Serious side effects more likely in new cancer drugs
By Genevra Pittman
NEW YORK (Reuters Health) - Many new cancer drugs may come at a price - including a higher risk of diarrhea, skin problems and high blood pressure, according to an analysis of studies used to get those medications approved.
Researchers said patients should know that serious side effects - or toxicities - with newer chemotherapy or targeted cancer drugs might be "unusual" - and they should discuss anything that doesn't seem right with their doctor.
For their analysis, Canadian researchers used reports on 38 cancer drugs reviewed and approved by the U.S. Food and Drug Administration between 2000 and 2010. Those included medications to treat colon, breast and lung cancers.
The study showed the newer cancer drugs caused significantly more side effects, and more treatment-related deaths, than their older counterparts. "You've got to consider both efficacy and toxicity in the picture," said Susan Ellenberg, who has studied drug side effects at the University of Pennsylvania's Perelman School of Medicine in Philadelphia.
She said the analysis wasn't so surprising, and isn't "a big alarm."
"People are willing to accept a certain amount of excess toxicity if they think it's going to increase the chance of having their cancer cured," Ellenberg, who wasn't involved in the new study, told Reuters Health. "But that's not always true - it really depends on what the toxicity is."
And the balance of drug benefits and side effects may be different for each individual patient, researchers said, making treatment decisions extra tough. Dr. Eitan Amir from Princess Margaret Hospital in Toronto and his colleagues consulted side effect information from new drug labels and clinical trials.
Those drugs included bevacizumab (marketed as Avastin), docetaxel (Taxotere) and sunitinib (Sutent). Studies had between 266 and 1,725 cancer patients each. The researchers found cancer patients who were randomly assigned to the newer drugs were 40 percent more likely to die from a side effect than those in comparison groups, who were typically treated with the current standard of care at the time or a drug-free placebo. Continued...