Egg freezing may not delay chemo for breast cancer patients

Women diagnosed with breast cancer who want to freeze their eggs and embryos before tumor treatment leads to infertility can do this without delaying the start of chemotherapy, a U.S. study suggests.

Researchers focused on 89 women newly diagnosed with breast cancer who received counseling at a fertility clinic about a relatively new technique known as random-start ovarian stimulation. This process doesn’t wait for a woman’s natural menstrual cycle to stimulate the ovaries to release eggs and can be done in about two weeks, compared with four to six weeks with older ovarian stimulation techniques timed to coincide with menstruation.

Overall, 67 of the women proceeded with random-start ovarian stimulation before beginning cancer treatment. With fertility treatment, women started chemotherapy an average of 38 days after their breast cancer diagnosis, compared with 39 days when patients decided against fertility preservation. “What this tells us is these women can still go on to build a family,” said senior study author Dr. Mitchell Rosen, a reproductive health researcher at the University of California San Francisco. “It only takes two weeks, and it isn’t going to cause any delay in their cancer treatment,” Rosen said in a telephone interview. When chemotherapy is needed soon after a breast cancer diagnosis, doctors generally advise that it begin within four to six weeks to avoid hurting women’s survival odds. Chemotherapy can cause infertility by damaging the ovaries and by triggering an early menopause in women of childbearing age.

For the study, researchers examined data from medical records for breast cancer patients between the ages of 18 and 45 who were referred to the UCSF Center for Reproductive Health between 2011 and 2017 before starting chemotherapy. Women started chemotherapy at roughly the same time whether or not they decided to first harvest eggs and freeze eggs or embryos, researchers report in Human Reproduction. One limitation of the study is that it didn’t look at other reasons beyond fertility preservation that might influence how long it takes for women to start chemotherapy, such as tests to pinpoint the type of tumors imaging to find out how far cancer has spread or patients making arrangements to take time off of work or prepare their lives for chemo.

The study also wasn’t a controlled experiment designed to prove how fertility preservation directly influences the time it takes to start chemotherapy, and the results from one fertility center might not represent what all women would experience. Even so, the findings suggest that random-start ovarian stimulation may be a viable option for women with breast cancer or other types of malignancies who don’t want to lose their ability to have children after tumors are in remission, said Dr. Kutluk Oktay, director of the Innovation Institute for Fertility Preservation and IVF in New York and a researcher at Yale University School of Medicine in New Haven, Connecticut.

“With this approach, a patient can be started on ovarian stimulation even on the day of the initial consultation and can be done with embryo or egg freezing in two weeks,” Oktay, who wasn’t involved in the study, said by email. “And if she has more time, she can even do multiple cycles of freezing without risking a delay in chemotherapy,” Oktay said. “Random start extends all women who are considering embryo or egg freezing before chemotherapy for any type of cancer more flexibility and ability to preserve fertility with the least delay before initiating ovary damaging cancer treatments.”