Effects of Chemotherapy on Fertility May Be Underestimated Significantly

Many cancer survivors who thought they were fertile now may be finding that is not the case. New research is suggesting that current estimates of the impact of chemotherapy on women’s reproductive health are too low.

Researchers at the University of California San Francisco (UCSF) say their analysis of the age-specific, longterm effects of chemotherapy provides new insights that will help patients and clinicians make more informed decisions about future reproductive options, such as egg harvesting (Cancer. September 1, 2011. Epub ahead of print).

The investigators adopted a more tailored investigation into chemotherapyrelated infertility and found estimates may have been far too low. They say these findings will now change how oncology nurses counsel their patients. “The nurses play a pivotal role here,” said study investigator Mitchell Rosen, MD, assistant professor in the UCSF Depart ment of Obstetrics, Gynecology and Reproductive Sciences. “Nurses are the most important. Most of the time, referrals are generated and initiated by the nurse.”

He said that oncology nurses need to be aware of the new study findings and consider them when educating patients. Rosen said even though an oncologist mentions that fertility may be affected, many patients simply don’t comprehend fully what that means because they are focused more on their current treatment options to enhance survival. “They forget about the one sentence from the oncologist,” said Rosen in an interview with The Oncology Nurse-APN/PA. “I think everyone who is taking care of patients diagnosed with cancer needs to be educated about it. There are still not enough referrals going to the fertility specialists. The more awareness we can do, and the more people that are involved, the better.”

He said many men and women undergoing chemotherapy are not getting enough information about how their future fertility may be affected by the various treatments they may be receiving. “At every center there is a difference in who is involved when a patient is getting treated, so the more [nurses] are involved the better. It needs to be standard of care for both men and women. Only 10% to 30% of men bank sperm, and that is easy. It is much more complicated with women. Yet 10% to 30% do it, and the main reason for [the low numbers] is a lack of education and awareness,” said Rosen.

Previous studies largely have focused on amenorrhea, the lack of menstruation shortly after treatment, as the primary reproductive side effect of chemotherapy. Analyzing retrospective survey responses from women who were diagnosed between 18 and 40 years, the researchers focused on longer-term, age-specific outcomes associated with chemotherapy, including infertility and early menopause. Their analysis suggests that the younger a woman is when diagnosed with cancer, the more likely she will experience early menopause. “We found chemo therapy essentially narrows a woman’s reproductive window by causing a range of damage to the ovaries, even if her menses resume after chemotherapy,” said Rosen.

Many of the women who responded to the survey had been told that as long as their periods returned, they would have no negative impact from treatment, he said. Making recommendations on preserving fertility currently is based on rather limited data. These new findings, which also take into account cancer type and age, hopefully will enable clinicians to offer more strategic and personalized counseling.

The researchers used the California Cancer Registry (a statewide population based cancer surveillance system) to ask women about their reproductive history before and after cancer treatment. Survey questions addressed acute ovarian failure (cessation of menses after treatment), early menopause (meno pause before 45 years of age), and infertility (failed conception).

A total of 1041 women diagnosed with 1 of 5 targeted cancers (leukemia, Hodgkin disease, non-Hodgkin lymphoma, breast cancer, and gastrointestinal cancers) between the ages of 18 and 40 years responded, and 620 reported having been treated with only chemotherapy.

The researchers found the percentage of women reporting acute ovarian failure was 8% (Hodgkin disease), 10% (non- Hodgkin lymphoma), 9% (breast cancer), and 5% (gastrointestinal cancers). In women without acute ovarian failure, the incidence of infertility increased significantly with age at diagnosis.

In addition, the estimated probability of early menopause increased significantly with younger age at diagnosis. When counseling patients, focusing solely on short-term outcomes like loss of menses may give women unrealistically low assessments of their risks, because they could experience infertility or early menopause years to decades after treatment. Rosen noted that more research is needed because this study did not include genetics or variations in individual cancer treatments.