According to updated results from the Herceptin Adjuvant (HERA) study, one year of Herceptin® (trastuzumab) following chemotherapy results in better overall survival than chemotherapy alone in women with HER2-positive early breast cancer. These results were published in the Lancet.
Approximately 30% of breast cancers overexpress a protein known as the human epidermal growth factor receptor-2 (HER2). The HER2 protein is involved in cellular growth and replication. Women with HER2-positive breast cancer tend to have a worse prognosis than women with HER2-negative breast cancer. Fortunately, the targeted agent Herceptin binds to HER2 receptors and prevents or reduces replication of cancer cells that overexpress HER2.
The HERA study is a Phase III clinical trial that randomly assigned HER2-positive early breast cancer patients to one of three treatment groups following chemotherapy: observation, one year of Herceptin, or two years of Herceptin. All study participants had node-positive or high-risk node-negative breast cancer.
The current analysis focuses on the 1,703 women randomly assigned to one year of Herceptin and the 1,698 women in the observation group. Previously reported results from this study indicated that one year of Herceptin improved cancer-free survival. The current results provide information about overall survival after two years of follow-up.
- Overall survival was 92.4% among women in the Herceptin group and 89.7% among women in the observation group.
- Cancer-free survival was 80.6% among women in the Herceptin group and 74.3% among women in the observation group.
- Women in the Herceptin group were more likely than women in the observation group to develop heart problems. 4.3% of women treated with Herceptin discontinued use because of the development of heart problems.
The researchers conclude that one year of Herceptin after chemotherapy improves survival among women with HER2-positive early breast cancer. The researchers note that “The emergence of this benefit after only 2 years reinforces the importance of [Herceptin] in the treatment of women with HER2-positive early breast cancer.”
Reference: Smith, I, Proctor M, Gelber RD et al. 2-year Follow-up of Trastuzumab after Adjuvant Chemotherapy in HER2-positive Breast Cancer: A Randomised Controlled Trial. Lancet. 2007;369:29-36.