Reproductive factors and oesophageal cancer in Chinese women: a case-control study

BACKGROUND Previous studies showed that sex hormone might play a role in the development of oesophageal cancer in Western countries. However, evidence from Chinese populations is still lacking. METHODS We performed a hospital-based case-control study in Guangzhou, China. From June 2006 to May 2009, face-to-face interviews were conducted on 73 cases and 157 controls. Cases were Chinese females with newly diagnosed primary oesophageal cancer. Controls were hospitalized individuals without cancer and frequency matched by age groups. The interviews included questions about childbearing and menarche history, together with potential confounders. Unconditional logistic regression was used to estimate the risk of factors. RESULTS Women who had given birth before were not at increased risk compared to childless women (adjusted OR = 1.17, 95% CI: 0.48 ~ 2.85). The risk of oesophageal cancer increased with age at first birth: the adjusted OR for women first giving birth at age 25 or later was 2.02 (95% CI: 1.01 ~ 4.04) compared with those reporting their first birth before age 22. History of spontaneous abortion was not significantly associated with increased risk (adjusted OR = 1.37, 95% CI: 0.49 ~ 3.83). No significant association was observed between menstrual variables (age at menarche, age at menopause, and years of menstruation) and risk of oesophageal cancer. CONCLUSIONS Giving birth at later age may increase the risk of oesophageal cancer in women. Further studies in Chinese populations with larger sample sizes are still needed.