Alpha-fetoprotein (AFP) is a protein primarily produced by the liver of a developing fetus. In adults, it is measured to help diagnose liver diseases, such as cirrhosis or liver cancer, and to monitor fetal development during pregnancy. Elevated AFP levels in adults can indicate liver issues, while abnormal AFP levels during pregnancy may suggest potential birth defects, such as neural tube defects. This test is valuable for assessing liver health and monitoring fetal well-being.

Beta-2 Microglobulin (B2M) is a protein present on the surface of many cells, particularly immune cells, and is released into the blood when cells are broken down. It is commonly used as a marker for kidney function, with elevated levels indicating potential kidney dysfunction. High B2M levels may also be seen in conditions such as multiple myeloma, lymphomas, and chronic inflammatory diseases, helping to assess disease severity and monitor treatment progress.

The CA 125 test measures the level of a protein in the blood that can be elevated in ovarian cancer and other conditions. It is used to monitor ovarian cancer, evaluate treatment effectiveness, and detect recurrence. Since elevated CA 125 levels can also occur in non-cancerous conditions, the test is typically combined with other diagnostic tools for accurate results.

CA 15-3 is a blood test used to measure the level of cancer antigen 15-3, a protein often elevated in women with breast cancer. It is primarily used to monitor treatment response and detect recurrence in patients already diagnosed with breast cancer. However, elevated levels can also be found in other cancers or benign conditions. Therefore, the test is typically combined with other diagnostic methods to provide a more accurate assessment.

The CA 19-9 test measures the level of a protein that can be higher in certain cancers, especially pancreatic cancer, as well as in colorectal or stomach cancer. It may also be elevated in non-cancerous conditions like liver disease or pancreatitis. This test is useful for monitoring treatment, checking for cancer recurrence, and helping diagnose cancer when used with other tests.

CA 50 is a blood test used to measure the level of cancer antigen 50, a protein found on the surface of certain cancer cells. It is primarily used as a tumor marker for pancreatic cancer but may also be elevated in other cancers, such as colorectal, ovarian, and gastric cancers. Elevated CA 50 levels can indicate cancer or non-cancerous conditions like liver disease or pancreatitis. This test is commonly used to monitor known cancer patients, assess treatment effectiveness, or check for recurrence, but it is not specific enough to be used as a primary screening test for cancer.

CA 72-4 is a tumor marker used to measure the level of cancer antigen 72-4, a protein often elevated in specific cancers, particularly gastric cancer. It is utilized to monitor treatment response and detect recurrence in patients with known gastric cancer. Elevated CA 72-4 levels may also be seen in cancers such as ovarian, colorectal, and pancreatic cancers, as well as in non-cancerous conditions like liver disease and inflammation. However, it is not typically used alone for diagnosing cancer due to its lack of specificity.

Carcinoembryonic Antigen (CEA) is a protein typically found in low levels in healthy adults, but its levels can be elevated in the blood due to certain cancers and some non-cancerous conditions. It is commonly used as a tumor marker, especially for colon and rectal cancers, and may also be elevated in cancers of the lung, breast, pancreas, stomach, and thyroid.

Human Epididymis Protein 4 (HE4) is a protein found in various tissues, including the reproductive and respiratory tracts, with elevated levels often detected in cases of ovarian cancer. HE4 is commonly used as a biomarker, in combination with other tests, to aid in the detection of ovarian cancer, monitor treatment response, and assess the likelihood of cancer recurrence.

Neuron-specific enolase (NSE) is a protein found primarily in neurons and neuroendocrine cells, involved in energy production within cells. Elevated levels of NSE in the blood are associated with nerve tissue damage or certain cancers, particularly those originating in neuroendocrine cells, such as small cell lung cancer or neuroblastoma. This test is used to help diagnose and monitor conditions affecting the nervous system and detect related tumors.

The Risk of Ovarian Malignancy Algorithm (ROMA) is used to evaluate the likelihood of ovarian cancer in women with a pelvic mass. By analyzing biomarker levels (HE4 and CA-125) along with menopausal status, a more accurate risk score is provided. The ROMA test is important for assessing the risk of ovarian cancer and aiding in decision-making for further diagnostic procedures.

Squamous Cell Carcinoma Antigen (SCCA) is a protein often elevated in the blood of individuals with squamous cell carcinoma (SCC). It is used as a tumor marker for diagnosing and monitoring SCC, particularly in lung, head and neck, and cervical cancers. High levels of SCCA may indicate the presence or recurrence of SCC, although it can also be elevated in other conditions like inflammation.