Tumour Markers in Cancer

Highly raised levels of a tumour marker can provide helpful information but inappropriate use can have economic implications and cause patients additional anxiety and distress

Role of Tumour Markers in Cancer Diagnosis

The only tumour markers cited in the NICE Urgent Cancer Referral Guidance that should be requested in Primary Care to support diagnosis of possible cancers are Ca-125 and PSA

• CA-125

CA-125 is elevated in 80% of patients with advanced ovarian cancer

May also be elevated in endometrial, fallopian tube, peritoneal, lung, pancreatic, oesophageal, gastric, hepatic and breast cancers and nonmalignant conditions such as benign cysts, fibroids endometriosis, pelvic inflammatory disease, cirrhosis, ascites, pleural and pericardial effusions and in menstruation and pregnancy

May be normal in 50% of early stage ovarian cancer

• Prostate-specific antigen (PSA)

See GP Gateway PSA page – follow link

• Monitoring of cancer and detection of Recurrence of Malignant Disease

There are many tumour markers, but their most valuable application of tumour markers has been in the monitoring of cancer and detection of recurrence of malignant disease following treatment.

Examples include:

Hormones: 

• Calcitonin – medullary thyroid carcinoma
• Beta- HCG –  Germ cell tumours, Gestational trophoblastic disease
• ACTH, ADH – small cell bronchial carcinoma

Enzymes: 

• Prostatic acid phosphatase – spread of prostatic carcinoma
• Bone alkaline phosphatase – primary and secondary osteoblastic tumours eg osteogenic sarcoma; (significantly, not multiple myeloma)
• Liver alkaline phosphatase – primary and secondary liver tumours; associated with localised intra-hepatic biliary obstruction

Tumour Antigens: 

• Carcinoembryonic antigen (CEA) – post-operative colorectal carcinoma; lacks the specificity or sensitivity to establish a diagnosis of cancer
• Alpha-feto protein (AFP) – hepatocellular carcinoma, teratoma
• Prostate specific antigen (PSA) -prostatic carcinoma

Monoclonal antibodies that detect glycoprotein antigenic determinants:

• CA 125 – ovarian carcinoma
• CA 15-3, CA 27.29 – breast carcinoma
• CA 19-9 – pancreatic, gastric, hepatobiliary carcinoma