Battling cancer is traumatic enough without worrying about whether chemotherapy will prove toxic, but that's the added risk facing a minority of cancer patients.
Standard doses of chemotherapy -- often effective in treating various solid tumors -- sometimes kill people whose livers cannot clear the drug at the normal rate. Doctors can't tell beforehand which patients might have trouble with the treatment.
Now, a new study shows a relatively simple technique pioneered by a University of North Carolina at Chapel Hill, physician can distinguish between patients who metabolize one anti-cancer drug normally and those who need to receive lower doses for safety. Researchers say the approach might work for other chemotherapy agents and perhaps other non-cancer drug treatments as well.
"When you take a drug like aspirin or Tylenol, the reason you need to take it again in four to six hours is that your body has chewed it up and gotten rid of it through a certain chemical pathway in the liver," said Dr. Paul B. Watkins, professor of medicine and director of the Verne S. Caviness General Clinical Research Center at the UNC-CH School of Medicine. "Because of diet, genetics and other factors, some people just metabolize drugs a lot more slowly. As a result, the recommended dose of many chemotherapies will predictably make about 10 percent of patients very ill, and 1 or 2 percent of patients may die as a direct result of the treatment."
Conversely, patients whose livers clear a given chemotherapy rapidly may not get a dose strong enough to be effective against their cancer, he said.
A report on the new study appears in the April issue of Clinical Cancer Research, a medical journal that has just been released. Besides Watkins, authors include Drs. JoAnn Hirth, Myla Strawerman, Anne Schott and Laurence Baker of the University of Michigan.
Investigators took blood samples from 21 cancer patients several times over 24 hours to determine how fast t
Contact: David Williamson
University of North Carolina at Chapel Hill