Aims and background: The aim of the present study was to examine if certain aspects of a woman's experience of abortion might be associated with the risk of breast cancer.
Methods and study design: The case-control study was conducted in Kragujevac (Serbia) during the period 2004-2005. The case group (191 women) consisted of patients with newly diagnosed first primary breast cancer, which was histologically confirmed. The control group (191 women), individually matched by age (± 2 years), hospital admittance and place of residence (rural/urban) to the respective cases, was selected from female patients admitted for other diseases. The analysis was restricted to parous women (168 cases and 171 controls).
Results: Breast cancer risk was reduced among women who had a history of any abortion (adjusted OR, 0.46; 95% CI, 0.24-0.88). The protective effect was found for both induced abortion (adjusted OR, 0.47; 95% CI, 0.25-0.90) and spontaneous abortion (adjusted OR, 0.31; 95% CI, 0.10-0.98). It seems that these associations did not depend on the number of abortions, age at first abortion, or gestational age at first aborted pregnancy.
Conclusions: Our study suggests that even short pregnancies ending in abortion add to the protection against breast cancer.