Newer Breast Cancer Drug May Protect Heart
By uncovering how one breast cancer drug protects the heart and another does not, researchers believe they may have opened up a new way to screen drugs for possible heart-related side effects and to develop new drugs.
The Duke researches compared the actions of two breast cancer drugs in experiments involving human cells and rats. The drugs in question were the older drug trastuzumab, whose trade name is Herceptin, and the newer drug lapatinib, whose trade name is Tykerb.
The results of the study appear early online in the journal Proceedings of the National Academy of Science.
The main side effect of trastuzumab is that it can damage heart muscle cells. Heart abnormalities have been detected in 2 to 7 percent of women taking the drug, and about one in ten women cannot take the drug because preexisting heart problems put them at greater risk for heart damage. To date, there appear to be fewer cardiac effects associated with lapatinib therapy.
Both drugs are prescribed to women whose cancerous breast cells have HER2 genes that are overactive. Approximately one in four women with breast cancer have this overactive gene, which is associated with increased cancer recurrence and worse outcomes. Lapatinib was approved earlier in March for use in women who have not responded to trastuzumab therapy.
"Trastuzumab revolutionized the treatment of HER2-positive breast cancers and represents an effective therapy for some women with one of the most aggressive forms of breast cancer," said Duke oncologist Neil Spector, M.D., first author of the paper.. "However, now we have two agents that go after the same target and both have an effect against the cancer, but one appears to have a greater potential