Tumor Markers

Tumor markers are measurable proteins, genes, mutations, cell characteristics, and other biological signals that can provide important information about cancer risk, diagnosis, tumor type, prognosis, treatment options, and disease monitoring. This category offers clear, comprehensive guides to the many different tests used across modern oncology and pathology. Explore common blood tumor markers such as PSA, AFP, CEA, CA-125, CA 19-9, and beta-2 microglobulin; urine biomarkers for prostate, bladder, kidney, and neuroendocrine tumors; and tissue-based immunohistochemistry (IHC) markers used to identify tumor origin and cancer subtype. Coverage also includes cancer gene mutations and fusions such as BRCA1/2, EGFR, KRAS, BRAF, ALK, NTRK, BCR-ABL1, and TP53, as well as liquid biopsy, circulating tumor DNA (ctDNA), circulating tumor cells, and minimal residual disease testing. You can also explore biomarker testing for breast, prostate, ovarian and gynecologic, gastrointestinal, pancreatic, liver, lung, and hematologic cancers, including leukemia, lymphoma, and multiple myeloma. Each guide explains what a marker measures, why the test may be ordered, what positive, negative, high, low, or abnormal results can mean, and important limitations. The goal is to make complex tumor-marker testing easier to understand while showing how individual results fit into the broader clinical picture.