3 drugs attack kidney cancer

Kidney cancer spreads throughout the body in a third of the cases.
ATLANTA (AP) -- For decades, it has been one of cancer's great mysteries: Why do about 4 percent of kidney tumors spontaneously disappear?
Doctors believed that if the immune system was defeating the cancer, treatments to boost it might help the others, but that hasn't worked very well. Now, three new drugs are displacing the immune system theory and attacking the disease in various ways.
A Pfizer drug, Sutent, prevented tumor growth twice as long as immune therapy did in a study of 750 people whose disease had spread beyond the kidney.
An experimental drug, Wyeth Pharmaceuticals' temsirolimus, performed even better, boosting survival -- not just delaying tumor growth -- in a study of 419 very ill patients with widely spread kidney cancer.
Fresh results
Today, fresh results are expected on a third drug -- Nexavar, made by Bayer and Onyx Pharmaceuticals Inc.
"Until just a few years ago, there were no promising drugs for kidney cancer," said Dr. Gary Hudes of Fox Chase Cancer Center in Philadelphia, who led the study on the Wyeth drug.
There still is no cure, "but these drugs can control the disease for a significant amount of time," and may offer more benefit when given earlier in the course of the disease, he said.
The drugs were discussed Sunday at a meeting in Atlanta of the American Society of Clinical Oncology.
About 39,000 new cases of kidney cancer and 12,800 deaths from it are expected in the United States this year. Smoking is the top risk factor. About one-third of cases spread throughout the body, a situation currently incurable.
Temsirolimus is part of a new generation of cancer drugs that, unlike chemotherapy, attack cancer in more precise ways.
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