A new blood test shows promise in helping physicians better manage the treatment of women with Simple Blood Test May Indicate Whether Breast Cancer Treatment is Working (dateline October 29, 2007) | Breast Health News | Imaginis - The Women's Health & Wellness Resource Network

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Simple Blood Test May Indicate Whether Breast Cancer Treatment is Working

 A new blood test shows promise in helping physicians better manage the treatment of women with advanced breast cancer. The CellSearchTM test measures the number of Circulating Tumor Cells (CTCs) in a sample of blood and can immediately inform physicians if a patient's treatment is working or needs modification. Such information can be crucial for treating women with metastatic breast cancer, an advanced form of breast cancer that has potential to spread to other body organs.

The CellSearch test was approved by the U.S. Food and Drug Administration (FDA) in January 2004 and given further clearance in December 2006 as a routine monitoring test in women with advanced breast cancer. Recent studies presented at national symposia such as the American Society of Clinical Oncology (ASCO) suggest that the CTC test can help predict survival and manage treatment. While the test is used independently-typically following each chemotherapy treatment cycle-health experts do not recommend that it replace existing tests to monitor disease progression, such as the CAT scan or PET scan. Instead, it can be a useful supplement to those tests, which are often administrated every 12 to 24 weeks.

Developed by Immunicon Corporation (www.immunicon.com), and marketed by Veridex LLC (www.veridex.com), a Johnson & Johnson Company, the CellSearch CTC test is increasingly available at pathology laboratories in the United States. The blood test costs around $500. According to Immunicon, Medicare and most private insurers cover the test.

Circulating tumor cells are shed by tumors and enter the bloodstream, where they can spread to other body organs in patients with advanced cancers. The CTC test works by analyzing the cells in a patient's blood sample to count and characterize them. Studies published in Clinical Cancer Research, the Journal of Clinical Oncology and the New England Journal of Medicine suggest that the CTC test can predict survival in patients with advanced breast cancer.

According to Immunicon, if a patient typically has more than five CTCs in a blood sample, survival may be shorter compared to patients with no CTCs. The CTC test can help physicians monitor a patient's treatment by determining whether the number of cancer cells is decreasing. This information can help determine whether changes are needed in a patient's treatment.

Such information is important, particularly for women with advanced breast cancer. About 25% of women with advanced, metastatic breast cancer survive longer than five years. The most common region breast cancer spreads to is the bone, followed by the lung and liver. Treatment will differ depending on the patient's history of treatment and how well she responds to specific therapies. Chemotherapy or other drug therapies are usually given to advanced breast cancer patients because they affect the entire body (as opposed to localized treatments that only affect one area).

In addition to breast cancer, researchers are investigating whether the CTC test can be useful in patients with advanced colon cancer or prostate cancer. Clinical data for those cancers are expected within the next two years.

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