The Link Between Infertility Treatment and Breast Cancer

According to, fertility treatments seem to affect breast cancer risk in younger women who succeed in conceiving. These findings are from a July 12, 2012, study by the Journal of the National Cancer Institute. Women whose fertility treatments resulted in conception were found more likely to develop breast cancer than those who did not conceive.

To be clear, those who were more likely to develop breast cancer had about the same risk as the average woman; still, their risk was found to be higher than that of women who had fertility treatments but did not conceive.

Fertility Drugs and the Ovaries

When a woman takes fertility drugs, the ovaries are stimulated to create more mature eggs than they would normally. As many as eight to ten mature eggs are released as a result. This is opposed to two to three (at most) during normal menstruation.

The Connection to Breast Cancer

Using fertility drugs also causes estrogen to increase. This extra estrogen is the true culprit when it comes to breast cancer. “The extra estrogen may stimulate the growth of hormone-receptor-positive breast cancer cells.”

It is important to keep in mind that previous studies on this subject have had mixed results. Therefore, although the 2012 findings illuminate the issue, the link between the two is not considered conclusive or definite.

The Two-Sister Study

The 2012 study, called The Two-Sister Study, involved “1,422 women who had been diagnosed with breast cancer when they were younger than 50 and their 1,669 sisters who hadn’t been diagnosed. The women self-reported whether they had ever taken fertility drugs.”

Interestingly, women who took fertility drugs but did not conceive had a lower instance of breast cancer than women who didn’t use any fertility drugs. But the researchers did not conclude it was the fertility drugs themselves which protected against breast cancer. Instead, it was hypothesized women who don’t conceive even after fertility treatments have lower estrogen levels overall. The lack of excess estrogen was assumed to be the determining factor.

The women who took fertility drugs and did conceive had a higher instance of breast cancer than the first group. Yet even among this group, the rate of breast cancer was about the same as in the general population. To be clear, the women who conceived were more likely to develop breast cancer than those who did not conceive, but they were still about as likely as the average woman to develop the disease.

Lessons About Fertility Drugs and Breast Cancer

If you are having trouble conceiving and are considering fertility drugs, you can rest assured that taking the drugs will not raise your risk for breast cancer above the average.

It is also important to know that women who conceive a child without any fertility drugs are not more likely to develop breast cancer.

Breast Health in Houston

Dr. Darlene Miltenberg at Breast Health Institute Houston is a highly sought after surgeon who specializes in treating breast cancer and diseases of the breast. BHIH uses state of the art genetic testing, imaging, and pathology to detect breast cancer as early as possible.

We use evidence-based treatments and strive to leave our patients looking even better than they did before. If you want a second opinion, need a mammogram, breast biopsy in Houston, or other breast-related treatment, contact Dr. Darlene Miltenberg at Breast Health Institute Houston today.

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