An elevated tumor marker result can be concerning, but it does not automatically indicate cancer. Tumor markers are substances found in the body whose levels may be higher than normal due to various conditions, both cancerous and non-cancerous.
What Are Tumor Markers?
Tumor markers are specific molecules produced by cancer cells or by the body in response to the presence of cancer. These substances can include proteins, enzymes, or hormones. They are detectable in various bodily fluids, such as blood, urine, or other tissues.
The measurement of tumor markers typically involves a blood test, but can also be done through urine, stool, or tissue samples. An “elevated” result means the concentration of a particular marker in the body is higher than the established normal range for that marker.
Common examples of tumor markers include Prostate-Specific Antigen (PSA), which is associated with prostate cancer, and Cancer Antigen 125 (CA-125), often linked to ovarian cancer. Carcinoembryonic Antigen (CEA) is another marker that can be elevated in several gastrointestinal cancers, including colorectal, pancreatic, stomach, and liver cancers.
Why Tumor Markers Can Be Elevated
Elevated tumor marker levels are not exclusively indicative of cancer. Many non-cancerous conditions can also cause these markers to rise, leading to what is known as a false positive. For instance, inflammatory conditions, chronic infections, or autoimmune diseases can cause an increase in certain tumor markers.
Benign tumors, which are non-cancerous growths, can also lead to elevated tumor marker levels. Conditions affecting organs like the liver or kidneys, such as hepatitis or kidney disease, may impact the body’s ability to clear these markers, resulting in higher concentrations in the bloodstream. Even lifestyle factors like smoking can elevate specific markers, such as carcinoembryonic antigen (CEA).
However, various types of cancer can also cause elevated tumor markers. For example, PSA levels often rise with prostate cancer, while CA-125 can be elevated in ovarian cancer. CEA is frequently associated with colorectal cancer and can also be seen in lung, breast, and pancreatic cancers. An elevated marker suggests the need for further investigation to determine the underlying cause, whether it is cancerous or not.
Navigating an Elevated Result
Tumor marker tests are generally not used for broad cancer screening in people without symptoms due to their limitations. This is because these tests can produce false positives, where the marker is elevated but no cancer is present, or false negatives, where cancer exists but the marker levels are normal.
The sensitivity of these tests, which measures their ability to detect cancer when it is present, can be low for early-stage cancers. Similarly, their specificity, which indicates their ability to show a negative result when cancer is absent, is also not perfect. For example, CA-125, while associated with ovarian cancer, can also be elevated in common benign conditions like endometriosis, fibroids, or even pregnancy.
Healthcare providers typically use tumor markers in conjunction with other diagnostic tools, such as imaging scans (MRI, CT scans, ultrasound) and biopsies. Their primary utility lies in monitoring known cancers to assess treatment effectiveness or to detect recurrence after treatment. Therefore, an elevated marker serves as a sign that warrants further comprehensive medical evaluation, not a standalone diagnosis.
Next Steps After an Elevated Result
When an elevated tumor marker result is found, a healthcare provider should be consulted. The doctor will consider the specific marker, its elevation, and your medical history and symptoms. Further diagnostic tests are commonly ordered.
These may include additional blood tests to assess other health indicators, advanced imaging studies like MRI, CT scans, or PET scans to visualize internal organs and identify any abnormalities, or biopsies, which involve taking a tissue sample for microscopic examination. These comprehensive tests help to confirm or rule out a cancer diagnosis or identify other non-cancerous conditions.
You may also be referred to a specialist, such as an oncologist or a gastroenterologist, depending on the specific tumor marker and suspected underlying condition. Open communication with your healthcare team is important to understand the results and the rationale behind the recommended next steps. Repeated testing of tumor markers over time can also be performed to observe trends, which offers more insight than a single measurement.