A new blood test may help improve the detection of residual breast cancer cells in the body following treatment, according to researchers at the St. Johns Health Center in California. Through improved detection, additional treatment may be administered earlier, when only microscopic amounts of cancer exist. This would enable breast cancer patients to achieve the highest potential of experiencing a cure.
Breast cancer is a common malignancy occurring in women in the United States, with almost 200,000 new cases diagnosed each year. Depending on the extent of the cancer, treatment options may include surgery, chemotherapy, radiation therapy, hormone therapy and/or stem cell transplantation. However, often times following treatment, microscopic amounts of cancer cells remain in the body (micrometastases) which are responsible for cancer recurrences. In order to ensure optimal chances of a cure, patients with micrometastases should be treated with additional therapy to destroy the remaining cancer cells.
At present, current breast cancer screening and detection methods are only sensitive enough to detect cancers of sufficient size or extent, and are often unable to detect micrometastases. This fact alone hinders the potential of achieving a cure for many breast cancer patients since treatment is delayed until their cancer can be detected. This has resulted in extensive research efforts to improve the sensitivity of detection methods, including the use of blood tests, so treatment can begin as early as possible when it is the most effective.
A novel blood test has recently been developed with the hope of detecting micrometastases following treatment in breast cancer patients. The test is designed to identify small amounts of cancer cells circulating in the patient’s blood by recognizing a specific protein that is found on the surface of breast cancer cells, called TA-90.
In one study evaluating the new TA-90 blood test, over 200 women were examined to determine whether there was a direct correlation between levels of TA-90 in the blood and the presence of breast cancer. Over 60% of women who had breast cancer exhibited high levels of TA-90 in their blood. Conversely, almost 98% of women who did not have breast cancer did not have elevated TA-90 blood levels.
Another study evaluating the accuracy of TA-90 blood levels involved almost 130 women who were known to have breast cancer. Each patient had TA-90 blood levels measured
after the surgical removal of their cancer. Almost 80% of women who had high TA-90 levels following surgery experienced a recurrence of cancer. Importantly, all of these women had been determined to be “disease-free” through conventional detection methods. In addition, approximately 80% of women who did not have high TA-90 levels following surgery, did not experience a cancer recurrence.
These results are encouraging as they indicate a clear association between elevated blood TA-90 levels and the existence of cancer in the body. The immediate implications of this test are for the detection of residual cancer following local treatment with surgery, radiation and/or chemotherapy. In the future, this blood test may be used in combination with other screening procedures to improve the accuracy of early detection of breast cancer.
Patients with breast cancer or who are at a high-risk for developing breast cancer may wish to speak with their physician about the risks and benefits of participating in a clinical trial further evaluating TA-90 blood levels or other promising detection methods.