To the Editor: In the article, “ Menstrual manipulation: Options for suppressing the cycle ,”1 the authors described advantages and disadvantages of various hormone-based methods of menstrual manipulation, including prolonged use of oral contraceptives. We believe the authors underemphasized the risks associated with oral contraceptives. Blood clots, stroke, and death are often included in print and television ads by law firms recruiting patients harmed by these drugs. In addition, the authors failed to mention the risk of premenopausal breast cancer due to oral contraceptives, which are now classified as group 1 carcinogens by the World Health Organization. 2
In October 2006, we published the most current meta-analysis to date regarding oral contraceptive use and the risk of premenopausal breast cancer. 3 We found that 21 out of 23 studies showed a positive trend or positive risk for premenopausal breast cancer with oral contraceptive use prior to first-term pregnancy. This resulted in a highly statistically significant cumulative risk of 44% (ie, odds ratio 1.44, 95% confidence interval 1.24–1.68). Our meta-analysis remains the most recent study in this area and updates the Oxford pooled analysis, 4 which relied on older studies with older women (two-thirds of whom were over age 45).
A more recent collaborative study coauthored by investigators from the National Cancer Institute, the Hutchinson Cancer Research Center, and the University of Washington includes oral contraceptives in the list of risk factors for breast cancer in younger women. 5 We ask your readers to consider that patients are entitled to know about this important risk factor before making a decision regarding hormonal menstrual manipulation.