The link between breast and ovarian cancer

Women diagnosed with breast cancer are at a higher risk for ovarian cancer. This means that in addition to making decisions around treatment type and location, women must consider what do to about their ovaries. Women who wish to have children face one set of questions, while women who are done with children but not yet menopausal face another.

Genetics and risk
Some of the reproductive risk factors for ovarian cancer can also affect breast cancer risk. The risk of ovarian cancer after breast cancer is highest in women with a family history of breast cancer.

About 5 to 10 percent of breast cancers and 10 to 15 of ovarian cancers are hereditary. These hereditary breast and ovarian cancers are caused by a mutation in the BRCA1 or BRCA2 genes. Approximately 30 percent of all breast and ovarian cancer cases are caused by these mutations.

Short- and long-term ovarian suppression
In premenopausal women, the ovaries make up most of the estrogen in the body. Since estrogen is fuel for growth of hormone-sensitive breast cancer, reducing the amount of estrogen in the body or blocking it may help reduce the risk of recurrence or a secondary cancer such as ovarian.

Ovarian suppression is one way to slow down or block the growth of estrogen production in the ovaries and stops women from having menstrual cycles,” says Dr. Igor Medic, a medical oncologist affiliated with Sharp Grossmont Hospital. “Ovarian suppression is an option only for women who have yet to enter menopause.”

Drug therapy
“Ovarian suppression drugs, such as Lupron or Zoladex, are given as injections and act by telling the brain to stop influencing ovaries to produce estrogen,” says Dr. Medic. “Occasionally, ovarian function can still be re-initiated despite these hormonal injections.”

“If ovarian suppression isn’t tolerated and if a woman is done or has no plans of having children, removing her ovaries is an option to ongoing injections,” he adds.

In most cases, once drug therapy stops, the body begins to make estrogen again and menstrual periods may resume. Women who plan to have children after breast cancer may prefer medical shutdown over surgical ovary removal.

Ovary-removal surgery
Women with BRCA mutations, who are considered “high risk” for breast and ovarian cancer, often consider ovary-removal surgery (oophorectomy) to stop the production of estrogen and progesterone. While this is considered aggressive treatment because it puts the body prematurely and permanently into menopause, it may be a good option for women who are done having children or for women who are at high risk for the cancer returning.

The decision to have the ovaries shut down or removed requires a lot of careful thought and discussion with a woman’s doctor and loved ones.

“The most important fact that women need to know about breast cancer is prevention,” says Dr. Medic. “This cannot be emphasized enough. Exercise, weight loss and healthy diet; avoidance of alcohol; and regular screening mammograms are mainstays of prevention.”