Tumour markers: Definition
Tumour markers are specific molecules (usually glycoproteins) that may be found in higher concentrations in the serum, tissue, or urine in patients with certain cancers
Tumour markers can be used:
- In diagnosis
- In monitoring
Tumours markers IN DIAGNOSIS
Tumour markers are insufficiently sensitive or specific to be diagnostic in isolation.
In carefully selected patients, in whom cancer is suspected, highly raised levels of
a tumour marker may be helpful:
• alpha-fetoprotein (alphaFP) and human chorionic gonadotrophin (hCG) in testicular/
germ cell tumours.
• CA 125 in combination with USS and menopausal status.
• alphaFPin those at high risk of hepatocellular carcinoma.
• PSA >100ng/mL usually indicates metastatic prostate cancer.
Tumour markers IN MONITORING
The main value of tumour markers is in monitoring patients known to have cancer. This includes:
- Course of disease
- Effectiveness of treatment
- Detection of cancer recurrence
Screening for cancer: UK screening programmes
- Mammography every 3yrs (47-73 yrs)
- Cervical smears every 3-5 yrs (25-64 yrs)
- Men and women aged 60-74 yrs are offered faecal occult blood testing every 2 yrs.
Screening for cancer: PSA
- Most men with prostate cancer will have a high prostate specific antigen (PSA).
- The higher the PSA, the more likely cancer.
- However PSA = non-specific.
It is also raised in the following:
- Benign prostatic hyperplasia (BPH)
- BMI < 25
- Recent ejaculation
- Recent rectal examination
- Prostatitis
- UTI
- 76% of patients with a raised PSA do not have cancer.
- About 1 in 800 men avoid death from prostate cancer as a result of PSA screening.
- But screening also picks up many cancers that will never be fatal.
- Population screening for prostate cancer is not recommended.
- Despite this, any patient >50 yrs (or >45 yrs if high risk) can request PSA testing in primary care.
Tumour marker: Alpha-fetoprotein
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Germ cell/testicular, Hepatocellular
Use: Diagnosis, monitoring treatment, detecting recurrence
Other associated cancers: Colorectal; gastric; hepatobilliary; lung
Associated benign conditions: Cirrhosis; pregnancy; neural tube defects
Tumour marker: Calcitonin
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Medullary thyroid
Use: Diagnosis, monitoring treatment, detecting recurrence
Other associated cancers: None known
Associated benign conditions: C-cell hyperplasia
Tumour marker: Cancer antigen (CA125)
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Ovarian
Use: Monitoring ovarian cancer. Prognosis after chemotherapy
Other associated cancers: Breast; cervical; endometrial; hepatocellular; lung; non-Hogdkin’s lymphoma; pancreatic; medullary thyroid carcinoma; peritoneal; uterine
Associated benign conditions: Liver disease; cystic fibrosis; pancratitis; urinary retention; diabetes; heart failure; pregnancy; SLE; sarcoid; RA; diverticulitis; IBS; endometriosis; fibroids
Tumour marker: CA19-9
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Pancreatic
Use: Monitoring pancreatic cancer
Other associated cancers: Colorectal; gastric; hepatocellular; oesophageal; ovarian
Associated benign conditions: Acute cholangitis; cholestasis; pancreatitis; diabetes; IBS; jaundice
Tumour marker: CA15-3
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Breast
Use: Monitoring breast cancer
Other associated cancers: Hepatocellular, pancreatic
Associated benign conditions: Cirrhosis, benign breast disease, in normal health
Tumour marker: Carcinoembryonic antigen (CEA)
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Colorectal
Use: Monitoring adenocarcinomas
Other associated cancers: Breast, gastric; lung; mesothelioma, oesophageal, pancreatic
Associated benign conditions: Smoking, chronic liver disease, chronic kidney disease, diverticulitis, jaundice
Tumour marker: Human chorionic gonadotrophin (hCG)
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Germ cell/testicular, gestational trophoblastic
Use: Diagnosis, prognosis, monitoring of germ cell tumours
Other associated cancers: Lung
Associated benign conditions: Pregnancy
Tumour marker: Paraproteins
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Myeloma
Use: Diagnosis, monitoring treatment, detecting recurrence
Other associated cancers: None known
Associated benign conditions: None known
Tumour marker: Thyroglobulins
- Relevant cancer
- Use
- Other associated cancers
- Associated benign conditions
Relevant cancer: Thyroid (follicular/papillary)
Use: Monitoring treatment, detecting recurrence
Other associated cancers: None known
Associated benign conditions: None known
