"Dose-dense" chemo cuts Herceptin heart risk-study

LOS ANGELES, March 6 (Reuters) - Combining targeted breast cancer treatment Herceptin with a more frequent chemotherapy regimen reduces the risk of heart problems related to the Genentech drug, according to researchers at New York's Memorial Sloan-Kettering Cancer Center.

Previous studies have shown that when standard chemotherapy drugs are administered every two weeks -- a treatment plan called "dose-dense" -- the likelihood of survival is improved and the risk of cancer recurrence is lowered.

But some oncologists have hesitated to use Genentech Inc's (DNA.N: Quote, Profile, Research) Herceptin in conjunction with more frequent chemotherapy for fear of heart damage, said Dr. Chau Dang, an oncologist at Sloan-Kettering and the study's lead researcher.

"We are excited about this because we saw that the risk of cardiac toxicity is actually lower," she said.

Herceptin, or trastuzumab, is an antibody-based drug used to treat the 25 percent to 30 percent of breast cancer patients who have tumors that generate a protein called HER-2.

These tumors tend to grow faster and are more likely to recur than tumors that do not carry the protein.

Unlike chemotherapy, which is toxic throughout the body, Herceptin is designed to target tumor cells and spare normal cells, but it still causes side effects, the most serious being congestive heart failure, which occurs in up to 4 percent of patients treated with the injected drug.

The small Sloan-Kettering study demonstrated an even lower risk of cardiac toxicity when standard chemotherapy drugs are administered once every two weeks, instead of once every three weeks, which is the regimen under which previously-published trials evaluated Herceptin.

The study of 70 patients with early-stage breast cancer found that just one patient, or 1.4 percent, experienced congestive heart failure after 28 months of follow-up.