Association of stomach cancer risk in individuals with family history of cancer

Though increased risk of gastric cancer in individuals with family history of the disease has been observed consistently in previous studies, data on the association between gastric cancer and family history of cancer from Iran is scanty. The purpose of this study is to evaluation of gastric cancer risk associated with family history cancer. The present study was designed as unmatched case-control study. Cases were 746 histopathologically confirmed gastric cancer and 746 controls were randomly selected among the healthy participants in a health survey. The family history of cancer was extracted from a standard history form completed by the patients or health care providers. Mantel-Heanszel Odds Ratio was computed for removing the confounding effect of age and sex. A positive family history of cancer was reported by 9.7% and 5.6% of cases and controls, respectively. Gastric cancer risk increased two-fold for subjects reporting any first degree relative with gastric cancer. There is no statistical association among family history of other cancers and gastric cancer (P>0.05). In conclusion, this study showed that family history of gastric cancer, especially in first-degree relatives, increases the risk of gastric cancer. Further studies are needed to better understand the role of genetic factors and environmental factors and their interaction in gastric cancer development in Iranian community.