An article in the most recent issue of the medical journal Cancer Research details yet another study demonstrating a link between breast cancer in young women and the use of oral contraceptives.
The authors point out that their study is unique because it relies on electronic pharmacy records, instead of just self-reporting, to accurately verify contraceptive use. In addition, they look at the various formulations of hormonal contraceptives to elucidate variances in risk dependent upon which contraceptive is used.
They looked at the contraceptive use of 1,100 women between the ages of 20 and 49 who had been diagnosed with breast cancer and compared them to a control group of nearly 22,000 women.
What they found was that there was an overall 50% increase in the risk of breast cancer in women who had used any oral contraceptive in the last year. This risk was independent of family history. They also identified specific risks associated with the different contraceptive formulations, noting that the larger the estrogen component of the contraceptive, the greater the increased risk.
Moderate strength estrogen contraceptives increased the risk of breast cancer by 1.6 fold. High dose estrogen contraceptives increased the risk of breast cancer by 2.7 fold.
The use of the popular triphasic oral contraceptives that are supposed to more closely mimic the body’s natural hormonal variations actually more than tripled the breast cancer risk. The progestin component of oral contraceptives also contributed to the breast cancer risk with the increased risk varying from 1.5 fold to 3 fold, depending on which progestin is used.
Breast Cancer Screening
Breast cancer in women between the ages of 20 and 49 is very different than breast cancer in post-menopausal women. Younger women usually have a more aggressive form of breast cancer that is less responsive to therapy. Therefore, anything that increases the risk of breast cancer in younger women will increase the number of women who die from breast cancer. Urging young women to avoid hormonal contraceptives seems to be a reasonable step to fight this disease.
Therefore, it is surprising to hear the lead investigator of this study downplaying the significance of their findings. Dr. Elisabeth Beaber of the Fred Hutchinson Cancer Research Center in Seattle, Washington states:
As she clearly pointed out in her article, this is not the only study that has found a relationship between oral contraceptive use and breast cancer. Her study collected the data on contraceptive use more accurately than previous studies and still found the risk of breast cancer significantly increased in oral contraceptive users.
What benefits could possibly outweigh this risk? Decreased acne? Less menstrual cramping? Lighter periods?
Some will be quick to point out the possibility of decreased risk for ovarian cancer as a compensatory benefit of oral contraceptive use. The lifetime risk of being diagnosed with breast cancer is 1 in 10. The lifetime risk of being diagnosed with ovarian cancer is about 1 in 72. Therefore, to suggest that the decreased risk of ovarian cancer with oral contraceptives balances the increased risk of breast cancer is like saying you will double or triple your risk of being involved in an automobile crash in order to decrease your risk of being involved in a train accident. It just doesn’t make sense.