October 21, 1998
Web posted at: 10:36 p.m. EDT (0236 GMT)

A new bone marrow transplant technique may improve the chances of survival in cancer victims who cannot find good tissue matches with donors.

According to doctors from the University of Perugia in Italy and the Weizmann Institute in Israel, the new method offers the chance of a successful transplant using only partially matched donors.

Bone marrow transplants are often the only lifesaving treatment for patients with leukemia and lymphoma who don't respond well to chemotherapy and other treatments.

But transplants often fail without a good match of tissue types, when the patient's own body attacks the new, foreign marrow.

Now doctors hope to avoid that obstacle by giving donors much larger than usual doses of donated marrow.

Donors given growth hormone

In a new method reported in Thursday's New England Journal of Medicine, donors are given a growth hormone that causes the release of large numbers of marrow cells into the bloodstream.

Those marrow cells are then strained from the donor's blood and cleansed to remove blood cells that could cause the patient's immune system to reject the new marrow.

After 18 months, 12 of the 43 patients treated with the partially matched donor transplants were free of disease, offering hope for patients who can't find good matches.

New method could help certain ethnic groups most

About 25 percent of patients seeking transplants find near-identical matches through family members. Others must seek a donor in the worldwide registry, and 80 percent of those eventually do find a match, leaving 20 percent without any hopes of a donor.

For some patients the odds are even worse.

"Ethnic subgroups such as African-Americans, Hispanic- Americans and Chinese-Americans are greatly underrepresented in those donor pools," said Dr. Joseph McGuirk, a bone marrow transplant specialist at Yale University Cancer Center.

Using the new technique with partially matched donors could help solve that problem.

Yale-New Haven hospital in Connecticut is one of the few places using the new method. It has already shown remarkable success among leukemia patients.

"With the mismatch transplants in patients with high-risk leukemia such as relapsed leukemia or leukemia that's resistant to all types of chemotherapy, they were saving approximately 40% of those patients," said McGuirk.

CNN Medical Correspondent Dr. Steve Salvatore and The Associated Press contributed to this report.