Evaluating whether there is an association between fertility treatments and the risk of breast cancer in women with a family history of breast cancer or with BRCA mutations.

This study evaluated whether fertility treatments increase the risk of breast cancer (BC) in women with a family history of BC or with BRCA mutations. The data showed that fertility treatments did not significantly increase the risk of BC in these women.

Treatment for infertility has become common, as people delay having children and as the condition is more commonly treated. Ovarian stimulation (OS) is an important aspect of treatment for infertility. OS uses hormonal medications to cause multiple oocytes (eggs) to mature in a single menstrual cycle. Letrozole (Femara) and clomiphene citrate (CC; Clomid) are drugs commonly used for ovarian stimulation in women with infertility. OS increases the levels of estrogen (female reproductive hormone) to much higher levels than is found in a natural menstrual cycle.

Estrogen affects organs throughout the body, including the uterus, brain, and bones. In particular, estrogen affects the breast tissue. Each month, breast tissue grows and matures in response to the hormones- estrogen, and progesterone. Over time, this normal tissue growth due to estrogen can contribute to breast cancer risk. While not all BCs are the same, many of them grow in response to these hormones. Women who have longer periods of time with high estrogen due to irregular cycles also may have a higher risk of BC. BRCA1 and BRCA2 gene mutations (abnormalities) can be found in many patients with BC. BRCA1/BRCA2 genes block the rapid and uncontrolled growth of cells, therefore the formation of tumors. Harmful variations of these genes are often found in young patients and can be very resistant to current treatment options.

There is a need to evaluate whether fertility treatments increase the risk of BC in women with a family history of BC or with BRCA mutations.

This study analyzed 8 studies and involved a total of 4352 patients with BC. 350 of these women were treated with fertility treatments.

There was no significant increase in the risk of BC by fertility treatments in general genetically susceptible women, women with a family history of BC, or women with BRCA mutations.

There was no significant increase in the risk of BC by fertility treatments in women with carriers of BRCA1 or BRCA2 mutations.

There was no significant increase in the risk of BC by fertility treatments in women treated with IVF, clomiphene citrate, or gonadotropins (Gonal-F).

This study concluded that fertility treatments did not significantly increase the risk of BC in women with a family history of BC or with BRCA mutations.

The number of studies analyzed was very small and had short follow-up periods. Data on overall survival was missing. Large, prospective studies are needed to confirm these findings.