Breast Cancer Drug Connected To Higher Risk Of Heart Problems

A study conducted at the Avera Cancer Institute in Sioux Falls has concluded that the breast cancer drug Herceptin (trastuzumab) is linked to higher risks of heart problems. Although the risk of heart problems is real, the researchers also found that the issues usually reverse once Herceptin treatment is completed. The study was funded by Roche, the drug company that produces Herceptin. Roche also included company researchers and consultants as study co-authors. Dr. Brian Leyland-Jones, the vice president of molecular and experimental medicine at the Avera Cancer Institute, said that the overall result of the study was one of “tremendous reassurance.” The study was published online in the June edition of the Journal of Clinical Oncology.

Heart problems linked with Herceptin include congestive heart failure and a decrease in the capacity to pump blood out of the left ventricle. The study looked at 5,000 women with early stage breast cancer, followed for an average of 8 years. The women were split into three groups of 1,700 patients, with one group taking Herceptin for 1 year, the second for 2 years, and the third on placebo. Nearly 10 percent of women in the 2 year group and 5 percent in the 1 year group had to stop taking the drug because of heart issues.

The researchers noted that the link between Herceptin and heart problems was not large, and that the drug treatment was important. “What this confirms is a very low incidence of cardiac events, even when you give two years of the drug, which is no longer practiced," Leyland-Jones said.

Herceptin is used to treat patients with breast cancer that test positive for the HER 2 receptor. This receptor encourages the growth of cancer cells. Herceptin kills those cells, which boosts survival rates. Herceptin is usually used to treat patients after surgery, chemotherapy, and radiation have failed to produce satisfactory results.