Fertility Preservation May Not Increase Risk for Breast Cancer Recurrence, Death

Findings from a study comparing patients with breast cancer who underwent fertility preservation versus those who did not demonstrate that there was no significant difference in their risk for disease recurrence and mortality, pointing to the safety of fertility preservation for women interested in pregnancy after diagnosis.

“Results of this study provide much needed additional evidence of the safety of (fertility preservation) procedures in women with (breast cancer) and may influence current health care practice to the benefit of young women with (breast cancer) who wish to preserve their fertility,” the researchers wrote in the study published in JAMA Oncology. “Women diagnosed with (breast cancer) during their reproductive years should be referred, when interested, for fertility counseling and provided with the available information on safety of the procedures that are offered.”

The current standard for fertility preservation in patients with cancer is cryopreservation of embryos, oocytes (immature egg cells) or ovarian tissue. The living tissues are frozen until they are thawed and reintroduced to the healed body. This treatment may be preceded by controlled ovarian stimulation via a hormonal treatment with estradiol.

There are perceived risks to fertility preservation in patients with breast cancer. For example, some patients may fear a relapse after the cryopreserved cells are placed back in the body, or the potential for hormonal treatments to accelerate tumor growth and spread. However, the data from this study demonstrated no greater risk for women who pursue either hormonal or nonhormonal fertility preservation as opposed to those who do not move forward with fertility preservation treatments.

Researchers assessed data from 1,275 women diagnosed with breast cancer during their reproductive years, defined as the ages of 18 to 44.

Of the women in the study, 425 received fertility preservation treatments. Those who skipped fertility preservation were more likely to already have had at least one child and were slightly older.

Breast cancer survival rates were compared among women who underwent hormonal fertility preservation, those who underwent the procedure without hormonal treatment and women who did not move forward with fertility preservation. The five-year survival was 96% for women in the hormonal group, 93% of those in the nonhormonal group and 90% in women who did not undergo fertility preservation. At 10 years, survival was 88%, 90% and 81%, respectively.

Relapse-free survival (defined as the time after primary treatment has ended that a patient survives without any signs or symptoms of that cancer) was analyzed in 723 of the women in this study due to the availability of relevant data. In this subgroup, death or relapse occurred in 97 women unexposed to fertility preservation and 35 who underwent the procedure.

Although the findings from this study indicate marginally improved outcomes for the women who underwent fertility preservation, the study authors noted in the paper that the differences are not statistically significant after adjusting the data for particular patient characteristics. Of note, statistical significance refers to whether a difference between groups is considered “real” or by “chance.” The authors also wrote that there may have been some bias when women were referred to fertility clinics.

“A ‘healthy (fertility preservation) effect’ may explain improved long-term outcomes in women with a history of (fertility preservation) because those who feel healthier and appreciate their prognosis to be good may be more prone to opt for (fertility preservation) at the time of (breast cancer) diagnosis,” the study authors wrote.

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