There are nearly half a million cancer survivors of reproductive age in the U.S., and new research finds that very few of them are taking steps to make sure they will retain the option of having children before starting treatment.

The study -- which focuses specifically on young women -- also reveals sweeping racial, economic and demographic gaps in terms of which women have access to fertility preservation services, as well as who gets counseled about the possible long-term effects on fertility in the first place. (According to the National Cancer Institute, radiation therapy and chemotherapy agents can damage immature eggs, impact the body's hormonal balance or result in injuries to the reproductive organs.)

"Let's say you're diagnosed with breast cancer. Your doctor might say, 'The treatment might affect your fertility, but let's figure out how we're going to go ahead and save your life,'" said Dr. Mitchell Rosen, director of the University of California at San Francisco's Fertility Preservation Program and an author on the study.

"That brief sentence might be considered counseling -- and the depth of your counseling can have a real impact on your quality of life as a survivor," he added.

In the new study, published Monday in the journal Cancer, more than 1,400 women age 18 to 40 answered questions about their health and history. The women had several different types of cancer: leukemia, Hodgkin disease, non-Hodgkin lymphoma, breast cancer and gastrointestinal cancer.

Overall, 61 percent of respondents said their oncologists had counseled them on the possible risks that cancer treatments posed to their future fertility.

This, according to the researchers, represents an increase in the prevalence of counseling in the U.S. -- an increase that may be a result of American Society of Clinical Oncology [ASCO] recommendations that all women be offered reproductive counseling before beginning cancer therapy. Those guidelines were issued in 2006.

Nonetheless, the new research still uncovers significant gaps between those women who were told about possible infertility and those who weren't: Those who had gone to college were 20 percent more likely to be counseled than those who had not.

Women who were childless, younger, white and heterosexual were also more likely to be told about the possible effects of cancer treatments on their ability to conceive.

"Fertility preservation is kind of in no-man's land, so to speak, because it's a hybrid between the cancer and infertility fields," said Dr. Kutluk Okay, co-chair of the panel that developed the ASCO guidelines, which it is currently revising in light of studies like the Cancer one. It expects to release the updated guidelines in the next year or so.

"On the cancer side, there's no official training for this," Okay added, while explaining that some institutions have started pilot programs that train nurses to discuss women's options with them before their treatments begin.

But the new study also finds that while more than half of respondents had been told about possible infertility stemming from their cancer therapies, only 4 percent actually took steps to save their eggs or embryos.

This is up from 1993, when estimates suggest that 1 percent of women took such steps, but down from 2005 to 2007 when between 6 percent and 10 percent of women moved to preserve their fertility.

One major obstacle, Rosen said, is cost.

Very few, if any, insurers cover fertility preservation for men and women undergoing cancer treatments, although Rosen pointed to a bill in Sacramento, Calif., that would be the first in the nation to require insurers to provide fertility options for patients of childbearing age. According to the study's authors, the total cost of retrieving and/or producing embryos and then freezing them is between $8,000 and $24,000.

The upside, the authors write, is that the cancer treatments available in the U.S. have improved significantly, which means survival is a reality for more and more patients. This means, however, that health care providers must focus more closely on counseling patients about fertility preservation, particularly in light of the current disparities that exist.

"It can be a double blow. First, you get diagnosed with cancer all of a sudden, then you survive, you get through it all and you suffer from infertility," Rosen said. "We're getting good at saving lives. Now, we have an obligation to make sure that the quality of life is as high as it can possibly be as a survivor."