Herceptin Side Effects May Increase Heart Disease In Older Women: Study

New research has linked side effects of Herceptin, a popular breast cancer treatment drug, to higher incidents of heart problems among older women. 

In a study published in the Journal of Clinical Oncology on October 14, researchers indicate that Herceptin was associated with a higher risk of heart problems, including congestive heart failure (CHF) in women. It is not the first time the Roche cancer drug has been linked to heart problems.

Researchers from the Anderson Cancer Center at the University of Texas studied data on nearly 10,000 women over 66 years old who have been diagnosed with stage I to III breast cancer, from 2005 to 2009.

The patients were treated with chemotherapy and identified using the Surveillance, Epidemiology, and End Results (SEER) Medicare and Texas Cancer Registry-Medicare Database. Researchers identified 2,203 patients who received Herceptin in conjunction with chemotherapy during breast cancer treatment.

The study indicates that the rate of heart problems for those being treated for cancer who took Herceptin was nearly 30% higher than women who did not have breast cancer. Breast cancer patients who did not take Herceptin had only a 19% increased risk of congestive heart failure.

The researchers found that age and previous heart problems also played a factor. Patients who were older were more likely to develop CHF, with patients 80 years old or older being 53% more likely to develop congestive heart failure than patients between the ages of 66 to 79. The average age of participants in the study was 71 years of age.

Patients who already had heart problems had an 82% increased risk of developing further problems, such as congestive heart failure, after using Herceptin. Patients with hypertension were also 24% more likely to develop CHF.

Overall Herceptin users were 95% more likely than non-herceptin users to develop congestive heart failure. Taking Herceptin weekly, as opposed to every three weeks, increased the risk by 33%.

Researchers found the risk of developing heart disease after Herceptin use was higher during the study than during the initial clinical trials.

Other Herceptin Heart Problem Studies

The Roche cancer drug attracted media attention after a study last year suggested Herceptin side effects may incease the risk of developing heart failure or cardiomyopathy. The risk of heart failure among patients taking Herceptin was 1.4 times higher than in women treated with anthracycline, another anticancer drug used in conjunction with chemotherapy, during breast cancer treatments.

A study published in the Annals of Oncology in 2011 also had similar findings to this most recent research, suggesting that older patients with a history of cardiac disease or diabetes were at higher risk of developing asymptomatic cardiotoxicity and symptomatic congestive heart failure from Herceptin.

Herceptin (trastuzumab), is a drug that targets the human epidermal growth factor receptor (HER2) protein. It is used to help treat breast cancer patients and increase their life expectancy.

Breast cancer is one of the most common cancers found in the U.S. with more than 232,000 new diagnoses reported in 2011 alone. Herceptin is the leading treatment for HER2 breast cancer and is often used in combination with other anticancer chemotherapy drugs.