Résumé :
|
[BDSP. Notice produite par INIST FMAR0xLt. Diffusion soumise à autorisation]. Results from studies of western populations investigating lactation and breast cancer risk have been inconsistent. To examine this issue, the authors conducted a hospital-based case-control study in Shandong Province, China, in 1997-1999. A total of 404 cases and an equal number of controls were included. Detailed information regarding lactation, menstruation, and reproduction was collected through in-person interview. The authors found a significant inverse association between duration of lactation and breast cancer risk. For women who breastfed for more than 24 months per child, the odds ratio was 0.46 (95% confidence interval (Cl) : 0.27,0.78) when compared with those who breastfed for 1-6 months per child. A significantly reduced risk of breast cancer was also found for those whose lifetime duration of lactation totaled 73-108 months (odds ratio=0.47,95% Cl : 0.23,0.95) and for those who breastfed for >=109 months (odds ratio=0.24,95% Cl : 0.11,0.53). The test for trend was statistically significant for both mean duration of lactation per child (p=0.02) and lifetime duration of lactation (p=0.00). Further stratification by menopausal status resulted in the same conclusion. These data suggest that prolonged lactation reduces breast cancer risk.
|