Saving Fertility of Kids With CancerMonica Bielanko
9-year-old Dylan Hanlon has cancer. A lump in his chest turned out to be Ewing’s sarcoma, a rare cancer, fortunately caught early.
The prescribed nine months of chemotherapy doctors are using to destroy the cancer may also be destroying his chances of fathering his own children when he grows up. Numerous forms of chemotherapy, high-dose body-wide radiation, radiation aimed at the pelvis and some surgeries can leave patients unable to procreate.
About 10 percent of the 1.5 million people diagnosed with cancer last year were younger than 45, more than 15,000 of them under 20. It’s estimated that roughly half of younger patients risk either some immediate fertility damage, or for girls the prospect of menopause in their 20s or 30s. It depends on the type of cancer and treatment. Young adults have options — bank some sperm, freeze embryos or eggs. Children diagnosed before puberty don’t. Boys don’t produce sperm before puberty, ruling out sperm banking. Girls are born with all the eggs they’ll ever have but those are in an immature state, so egg-freezing isn’t an option.
With childhood cancer survival reaching 80 percent, there’s a growing need to find ways to preserve these youngsters’ fertility. Dylan’s mother, Christine, says doctors didn’t make the fertility risk clear and has tracked down an experiment that could save Dylan’s future fertility.
“There are viable options, and they are on the doorstep,” says Dr. Kyle Orwig of the University of Pittsburgh. He oversees a multi-hospital program called Fertility Preservation in Pittsburgh and leads the study Dylan joined to store the stem cells boys harbor that later on will produce their sperm. The idea is to eventually transplant the cells back.
Orwig and other researchers have restored fertility in a range of male animals — mice, rats, pigs, dogs — by storing and reimplanting sperm-producing stem cells.
Researchers say several dozen boys and girls, including some babies, so far are part of these early-stage experiments at a handful of medical centers.
Testing the technique in boys requires biopsy-style removal of a small amount of testicular tissue. No one knows how many stem cells are floating among the millions of other cells frozen from that sample, or how many are necessary. But Orwig says the more tissue collected, the better.
Most of his sample was frozen, for Dylan’s later use if he wants it. The rest went to Orwig’s lab for research — and two weeks later came the good news that Dylan’s tissue indeed harbored stem cells despite a few months of chemo. Key to this approach will be multiplying stored stem cells so that many more can be injected back.
Girls pose a different challenge. Some young women have had strips of their ovaries removed and frozen before cancer treatment, and then transplanted back a few years later. It’s considered experimental even for adults, with 13 births reported worldwide so far, says Northwestern’s Woodruff. Dr. Teresa Woodruff of Northwestern University’s Oncofertility Consortium, who works with girls’ ovarian tissue. “If we protect their fertility now as a 9-year-old, we hope … that tissue we’ve guarded can be used” when they’re grown.
Now researchers are banking the same tissue from girls. It requires laparoscopic surgery. Storing enough isn’t the issue: Egg follicles are progressively lost through life, so a girl harbors more than even a 20-something, Woodruff says. A bigger unknown is how long they can be frozen.
Also, there’s a possibility cancer cells could lurk in frozen tissue. So Woodruff is going the next step, researching ways to force those stored follicles to ripen into pure eggs in a lab dish.
However the different experiments pan out, Dylan’s mother says more families should be told about them: “Doctors should have this information, have it there to give to the parents. Let the parents decide.”
For more information:
University of Pittsburgh cancer fertility program: http://www.mwrif.org/220