Cancer Tumor Markers

What Are They?

Cancer Tumor Markers are substances (usually proteins) that are found in blood that can help identify cancer. Many times this substance is elevated in cancer types and this is called a cancer specific tumor marker. Your doctor may take a blood sample to look for a tumor marker, however Cancer specific markers are not generally used as a way to screen for cancer because they are not specific or sensitive enough to make a diagnoses or determination.

How Are They Used?

Many physicians will use the cancer specific tumor marker to help them follow your disease. The tumor marker might indicate how well you are responding to treatment and following treatment it might indicate whether your cancer has returned. The cancer specific marker can help them identify how quickly the disease is changing for better or worse.

CEA

Carcinoembryonic antigen or CEA is one type of cancer-specific marker that found by tumors that arise in the gastrointestinal system. An elevated CEA does not imply that you have a GI cancer, because it can be shown to be elevated in people without GI disease. Rather, a CEA is monitored because if you have GI cancer and an elevated CEA it might indicate your cancer is growing. The physician may ask you to undergo another scan to see if you cancer has progressed or recurred.

PSA

Prostate Specific Antigen or PSA is a protein that only men can develop that is specific to the prostate organ. A blood test can be used to determine a man's PSA. There is a correlation between the rise of PSA and the development of metastatic prostate cancer. PSA is used as a marker for following prostate cancer patients.

CA 125

Cancer Antigen or CA-125 is a protein that both men and women have and is used as a cancer specific tumor marker in ovarian and GI cancers. Scientists and doctors are measuring women's level of CA 125 to determine if a woman is at an increased risk for ovarian cancer. CA 125 is used to check to see if cancer has returned.

Are They Used to Diagnose?

Tumor markers are not definitive for making diagnosis of cancer. They are one method of helping to monitor your cancer treatment, determine recurrence, and determine treatment options. Treatment options may include drugs such as chemotherapy or monoclonal antibodies. Bio-pharmaceutical companies are developing hundreds of monoclonal antibodies that are made to target specific cells in the body. Click on the link below to read more about monoclonal antibodies.

For More Information Ask Your Doctor About Tumor Markers.

Your doctor will undergo complete staging in order to diagnose your cancer. Staging may include a biopsy, resection, a clinical workup and additional blood tests, such as testing for tumor markers.