In a novel breakthrough study, researchers at Memorial Sloan-Kettering Cancer Center (MSKCC) have discovered that a "dose-dense" regimen of standard chemotherapy agents and the antibody trastuzumab (Herceptin), a drug shown to cause cardiac toxicity, can safely treat breast cancer patients.
In earlier studies, the researchers evaluated the cardiac effects of breast cancer treatments including trastuzumab and anthracyclines demonstrating an acceptable safety margin.
However, the new study, led by Chau Dang, MD, a medical oncologist on the Breast Cancer Medicine Service at MSKCC, has shown an even lower risk of cardiac toxicity when standard doses of these drugs are administered more frequently over time - a treatment plan called "dose-dense," which has previously been shown to be a more effective anti-cancer approach.
In this study, a dose-dense regimen of doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan or Neosar) followed by paclitaxel (Taxol) was used. It was discovered that following this course of therapy - when given every two weeks instead of three - results in safe results in combination with trastuzumab.
Trastuzumab is used to treat breast cancer in women whose tumours contain the protein receptor called HER2.
The results of this study indicate that only 1.4 percent (one patient) of the 70 early-stage breast cancer patients treated with this regimen faced congestive heart failure after 28 months of follow-up.
The researchers noted that this rate of cardiac toxicity is lower than the 4 percent threshold that is generally considered acceptable, but it was still lower than what was found in larger, previously published trials assessing traditionally scheduled treatment with the use of trastuzumab.
It was concluded that this dose-dense regimen combined with trastuzumab is a safe and effective way to treat women with early-stage HER2-positive breast cancer in the adjuvant setting and there is no need to give up the use of this regimen as trastuzumab is also being administered.
The study is published in the latest issue of the Journal of Clinical Oncology.