Anemia Drug May Hurt Cancer Treatment
Worse Survival, Cancer Control Seen With Cancer-Related Anemia Drug
Oct. 17, 2003 -- Treatments for cancer-related anemia may actually worsen cancer survival in some patients, say researchers.
However, experts offer caution in interpreting these study results, which appear in the Oct. 18 issue of The Lancet. They point out several problems with the study that could have led to misleading results as well as the inability to extrapolate these findings to other cancers and clinical situations.
In addition to improving cancer-related anemia, these drugs were thought to possibly improve cancer survival by improving response to chemotherapy and radiation.
The researchers wanted to test whether treating cancer-related anemia in patients receiving radiation therapy would improve delivery of oxygen to the body and make treatments more effective, but it didn't, lead researcher Michael Henke, MD, tells WebMD. He is vice chairman of radiation oncology at the University of Freiburg in Germany.
Similar Drugs, Different Effects
The drug in the study -- called epoetin beta -- is similar to but not exactly the same as two other drugs used for cancer-related anemia in the U.S. Currently available treatments are Epogen and Procrit -- known generically as epoetin alfa. These drugs work by increasing production of oxygen-carrying red blood cells. Manufacturer Hoffmann-La Roche supplied the drug used in this study.
In the study, conducted in Austria, Germany, France, and Switzerland, 351 patients receiving radiation therapy for mouth and throat cancers were given either epoetin beta or a placebo.
The researchers found that epoetin beta corrected cancer-related anemia in patients undergoing radiation therapy for mouth and throat cancers. However, it did not improve cancer control or survival.
In fact, Henke says, the drug appeared to worsen cancer control in these patients. Compared with the placebo group, patients receiving epoetin beta were 62% more likely to have progression of their cancer and die.
"These findings are intriguing, concerning, and surprising," Douglas Rizzo, MD, associate professor of hematology/oncology at the Medical College of Wisconsin in Milwaukee, tells WebMD.
But he has some concerns about how the researchers presented their study results. For example, even though about 350 patients were enrolled in the study, results were presented only for about 150 patients because the others were not treated according to study protocol. Rizzo notes that this makes it difficult to fully understand what the study is telling us.
Despite this and other concerns, Rizzo concludes that "I think it's likely or at least possible that these findings are true."
But why would the results of this trial differ from those of previous studies suggesting benefits of drugs for cancer-related anemia beyond its effect on anemia?
Henke cites differences in how earlier studies were done compared with this newer, more powerful study. In addition, many previous studies looked at quality of life rather than survival or cancer control, he says.