Breast Cancer Health Center

How Breast Cancer Affects Fertility

Breast cancer can be scary enough without wondering if it will also prevent you from having children. More and more American women are diagnosed with breast cancer in their childbearing years, and many want to know how the disease will affect their fertility.

While there's no one-size-fits-all answer to this complex question, WebMD asked the experts for answers to some tough questions including: What are risks posed by cancer treatment, methods of preserving fertility, and ways cancer might affect future offspring.

More than 11,000 women under 40 are diagnosed with breast cancer in the U.S. each year. How breast cancer treatment affects fertility depends largely on three factors: the type of treatment used, type and stage of the cancer at diagnosis, and the age of the patient.

Type of treatment

Not all breast cancer treatments affect fertility.

"If a patient needs only surgery and radiation and no chemotherapy, the treatment will have no impact on future fertility," Robert Barbierri, MD, chief of obstetrics and gynecology at Brigham and Women's Hospital in Boston, tells WebMD. The same, however, cannot be said for chemotherapy.

Breast cancer patients treated with chemotherapy run the risk of developing premature ovarian failure or very early menopause. Almost four out of five women treated with cyclophosphamide -- an often-prescribed chemotherapy drug for treating breast cancer -- develop ovarian failure, according to Kutluk Oktay, MD, assistant professor of reproductive medicine and obstetrics and gynecology at Cornell's Center for Reproductive Medicine and Infertility. FertileHope, a nonprofit organization dedicated to disseminating education on infertility associated with breast cancer treatment, places the risk at 40% to 80%.

Type and Stage of Cancer

How advanced a cancer is upon detection, as well as what type it is, dictate whether chemotherapy will be required, thereby affecting the risk of side effects to the ovaries.

The more advanced the cancer upon detection, the greater likelihood that chemotherapy, which affects the whole body, will be used to treat it. For instance, invasive breast cancer typically requires systemic chemotherapy, whereas a small tumor with small nodes that is localized and contains a minimal threat of spreading may not.

The type of tumor also impacts a patient's treatment options. Some breast cancers can be treated with the use of hormone-containing drugs. But a small percentage of breast cancer tumors are "hormonally insensitive," explains Susan Domcheck, MD, assistant professor of medicine at the University of Pennsylvania. What does this mean? "You can't use hormones to treat them. You're left with chemotherapy as your only option."

Age of Patient

Age plays a big role in patients' future fertility. "The age of the woman at the start of systemic chemotherapy is the biggest predictor of infertility," Barbierri tells WebMD. But why?

"If you're 30, your fertility is already declining. Add to that chemotherapy, and you tack on a few more years. We know that chemotherapy induces menopause, particularly with women over 40," Domcheck says.