Breast cancer is a disease in which cells within the breast mutate and begin to proliferate uncontrollably. Breast cancer detection relies on regular breast examinations and mammograms, and breast cancer diagnosis relies on analysis of breast tissue to look for the presence of cancer. Advances in research have allowed for the development of several blood tests that can indicate the presence of breast cancer, as well as provide information about the properties of the tumor.
CEA
Carcinoembryonic antigen, or CEA, can be used as a marker for breast cancer in a blood test. This protein is produced by cancer cells or stem cells but not by normal cells. CEA blood testing generally is used to test later-stage forms of breast cancer, according to Imaginis.com. Cancer cells producing high levels of CEA are considered similar to stem cells, and they have a greater potential to give rise to tumors than cancer cells with low levels of CEA. Thus, the level of CEA in the blood is a prognostic indicator for breast cancer.
A positive CEA test alone is not sufficient to diagnose breast cancer, as many types of cancer produce the CEA protein. If a CEA blood test is positive, mammograms and biopsy testing of breast tissue should be performed to allow for diagnosis and staging of the breast cancer. CEA blood testing also can be used during cancer therapy to help gauge the effectiveness of the treatment and monitor the possibility of cancer recurrence.
CA 27.29
A CA 27.29 blood test can indicate the presence of breast cancer. CA 27.29 is a molecule called a glycoprotein, which is made up of a protein bound to carbohydrate chains. It is found on the surface of cancer cells, so testing for the presence of CA-27.29 in the blood indicates the presence of breast cancer cells in the blood.
CA 27.29 blood testing can be used to indicate the aggressiveness of a breast tumor, according to a study published in Journal of Clinical Oncology in 2009. Dr. V. Ghai found that increased levels of CA 27.29 in the blood correlated with more advanced forms of breast cancer. The study also indicates that CA 27.29 blood testing allows doctors to track the efficacy of treatment to provide reassurance to patients that their cancer is regressing.
DNA Fingerprinting
An advanced blood testing procedure, known as DNA fingerprinting, also may be used as a biomarker for breast cancer in a blood test. The DNA fingerprinting test is based on the principle that normal cells around the tumor site become damaged, leaking their DNA into the bloodstream as the normal cell is destroyed and dies. The leaked DNA then is detected in the blood, indicating the presence of cancer. Analysis of blood from a patient also will allow doctors to gain information about the characteristics of the tumor.
Reuters reports that the DNA fingerprinting test will allow doctors to investigate the genetic profile of patients to determine which therapies to use in breast cancer treatment. Although the test is in the development stage, the DNA fingerprint test was able to correctly detect breast cancer in 70 percent of patients tested and correctly indicated an absence of breast cancer in 100 percent of test subjects.
