Eur J Cancer, 2010
Deirdre P. Cronin-Fenton1*, Chris Cardwell2, Liam J. Murray2, David C. Whiteman3, Penelope M. Webb3, Susan J. Jordan3,4, Douglas A. Corley5, Linda Sharp6, Jesper Lagergren7, on behalf of the BEACON investigators.
Background: The rapidly rising incidence and the striking male predominance are as yet unexplained features of esophageal adenocarcinoma (EAC). Few and underpowered studies have examined the impact of female reproductive factors on EAC risk in women. We therefore pooled data on women from four population-based case-control studies to examine the association of female reproductive and sex hormonal factors with EAC.
Methods: Data on women from case-control studies conducted in Ireland, the UK, Australia and USA were pooled. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for a range of reproductive factors, adjusted for age, study, and major risk factors for EAC.
Results: We included 218 cases and 862 controls. Among parous women, a reduced risk of EAC was found after breastfeeding (OR=0.58, 95%CI=0.37-0.92) and the risk decreased with increased duration of breastfeeding (>12 months OR=0.42, 95%CI=0.23-0.77). The endogenous reproductive factors parity, menstruation, history of pregnancy, and the exogenous factors use of oral contraceptives and of hormone replacement therapy were not statistically significantly associated with EAC.
Conclusions: Our findings suggest that breastfeeding is associated with a decreased risk of EAC. The potential mechanism of this association warrants further investigation.