Cancer treatments like chemo and radiation therapy, while lifesavers, can have significant side effects. One possible side effect that can be devastating for patients is the loss of fertility.
The Oncofertility Consortium at Northwestern University is working to preserve fertility for women undergoing cancer treatment by freezing ovarian tissue and researching ways to later recover ovarian follicles (an egg and its supporting tissue) in the hopes of using them for in vitro fertilization.
Min Xu, research assistant professor of obstetrics and gynecology at Northwestern, has been working with the Consortium for six years. He sat down with Medill Reports to answer a few questions.
What are the types of cancer treatments that can lead to fertility loss?
The short answer is not all treatments can cause you to lose your fertility. It depends on which kind of chemo medicine you are using, how long you are going to use it, which dose you are going to use and if you are going to use radiation therapy.
Do different types of cancer have different risks of causing fertility problems?
With some [types of cancer], like pelvic cancers, [that require] radiation treatment, you have a high risk, [because] the ovaries sit on the pelvis.
The other treatment that pretty much guarantees [fertility loss] is a bone marrow transplantation. If people have leukemia or another disease and have to go through radiation and chemotherapy, both of those can totally destroy germ (sex) cells. For those people, they pretty much need fertility preservation to have babies in the future.
I assume that preserving fertility is more difficult when the cancer patient is a child. Has there been any success with young patients?
That depends on how young. I don’t know how many cases, but we do have some teenagers. I think the youngest one is eleven.
Right now the problem is we don’t really know whether it works or not. Most [ovarian tissues] are coming from young women, like mid-20s to 30s. They have a demand to have babies. For kids, I don’t think [they] will have a demand to use [their] ovaries for 10, 15 or 20 years.
So it’s not harder to use ovaries from a young patient in the future?
Well, it’s harder for kids, but it’s not because of a technical thing, it’s more because of social issues. How do you make a decision for the young kids? Who is going to make the decision? How much does she (the patient) know about fertility? So you have to talk to her parents. Technically, you should really do this when you are young, [because] you have more eggs.
How long do you think it will be before fertility can be easily preserved in humans?
That’s a hard question; I don’t want to make predictions. It could be tomorrow, it could be ten years later. The basic research on it is very interdisciplinary. Maybe one kind of technological development, maybe in another field, could solve a lot of problems.
What are some of the challenges you are facing in trying to apply the research you have done on mice to humans?
There are several challenges. The first challenge is mice are mice and humans are humans. They share a lot of similarities, but they are two different species, so no matter how successful you were on mice, you have to prove it in humans. In order to prove it in humans you have to get human tissues. Where to get live human ovarian tissue is the major challenge right now, because it’s not like blood or sperm, people can’t just donate.
Another problem is that this is a new field. When people are facing cancer, the number-one priority is [saving lives] for most oncologists. So I think when they start talking to their patients, they are going to pay more attention to how they are going to save their lives. With 30 minutes of talking with your oncologist, how much can really be covered?