Experts prefer to call the treatment "non-ablative bone marrow transplant." Before a normal BMT, patients get high-dose chemotherapy that kills off all the blood cells in the bone marrow. Mini-BMT uses just enough chemotherapy to create room for the transplant. The transplanted stem cells then partner with existing bone marrow cells to fight cancer.
Five to nine years after undergoing mini-BMT, four out of five patients were still in complete remission of their cancer. The two patients who relapsed underwent further treatment and are both now in sustained remission.
"I truly believe this is curing patients," Issa Khouri, MD, M.D. Anderson professor of stem cell transplantation, tells WebMD. "It is the only treatment out there where the 'cure' word can be used."
That's not an overstatement, says Gordon Phillips, MD, director of the blood and marrow transplant program at the University of Rochester, N.Y.
"It is a reasonable statement, although it remains a little bit controversial," Phillips tells WebMD.
Phillips notes that the cure rate seen in the study likely reflects that the patients were highly selected -- all, for example, had chemotherapy-sensitive tumors -- and that follicular lymphoma may be more amenable to mini-BMT treatment than other non-Hodgkin's lymphomas.
Even so, Phillips says, other cancer centers are getting roughly similar results with the technique. He notes that Kouri's colleague, Richard Champlin, MD, is one of the pioneers of the mini-BMT technique.
The treatment calls for two or more rounds of combination chemotherapy at levels that might be used in patients not getting transplants. The regimen includes a new biological cancer treatment called Rituxan. It's followed by an infusion of bone marrow cells from matched, usually unrelated donors.
Immunity-suppressing treatment is given to keep the body from rejecting the transplants. The idea is to get the new cells to attack the tumor. The problem is to avoid having the new cells attack the body -- a phenomenon known as graft versus host disease or GVHD.
More than half of the patients did suffer some form of GVHD. This usually requires treatment with immune-suppressive therapy. Khouri says Rituxan treatment helped many of these patients. Only five of the original 47 patients were still receiving immune-suppressive treatment at their last checkup.
"The most intense GVHD we saw in only 11% of patients -- and only 3% had the most severe form," Khouri says. "So this is a huge improvement in GVHD over traditional BMT."
Which patients need mini-BMT?
Phillips notes that first-line treatment for non-Hodgkin's lymphoma does not include any form of BMT. Most patients achieve a cure without such drastic therapy.
"But for patients who have had primary therapy and it hasn't worked too well, those patients are candidates for stem cell transplants if they are in good general health," Phillips says. "And the good news these days is that there is no need for a sibling donor. Even with an unrelated matched donor, those results are almost as good as with a sibling."
Khouri reported the new findings at the annual meeting of the American Society for Hematology, held Dec. 8-11 in Atlanta.