Birth Control May Increase the Risk of Breast Cancer
Oral contraceptives increase the risk of breast cancer by an average of 44 percent in pre-menopausal women who took – or were taking – oral contraceptives (OCs) prior to their first pregnancy (as compared to women who had not used OCs), according to a comprehensive analysis of international studies conducted between 1980-2002, linking breast cancer and contraceptives. ["Oral Contraceptive Use as a Risk Factor for Pre-menopausal Breast Cancer: A Meta-analysis", published in the journal of the Mayo Clinic, October 2006]
Of the 23 studies examined, 21 showed an increased risk of breast cancer with OC use prior to a first pregnancy in pre-menopausal women.
The study seems to reinforce the 2005 classification of oral contraception as a Type 1 carcinogen (cancer-causing agent) to humans by the International Agency for Cancer Research.