ASCO 2014: Simple step could protect fertility for women treated for some breast cancers

May 30, 2014 | by

Preserving fertility is an important and common concern among young women who are diagnosed with cancer. New study findings offer women a simple new option for treating hormone receptor-negative breast cancer and protecting their fertility.

Women at an elevated risk of developing breast cancer, should be offered drugs, such as tamoxifen or raloxifene, to reduce that risk, the U.S. Preventive Services Task Force suggests.

A Cleveland Clinic study presented at ASCO found that adding a hormone-suppressing drug to chemotherapy treatment protected fertility and increased survival among women with hormone receptor-negative breast cancer.

The study, presented at the 2014 Annual Meeting of the American Society of Clinical Oncology in Chicago, suggests adding a hormone suppressing drug called goserelin (trade name Zoladex) to standard chemotherapy may be an effective method of preserving fertility for those women with early-stage breast cancer that is hormone receptor-negative.

In the Cleveland Clinic study, women who received the drug along with chemotherapy were 64 percent less likely to develop premature ovarian failure compared to women who received chemotherapy alone. Further, the study found, they were also more likely to have successful pregnancies. The study also found a surprising survival benefit: Those women who took goserelin were 50 percent more likely to be alive four years after starting chemotherapy than those who took the standard treatment.

"This is a really important trial for young women with hormone-independent breast cancer because they now have the option of taking goserelin – an LHRH agonist therapy – to preserve their fertility,” said Joanne Mortimer, M.D., director of the Women’s Cancers Programs at City of Hope, who was not involved in the study. “Although there were problems accruing the number of patients the researchers had hoped for, there were still enough data that women on this therapy were more likely to have children. Additionally, one of the more interesting findings of this study is that women on LHRH agonist therapy had a longer disease-free survival, which we wouldn’t expect for women with hormone-independent breast cancer.”

Ovarian failure is a common side effect of chemotherapy, and risk of ovarian failure varies depending on the type and dose of chemotherapy as well as a patient’s age. Goserelin, and other lutenizing hormone-releasing hormone analogs, can temporarily stop the ovaries from functioning – putting the patient into a postmenopausal state. Researchers speculated this protects the eggs from chemotherapy damage. These medications are commonly used to control ovulation timing for in vitro fertilization and other fertility procedures, and they’re also used to treat advanced prostate and breast cancers.

The study included 257 women with early stage hormone receptor-negative breast cancer, and were randomized to treatment with chemotherapy alone or chemotherapy with the hormone suppressing drug. Two years after starting chemotherapy, 8 percent of women who took goserelin had ovarian failure, compared to 22 percent of women in the standard arm.

The abstract (#LBA505) is available on ASCO’s website.

Learn more about breast cancer treatments available at City of Hope.