Last month, a large study in The Lancet Oncology found that about two thirds of female survivors who sought out fertility treatments as adults ultimately became pregnant — a rate of success that mirrored the rate among other infertile women. Other recent studies have found that many men who experience low sperm counts after pediatric cancer, a side effect in two thirds of boys who receive chemotherapy, can undergo procedures that harvest viable sperm, allowing them to father their own children. Doctors say that while there is no doubt that childhood cancer increases the likelihood of infertility, the ovaries and testes of young cancer patients may be more resilient than they had previously thought.
"When we see cancer survivors as adults, depending on how late they are in their reproductive years, radiation and chemotherapy tends to have a pretty suppressive effect on their future fertility," said Dr. Hal C. Danzer, a reproductive endocrinologist at the Southern California Reproductive Center. "But this speaks to the fact that the ovaries and sperm production are more resilient in young individuals. It's very encouraging."
But if fertility treatment is to be successful, time is of the essence. Normally, for example, women under 35 are encouraged to attempt getting pregnant for at least a year before seeing a fertility specialist. For those with a history of cancer, however, the new message should be, "Don't wait," said Dr. Lisa R. Diller, the chief medical officer of the Dana-Farber/Boston Children's Cancer and Blood Disorders Center.
"The ovaries after childhood cancer have taken a hit, and they are almost aging more quickly than someone of the same chronological age without cancer," said Dr. Diller, the lead author of the Lancet study. "In the setting of having had childhood cancer, if a woman is 25 and has been trying to conceive for six months, then I would say see a specialist."
Typically, childhood survivors tend not to address fertility issues until they are in a relationship and their treatment is many years behind them, said Dr. Aarati D. Didwania, the director of the STAR survivorship program at the Robert H. Lurie Comprehensive Cancer Center at Northwestern University.
"A lot of young women will come in and say, 'I'm married, we've been trying for six months, is this related to my treatment?' " she said.
Traditionally, the fertility discussion has involved finding out which cancer therapies patients received and what their hormonal status is like, so doctors can estimate their likelihood of being infertile. Then they can talk about their options, Dr. Didwania said, and whether they need to resort to things like surrogacy, using donor eggs and sperm, or adoption.
But the new goal in the field of cancer fertility, or oncofertility, is to be as proactive as possible, said Dr. Teresa K. Woodruff, chief of the division of fertility preservation at the Northwestern University Feinberg School of Medicine.
Oncologists are increasingly making a point of bringing up the subject of fertility at the time of diagnosis, discussing options like freezing eggs, sperm and embryos before treatment. In younger patients who have not gone through puberty, some fertility clinics offer the option of freezing ovarian and testicular tissue, which can be reimplanted when patients get older.
Studies show that up to two thirds of young patients are now counseled about fertility before starting their cancer treatment.
"Today 80 percent of kids will survive," Dr. Woodruff said. "Now that patients are thriving and have decades of life ahead of them, fertility is a high priority for them."
Image: Pregnant couple, via Shutterstock