Cancer markers, also known as tumour markers, are substances produced by cancer cells or by the body in response to cancer. These markers can be found in the blood, urine, or tissue samples and can be used for various purposes, including screening, diagnosis, prognosis, monitoring treatment response, and detecting recurrence. However, it’s important to note that most tumour markers can be elevated in conditions other than cancer and are therefore not definitive on their own for a cancer diagnosis.
Here are some common cancer markers and the cancers they are typically associated with:
- Alpha-fetoprotein (AFP):
- Cancers: Liver cancer, germ cell tumors (e.g., testicular cancer)
- Note: AFP can also be elevated in non-malignant liver diseases, like cirrhosis and hepatitis.
- CA 125 (Cancer Antigen 125):
- Cancers: Ovarian cancer
- Note: It can also be elevated in non-malignant conditions such as endometriosis, menstruation, and pelvic inflammatory disease.
- CA 19-9 (Cancer Antigen 19-9):
- Cancers: Pancreatic cancer, gallbladder cancer, bile duct cancer, gastric cancer
- Note: It can also rise in non-malignant conditions like pancreatitis.
- CA 15-3/CA 27.29:
- Cancers: Breast cancer
- CEA (Carcinoembryonic Antigen):
- Cancers: Colorectal cancer, gastric cancer, pancreatic cancer, lung cancer, breast cancer
- Note: It can be elevated in non-malignant conditions such as inflammatory bowel diseases, pancreatitis, and in smokers.
- PSA (Prostate-specific Antigen):
- Cancers: Prostate cancer
- Note: Elevated levels can also be seen in benign prostatic hyperplasia (BPH), prostatitis, and after certain procedures like a prostate biopsy.
- Bence Jones Protein:
- Cancers: Multiple myeloma (when present in urine)
- Beta-2-microglobulin:
- Cancers: Multiple myeloma, chronic lymphocytic leukemia, some lymphomas
- Human Chorionic Gonadotropin (hCG):
- Cancers: Germ cell tumors (e.g., testicular cancer), choriocarcinoma
- LDH (Lactate Dehydrogenase):
- Cancers: A wide variety of cancers can elevate LDH levels, including lymphoma, leukemia, and germ cell tumors.
- Note: Many non-malignant conditions can also raise LDH levels.
- Calcitonin:
- Cancers: Medullary thyroid carcinoma
- Chromogranin A and Synaptophysin:
- Cancers: Neuroendocrine tumors
- NSE (Neuron-specific Enolase):
- Cancers: Small cell lung cancer, neuroblastoma
- BLCA-4:
- Cancers: Bladder cancer
While these tumour markers can provide valuable information, they are typically used in conjunction with other diagnostic tools, such as imaging and biopsy, to establish or confirm a diagnosis. Additionally, the utility of these markers for screening in the general population is limited, but they might be used for monitoring in patients with a known diagnosis or a high risk of certain cancers.