Research may help protect fertility of women in cancer therapy

WASHINGTON - Women having cancer therapy may one day be able to avoid the ovary damage that often leaves them unable to bear children, researchers report.

Scientists studying chemical and radiation damage to mice cells report promising results when the action of the chemical ceramide was blocked. But they caution that considerable work is needed before the method could be used in humans.

Blocking ceramide preserved the fertility of eggs normally destroyed in cancer treatment, researchers report in the October issue of the journal Nature Medicine.

''This holds the promise of selectively preserving ovarian function and preventing this tragic side effect of the treatment of cancer,'' said Dr. Richard N. Kolesnick of Memorial Sloan-Kettering Cancer Center in New York.

''For the first time we have a promising prospect for a small molecule that could be given to women and girls undergoing cancer treatment to protect their ovaries,'' added Jonathan Tilly of Massachusetts General Hospital, the paper's senior author.

Tilly cautioned that tests have only been done in mice and that tests are under way to determine the treatment's effect on human ovary tissue that has been transplanted in mice.

''It's very difficult to put a time frame on,'' when the treatment could be available for humans, he said. ''We will push ahead as quickly as we can.''

In an accompanying news article about the findings, Robert F. Casper and Andrea J. Juriscova of the University of Toronto said the research was ''an innovative and exciting potential new treatment to prevent oocyte destruction after cancer treatment.'' Oocyte is the scientific term for the egg cells of mammals.

While the paper focuses on ovary damage caused by radiation, Tilly said in a telephone interview that similar protection also occurred in tests involving doxorubicin, a chemotherapy drug.

The researchers had earlier found that the death of the ovarian cells involved a series of chemicals, including ceramide. The conversion of a molecule in the body called sphingomyelin into ceramide by an enzyme sets off the death of several types of cells in response to chemotherapy or radiation therapy.

So the scientists conducted tests to see if blocking the sphingomyelin pathway by using the compound sphingosine-1-phosphate would protect the eggs in live animals.

They injected S1P into the sac surrounding one ovary in each of a group of normal mice and then exposed them to a dose of radiation that would be expected to destroy most of their eggs.

Two weeks later the ovaries receiving S1P appeared healthy while the unprotected ovaries showed almost complete destruction of eggs.

''There was absolutely no damage at all that we could see,'' in the ovaries with S1P, Tilly said. ''The ovaries looked normal ... the mice were cycling normally, they ovulated and were able to produce embryos. By all criteria they were normal.''