Doctor Cites 43% Success Rate : Drug Claimed Effective Against Brain Tumors
Methotrexate, a drug that was used successfully to treat Sen. Edward Kennedy’s son for bone cancer, can cure up to 40% of patients with a type of brain tumor that kills nearly 5,000 Americans annually, a researcher says.
“The news is good for brain tumors,” said Dr. Isaac Djerassi, a cancer specialist at Philadelphia’s Mercy Catholic Medical Center. “They are unresponsive to other treatments, but appear to be exquisitely sensitive to Methotrexate.”
Djerassi, who presented his findings at the American Cancer Society’s science writers’ seminar, used the drug to treat 30 patients with astrocytoma, a cancer of the supporting tissues of the brain.
Seven of the 30 didn’t respond to the drug. Tumor size was reduced in eight others, but they died either because the cancer recurred or because their tumors were very large when they started treatment, Djerassi said.
However, the tumors disappeared in 11 of the patients, two of the patients are in partial remission and another two are progressing toward complete eradication of their tumors--a success rate of about 43%, he said.
Survival Rate
Four patients have survived three to 18 years after their tumors were diagnosed, and 1 1/2 to 17 years after treatment was halted, so Djerassi said he considers the treatment a cure.
Further research into the use of Methotrexate combined with other drugs and radiation therapy should make it possible to increase the cure rate to about 80%, Djerassi said.
Conventional chemotherapy usually is ineffective against brain tumors because internal barriers prevent most chemicals in blood from reaching the brain. Of the 5,000 Americans who develop astrocytomas each year, most die, Djerassi said.
About half of all fatal brain tumors are astrocytomas, he added.
Djerassi said he was able to use Methotrexate successfully because the patients were given such high doses that the chemical reached their brains.
However, such dosages also attack growing cells other than cancer, and would have killed the patients along with their tumors if the drug had been administered alone.
Folic Acid
Methotrexate kills cancer and other growing cells by replacing the folic acid they need to grow and divide, he said. He prevented the death of normal cells by giving the patients folic acid with hydrogen atoms attached to it.
The doses of this antidote were large enough to let normal cells survive but small enough to let the Methotrexate kill cancer cells without interference, he said.
Dr. Vincent T. DeVita Jr., director of the National Cancer Institute, expressed skepticism that doctors would be able to handle this delicate procedure to avoid harming patients.
Djerassi replied that even some deaths from improperly administered Methotrexate are preferable to the current high rate of death from brain tumors and that most young doctors are being trained to use the drug.
Methotrexate has been used in chemotherapy for 30 years and has been used successfully in treating certain blood, lymph and bone cancers. The drug was used successfully in 1973 to treat bone cancer in Edward M. Kennedy Jr., the son of the Massachusetts senator. The younger Kennedy did have to have his leg amputated but the cancer was successfully treated with the drug.
Last month, researchers in Boston reported that low doses of Methotrexate were used successfully to ease the pain and swelling of rheumatoid arthritis in victims not helped by other medications.
