Blood marker tests are a vital test in an aggressive disease like breast cancer. This test is useful in pre, during and post treatment stages. These may be done initially before commencing the treatment for cancer to assess its movement and spread to other parts of the body. During the therapy this test will help determine the response of the body to the treatment. Post treatment to check on the recurrence of the cancer this test may be done.
This essentially identifies and reveals cancer activity through blood in the body. Cancer many at times secretes a protein which is like a marker for that cancer or even the circulating tumor cells in the blood can be marked .
For evaluating ovarian and breast cancer – CA 15.3 marker can be used, for breast cancer – TRU-QUANT & CA 27.29 marker are used. Similarly for liver, lung and colon cancers CEA is used. Circulating cancer celss denotes those tumor cells which are separated or broken from the original abnormal tissue growth and circulating in the body in blood. A “cellsearch test” has recently been approved for tracking these in metastatic cancer in women.
When the current therapy result is to be assessed this marker tests give definite results. In case a therapy is not working or the body is responding to a specific treatment with the help of this test it can be determined if the cancer is spreading or recurring and accordingly a treatment plan can be devised for best results. These tests just confirm the presence of tumor cells they are not conclusive on whether the cancer is gone or is spreading.