While treatments for pediatric cancers have largely been a success story, leading to a survival rate of above 80 percent, some of the lifesaving therapies have left female survivors with infertility problems in their adult years. But a study led by researchers at the Dana-Farber Cancer Institute and Brigham and Women’s Hospital provides a glimmer of hope for these women.
About two-thirds of those who seek treatment for infertility achieve a successful pregnancy, a rate similar to other infertility patients who have never had cancer, the study found.
“It’s a surprisingly good finding,” said study coauthor Dr. Lisa Diller, chief medical officer of Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. “For doctors who suspect that this type of infertility is untreatable, we now know that not to be the case.”
The researchers drew these conclusions after surveying more than 3,500 women — treated for leukemia, Hodgkin’s disease, and other cancers as children — who were trying to get pregnant. The findings were published Friday in the journal Lancet.
Infertility rates were, however, nearly 50 percent higher in the group of cancer survivors than among a control group of nearly 1,400 of their sisters: 13 percent of the survivors needed more than a year to become pregnant, compared with 8 percent of sisters. A class of chemotherapy drugs called alkylating agents have been associated with poor egg quality and low sperm counts in those treated.
Female cancer survivors who were treated with abdominal radiation were more likely than their siblings to have nonworking ovaries — or early menopause — requiring them to obtain a donor egg or embryo to achieve pregnancy.
But the study found that cancer survivors who made efforts to get pregnant had the same chances of giving birth as any other woman seeking infertility treatment. That’s likely because they attempted pregnancy at a younger age — mid- to late 20s — much younger than women in their late 30s or early 40s who are typically seen in fertility clinics.
“We would recommend for most women who had childhood cancers to see a fertility expert sooner rather than later,” Diller said, and to attempt pregnancy during peak fertile years in their 20s.
Laura Allaire, 32, went to see a Boston fertility specialist in her early 20s after experiencing irregular periods and being warned that the chemotherapy she had as an adolescent for Hodgkin’s disease would make it tougher to get pregnant. She opted, though, against the hormones that her doctor recommended to spur ovulation. “I had mixed feelings about hormones,” she said, because of the mood swings they caused in her friends.
Allaire, an oncology nurse who now lives in California, gave birth to her first daughter at age 28 after trying to get pregnant for less than a year. She gave birth two years later to another girl.
In one puzzling finding of the study, cancer survivors who sought out fertility specialists were less likely than their siblings to get hormones or other treatments to increase their chances of conception.
“We don’t know if they weren’t getting drugs because their doctors assumed they had untreatable problems or because the women themselves were more worried about taking fertility drugs after undergoing cancer treatments,” said study coauthor Dr. Elizabeth Ginsburg, a reproductive endocrinologist at Brigham and Women’s.
The study also didn’t address methods of preserving fertility before cancer treatments, such as egg freezing; now considered to have proven effectiveness, it was experimental when researchers surveyed participants 10 to 20 years ago.
Ginsburg said pediatric oncologists should be talking with children and their parents about fertility preservation techniques. Egg freezing costs about $10,000 and still isn’t routinely covered by insurance, though that’s likely to soon change since reproductive health organizations recently endorsed egg freezing to preserve fertility, she added.
Ovarian tissue freezing is an option for girls who haven’t yet gone through puberty, but it’s still very experimental and shouldn’t be performed outside of a research setting. Teenage boys, who can also experience infertility related to cancer treatments, can bank their sperm.
A nonprofit called fertilehope.org can help defray the cost of egg freezing or sperm banking for cancer patients, depending on financial need. Brigham and Women’s has a contract with the group, Ginsburg said, and it helps pay for fertility drugs for cancer survivors.