Tumor Marker Tests
Tumor markers are specific substances (antigens, proteins, enzymes, hormones) produced by the body in response to malignant tumor development. Their detection in blood, urine, or other biological fluids helps diagnose cancer, monitor treatment effectiveness, and predict disease progression.
Types of tumor markers
- General tumor markers — indicate the presence of a tumor without specifying its location.
- Specific tumor markers — associated with particular cancer types (e.g., PSA for prostate cancer).
- Conditionally specific tumor markers — may be elevated in several tumor types or non-cancerous diseases (e.g., CA-125).
Main tumor markers for different organs
- Breast: CA 15-3, CEA, HER2 — used for diagnosis and monitoring of breast cancer.
- Liver: Alpha-fetoprotein (AFP) — marker of hepatocellular carcinoma.
- Uterus and ovaries: CA-125, HE4, SCC, β-hCG — used for diagnosis and monitoring of endometrial and ovarian cancers.
- Gastrointestinal tract: CA 19-9 (pancreatic and bile duct cancer), CEA (colon cancer), CA 72-4 (stomach cancer).
- Lungs: CYFRA 21-1 and NSE — markers of non-small cell and small cell lung cancers.
- Thyroid: Thyroglobulin — used in thyroid cancer diagnosis.
Indications for testing
- Suspicion of malignant neoplasm.
- Monitoring treatment effectiveness and detecting relapse.
- Assessing disease prognosis.
- Screening high-risk groups (e.g., hereditary predisposition).
Features and limitations
Elevated tumor marker levels do not always indicate cancer, and normal levels do not exclude it. Tumor markers can rise in inflammation and benign diseases. Therefore, diagnosis requires a comprehensive approach including instrumental methods and specialist consultation.
Significance of the test
- Early diagnosis and detection of tumors at preclinical stages.
- Assessment of response to treatment and therapy adjustment.
- Prediction of relapse and metastasis risk.
Tumor marker tests are an important tool in oncology that helps detect and monitor malignant processes but require comprehensive interpretation and cannot be used as the sole diagnostic method.