Breast cancer drug study produces surprising flip-flop

Final results from a big study comparing two drugs for preventing breast cancer in high-risk women reveal surprises that challenge the government's claim that one is clearly better.

Photo: Breast cancer drug study produces surprising flip-flop

The study compared the old standby, tamoxifen, to raloxifene, a newer drug so far approved only for preventing the bone disease osteoporosis. The government contends raloxifene is safer.

At a news conference in April, the National Cancer Institute, which paid for the $88 million (Ђ67.91 million) study, said both drugs were equally effective at lowering the risk of serious forms of breast cancer. But raloxifene users had 36 percent fewer uterine cancers and 29 percent fewer blood clots, making it a safer choice, government researchers said.

However, data made public on Monday show that the uterine cancer results were not statistically significant. This means the actual number of cases differed so little that they could have happened by chance.

Scientific standards have long held that such results only suggest trends and are not definitive, certainly not to the extent that government scientists portrayed them to be.

Furthermore, so few blood clots occurred in the study that some doctors don't believe that result proves raloxifene is better. Also, it isn't known whether raloxifene's cancer-prevention benefit will last years after women stop taking the pills, as tamoxifen's is known to do.

"There is some genuine controversy here," said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society. Not everyone agrees "that there was a clear winner in this study," he said, reports AP.

According to Bloomberg, new drugs from Pfizer Inc. and Wyeth, given as initial treatments for advanced kidney cancer, may help patients live longer, two large international studies show.

Pfizer's Sutent, approved in January and shown to help people who fail a first therapy, slowed the cancer's growth more than standard care, researchers said. Wyeth's experimental drug temsirolimus helped patients with the most severe disease live longer with few side effects, the second study found.

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 different ways.

"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, reports Houston Chronicle.

O.Ch.