Evidence-Based Supplement & Herb Guides

4Kscore Test: PSA Markers, Prostate Cancer Risk Score, and Result Meaning

Learn how the 4Kscore combines four PSA-related kallikrein markers with clinical factors to estimate significant prostate cancer risk and guide MRI or biopsy decisions.

The 4Kscore test is a blood test used after prostate cancer risk has already become a concern, often because prostate-specific antigen (PSA) is elevated...

5-HIAA Blood Test: Carcinoid Syndrome, Serotonin Metabolism, Neuroendocrine Tumors, and Meaning

Understand what a 5-HIAA blood test measures, what high levels can mean in carcinoid syndrome and neuroendocrine tumors, and how blood results compare with 24-hour urine testing.

A 5-HIAA blood test measures 5-hydroxyindoleacetic acid, the main breakdown product of serotonin. It is used mainly when a serotonin-producing neuroendocrine tumor is suspected...

Alpha-Fetoprotein (AFP) Blood Test: High Levels, Liver Disease, Liver Cancer, and Germ Cell Tumors

Learn what an AFP blood test measures, why AFP rises in liver disease, hepatocellular carcinoma, and germ cell tumors, and how normal ranges and trends guide follow-up.

Alpha-fetoprotein, or AFP, is a protein made in large amounts by the fetal liver and yolk sac but normally present only at low levels...

Anti-Mullerian Hormone (AMH) Tumor Marker Test: Granulosa Cell Tumors, Tumor Activity, and Follow-Up

Learn how AMH is used as a tumor marker for granulosa cell tumors, why levels can rise, how trends are followed after treatment, and how AMH compares with inhibin B.

Anti-Müllerian hormone, or AMH, is best known as a blood marker of ovarian reserve, but it also has an important tumor-marker role in ovarian...

Beta-2 Microglobulin Blood Test: Myeloma, Lymphoma, Leukemia, Kidney Function, and Prognosis

Learn how beta-2 microglobulin is used in myeloma, lymphoma, and leukemia, why kidney function raises B2M, and how staging thresholds and trends are interpreted.

Beta-2 microglobulin, usually shortened to beta-2 microglobulin or B2M, is a small protein released from the surface of most nucleated cells. A blood B2M...

Beta-hCG Tumor Marker Test: Testicular Cancer, Ovarian Germ Cell Tumors, and High Levels

Learn how beta-hCG is used in testicular and ovarian germ cell tumors, what high levels can mean, and why pregnancy, false positives, and marker trends matter.

Beta-human chorionic gonadotropin, or beta-hCG, is best known as a pregnancy hormone, but it is also an important blood tumor marker in germ cell...

Blood Tumor Marker Test Panel: AFP, CEA, CA-125, CA 19-9, PSA, and What They Measure

Understand what AFP, CEA, CA-125, CA 19-9, and PSA blood tumor markers measure, their common reference limits, cancer uses, benign causes, and key limitations.

A blood tumor marker panel can include tests such as alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125), cancer antigen 19-9 (CA 19-9),...

Calcitonin Blood Test: Medullary Thyroid Cancer Marker, High Levels, and C-Cell Disease

Learn how the calcitonin blood test is used for medullary thyroid cancer and C-cell disease, what high levels mean, benign causes, and how results guide follow-up.

Calcitonin is a hormone made mainly by the thyroid's parafollicular C cells. A blood calcitonin test is most important as a tumor marker for...

Cancer Antigen 15-3 (CA 15-3) Blood Test: Breast Cancer Monitoring, Recurrence, and Tumor Marker Meaning

Learn what the CA 15-3 blood test measures, common reference ranges, its role in metastatic breast cancer monitoring, recurrence limits, and benign causes of high results.

Cancer antigen 15-3, or CA 15-3, is a blood tumor marker that measures a circulating form of the MUC1 protein. Many breast cancers release...

Cancer Antigen 19-9 (CA 19-9) Blood Test: High Levels, Pancreatic Cancer, Bile Duct Disease, and Meaning

Learn what high CA 19-9 means, how pancreatic and bile duct cancers use this marker, why jaundice causes false elevations, and how Lewis status affects results.

Cancer antigen 19-9, or CA 19-9, is a blood tumor marker used mainly in pancreatic and biliary tract cancers. It can help estimate disease...

Cancer Antigen 27.29 (CA 27.29) Blood Test: Breast Cancer Monitoring, Recurrence, and Result Meaning

Learn what the CA 27.29 blood test measures, its common reference range, how it is used in breast cancer monitoring, recurrence limits, and reasons for high results.

Cancer antigen 27.29, or CA 27.29, is a blood tumor marker that measures a circulating portion of MUC1, a protein commonly overexpressed and abnormally...

Cancer Antigen 125 (CA-125) Blood Test: High Levels, Ovarian Cancer Monitoring, and Non-Cancer Causes

Understand CA-125 blood test results, including normal ranges, high levels, benign causes, ovarian cancer monitoring, recurrence trends, and follow-up.

Cancer antigen 125, usually called CA-125, is a protein measured in blood that is most useful for following certain ovarian, fallopian tube, and primary...

Carcinoembryonic Antigen (CEA) Blood Test: High Levels, Colon Cancer Monitoring, and Benign Causes

Learn what a CEA blood test measures, typical reference ranges, benign causes of high CEA, and how serial CEA levels help monitor colorectal cancer and recurrence.

Carcinoembryonic antigen, or CEA, is a blood tumor marker used mainly to monitor colorectal cancer and several other cancers after diagnosis. It is not...

Chromogranin A Blood Test: Neuroendocrine Tumors, High Levels, Medication Effects, and Monitoring

Learn how the chromogranin A blood test is used for neuroendocrine tumors, why PPIs and benign conditions raise CgA, and how serial results are interpreted.

Chromogranin A (CgA) is a protein stored and released by neuroendocrine cells, so a blood test for CgA can be useful in selected people...

Circulating Tumor Cell (CTC) Blood Test: Cancer Monitoring, Tumor Cells in Blood, and Prognosis

Learn how circulating tumor cell blood tests detect tumor cells, what CTC counts mean, how they relate to prognosis and monitoring, and how CTCs differ from ctDNA.

A circulating tumor cell (CTC) blood test looks for intact cancer cells that have detached from a tumor and entered the bloodstream. These cells...

Complexed PSA Test: High Levels, Prostate Cancer Risk, and PSA Result Meaning

Learn what complexed PSA measures, what high cPSA may mean, how it differs from total and free PSA, and how modern prostate-cancer risk assessment uses PSA results.

Complexed prostate-specific antigen (complexed PSA or cPSA) measures the portion of PSA in blood that is bound to certain proteins, especially alpha-1-antichymotrypsin. Most measurable...

CYFRA 21-1 Blood Test: Lung Cancer Marker, High Levels, and Disease Monitoring

Learn what CYFRA 21-1 measures, typical reference limits, causes of high levels, and how this lung cancer marker may help with NSCLC prognosis and monitoring.

CYFRA 21-1 is a blood tumor marker that measures soluble fragments of cytokeratin 19, a structural protein found in many epithelial cells. It is...

Des-Gamma-Carboxy Prothrombin (DCP) Test: Liver Cancer Marker, High Levels, and HCC Risk

Learn what the DCP/PIVKA-II blood test measures, why levels rise, how vitamin K affects results, and how DCP supports HCC risk assessment and treatment monitoring.

Des-gamma-carboxy prothrombin (DCP) is an abnormal form of prothrombin measured in blood as a tumor marker for hepatocellular carcinoma (HCC), the most common primary...

Free PSA Test: Percent Free PSA, Prostate Cancer Risk, and PSA Interpretation

Learn how the free PSA test and percent free PSA help refine prostate cancer risk, what common percentage ranges mean, what affects results, and when follow-up is needed.

A free PSA test measures the amount of prostate-specific antigen (PSA) circulating in the blood without being attached to other proteins. It is usually...

Gastrin Blood Test: Gastrinoma, Zollinger-Ellison Syndrome, High Levels, and Stomach Acid

Understand what a gastrin blood test measures, why gastrin can be high, how gastrinoma and Zollinger-Ellison syndrome are diagnosed, and how PPIs affect results.

A gastrin blood test measures gastrin, a hormone that signals the stomach to make acid. It is most often ordered when a clinician suspects...