According to results recently presented at the 2007 annual San Antonio Breast Cancer Symposium, treatment with Herceptin® (trastuzumab) after cancer has spread to the brain improves survival for breast cancer patients.
Metastatic breast cancer refers to cancer that has spread from the breast to distant sites in the body. Specifically, cancer that has spread to the brain is known as brain metastasis.
Approximately 25% of breast cancers are epidermal growth factor receptor 2 (HER2)-positive, meaning that they overexpress HER2, which is involved in cellular growth and replication. Herceptin targets HER2 and reduces growth and spread of HER2-positive breast cancer. Clinical trials are still being conducted to determine the optimal approach to treatment including chemotherapy plus Herceptin for this disease.
A concern regarding Herceptin is that it does not cross the blood–brain barrier, a membrane that surrounds the brain and spinal column. Therefore, Herceptin is not able to kill cancer cells that have spread to these areas. It is not known, however, whether treatment with Herceptin following onset of brain metastasis will improve survival in these patients.
Researchers recently conducted a clinical study to evaluate data from 56 patients with HER2-positive metastatic breast cancer with brain metastasis. Patients received treatment for their brain metastasis and had also received treatment either with Herceptin alone, Herceptin plus chemotherapy, or treatment that did not contain Herceptin. Associations were evaluated between patient outcomes and treatments prior to brain metastasis and following the development of brain metastasis.
- Overall survival was significantly improved among patients who received treatment with Herceptin after the development of brain metastasis compared with those who received Herceptin before the development of brain metastases or did not receive Herceptin.
- In a subgroup analysis, patients with hormone receptor-negative breast cancers demonstrated improved survival if they had been treated with Herceptin after the development of brain metastasis compared with treatment before the development of brain metastasis.
- There was no difference in survival among patients with hormone receptor-positive breast cancers in regards to the timing of treatment with Herceptin
- The time interval from the diagnosis of metastatic or recurrent breast cancer to the development of brain metastasis was also associated with survival: longer time intervals were associated with longer survival time).
The researchers concluded that it appears that treatment with Herceptin following the development of brain metastasis significantly improves overall survival among patients with advanced HER2-positive breast cancer. Further study regarding the timing of Herceptin among patients with brain metastasis is warranted.
Patients with advanced HER2-positive breast cancer may wish to speak with their physician regarding their individual risks and benefits of participating in a clinical trial further evaluating Herceptin in different treatment regimens or other promising therapeutic approaches. Two sources of information regarding ongoing clinical trials are the National Cancer Institute (http://www.cancer.gov) and http://www.eCancerTrials.com.
Reference: Nam B, Kim S, Han H, Lee K, Ro J. Survival Gain by trastuzumab therapy after the onset of intracranial metastasis in metastatic breast cancer. Proceedings from the 30th Annual San Antonio Breast Cancer Symposium; December 13-16, 2007; San Antonio, Texas. Abstract 4061.
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