The medication is already used to treat patients who have failed other treatments, but doctors didn't know if it would work earlier and let patients avoid the trauma of chemotherapy by injection. "This is one more step in the right direction," says Dr. Vincent Rajkumar, a blood doctor and cancer specialist at the Mayo Clinic and the study's lead researcher. "But the big breakthrough would be if we found a cure, which this is not."
Multiple myeloma is fairly rare -- it accounts for only 1 percent of all cancer cases -- but it is especially deadly. The disease is difficult to treat, partly because the cancerous cells are not in one place but instead spread throughout the body's bone marrow. About 14,000 cases are diagnosed each year, and 11,000 patients will die.
Chemotherapy is a common treatment, but studies in recent years have also supported the use of thalidomide, which was used as an insomnia cure and morning sickness aid in the 1950s. Researchers discovered too late that the drug could cause severe birth defects in unborn children, and the federal government now approves its use only in cases of leprosy.
Doctors can use drugs for so-called "off label" purposes, however, and doctors frequently prescribe thalidomide for patients with advanced cases of multiple myeloma.
The drug appears to work by shutting off blood vessels that feed cancerous cells. A similar process may have prevented the proper growth of fetuses in pregnant women in the 1950s, Rajkumar says.
But the true workings of thalidomide are unknown because it's extremely difficult to study the drug either in the laboratory or in people. "It's become anybody's guess as to what the process is," he adds.
In his study, Rajkumar and colleagues gave thalidomide and the chemotherapy drug dexamethasone to 50 patients in the early stages of multiple myeloma. The findings appear in tomorrow's issue of the Journal of Clinical Oncology.
Thirty-two of the patients (64 percent) showed major improvement. Tests showed the cancer in their bodies shrank by at least 50 percent, Rajkumar says.
"That's very good and compares to most aggressive chemotherapy drugs," he notes.
One of the biggest benefits of the drug regimen is that patients can take the medications by mouth without going through the debilitating side effects of chemotherapy such as nausea and hair loss, he says.
By adjusting the dosage, doctors reduced the risk of major skin infections, a problem that had hampered earlier research into the drug's use, he says.
Rajkumar emphasized that the treatment doesn't cure multiple myeloma, but instead makes patients a better risk for the next step in the process, the re-transplantation of the body's own bone marrow cells, he says.
While the new study suggests the drug combination works, it doesn't prove it because it's difficult to compare the subjects with patients who never received the treatment, Rajkumar says. The Mayo Clinic is already working on new studies that will compare groups of patients -- some who will get the drug and some who won't -- to each other.
"One must be cautious not to consider this the standard of care at this time," says Dr. Omar R. Kayaleh, an oncologist at the M.D. Anderson Cancer Center in Orlando, Fla.
However, Kayaleh says the results are promising and a "good step in the right direction of providing new options for patients."
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