Within a year, if all goes well, the first cancer patient will be injected with two new drugs that can eradicate any type of cancer, with no obvious side effects and no drug resistance - in mice.

Some cancer researchers say the drugs are the most exciting treatment that they have ever seen. But then they temper their enthusiasm with caution, noting that the history of cancer treatments is full of high expectations followed by dashed hopes when drugs with remarkable effects in animals are tested in people.Still, the National Cancer Institute has made the drugs their top priority, said Dr. Richard Klausner, the director. Klausner called them "the single most exciting thing on the horizon" for the treatment of cancer.

"I am putting nothing on higher priority than getting this into clinical trials," Klausner said. The mouse studies are "remarkable and wonderful," he said, and "very compelling." But he pointed out that the studies were in mice and so, in humans, he said he wanted to emphasize "the if's."

The new drugs, angiostatin and endostatin, work by interfering with the blood supply tumors need. Given together, they make tumors disappear and not return.

Dr. James Pluda, who is directing the cancer institute's planned tests of the drugs in patients, said he and others at the institute were electrified when they heard the drug's discoverer deliver a lecture about the newest results. "People were almost overwhelmed," Pluda said. "The data were remarkable."

Although the discovery of the drugs, and some of their effects, have been reported over the past few years, Pluda said that "if people understood how many steps ahead" the research was compared to what had been published, "they'd be even more in awe."

But Dr. Jerome Groopman, a cancer researcher at the Harvard Medical School, was wary. "We are all driven by hope," he said. "But a sober scientist waits for the data." And until the drugs are given to humans, he said, the crucial data simply do not exist.

So far, the drugs are the only ones ever tested that can seemingly eradicate all tumors in mice, even gigantic ones, equivalent to a two-pound growth in a person. The best that other cancer drugs have done is slow the growth of these large tumors. Mice are the traditional test animals in cancer research.

But even the drugs' discoverer, Dr. Judah Folkman, a cancer researcher at Children's Hospital in Boston, is cautious about the drugs' promise. Until patients take them, he said, it is dangerous to make predictions. All he knows for sure, Folkman said, is that "if you have cancer and you are a mouse, we can take good care of you."