cancer. meta-analysis of pooled odd ratio (random model) was performed by software review managerâ®, ver 4.2. results: fourteen studies out of 113 potential abstracts were included. these included 8,506 patients in gastric cancer group and 53,782 in the control group. 23.5% of the patients and 11.5% of the controls had at least one relative with gastric cancer (p‹0.00001). relative risk for development of gastric cancer in those with a positive family history to controls was 2.86 (95% ci: 2.21-3.70). there was a significant large heterogeneity in the findings of the studies. the heterogeneity was only low in studies with high quality scores. subgroup analyses of studies in asian populations, studies with higher quality scores, those with study question as the primary objective and those considering only first-degree relatives were not significantly different from those studies in populations. conclusion: patients with a first- or second-degree relative with gastric cancer are almost 3 times more likely to develop gastric cancer compared to other people. screening guidelines should be developed to early diagnosis and management of gastric cancer in this population. govaresh/ vol. 12, no. 4, winter 2008; 235-238