Does family history of cancer modify the effects of lifestyle risk factors on esophageal cancer? A population-based case-control study in China.

A population-based case-control study on esophageal cancer has been conducted since 2003 in Jiangsu Province, China. The aim of this analysis is to provide further evidence on the relationship between family history of cancer in first-degree relatives (FH-FDRs) and the risk of esophageal cancer, and to explore the joint effects for FH-FDR with major lifestyle risk factors. A total of 1,520 cases and 3,879 controls were recruited. Unconditional logistic regression was applied for evaluating independent association as well as potential interactions between FH-FDR and lifestyle risk factors on the risk of esophageal cancer. Population attributable fraction (PAF) was calculated to quantify the proportion of cases attributable to risk factors. Results showed that with a FH-FDR of any malignant tumor or esophageal cancer, there is a 1.64- and 2.22-fold risk of esophageal cancer, respectively. Association was increased when there was more than one affected FDR (OR = 3.14) and younger age at diagnosis of relatives. Exposure of both FH-FDR and lifestyle risk factors strongly associated with esophageal cancer. Significant superadditivity interaction was found for FH-FDR with fast eating speed and diets low in fruits and vegetables. The estimation of PAF indicated that the majority of cases were attributed to lifestyle risk factors. In conclusion, it was found that FH-FDR significantly increases the risk of esophageal cancer and could modify the effect of certain lifestyle risk factors. If comprehensive lifestyle interventions are carried out within high-risk populations, there is a high probability of curbing occurrences of esophageal cancer.