1 Tumour Markers Flashcards
What is an uncontrolled growth of cells that forms a solid mass or tumour referred to as?
Neoplasm
Cancer, broad term.
Can spread to other areas of the body.
What are the different tumour stages?
Stage I - localized
Stage II - invasion of tumour through epithelial cells
Stage III - migration of tumour into regional lymph nodes
Stage IV - metastasis and invasion of tumour into distant tissues.
What are the five reasons tumour markers are tested?
- Aids diagnosis in symptomatic patient.
- Cancer prognosis - clinical outcome
- Tumour stages, severity and spread
- Monitoring treatment
- Dectecting recurrence or remission
What are other things Doctors used in addition to tumour markers to assess cancer?
In addition to tumour markers, doctors also use the following to diagnose cancer:
- Clinical signs
- Symptoms
- Histology
What are the different types of testing for tumour markers?
- Immunological methods (use antigens to confirm cell types)
- Molecular methods (differentiate malignant from benign, personalized medicine, etc.)
- Biochemical methods (enzymatic)
Can you name at least 3 ideal Tumour Marker characteristics?
- Measured easily and reliably
- Cost effective
- High analytical sensitivity and specificity
- Quantifiable
- Reflects tumour burden
- Results influence patient care and outcome
Can a tumour marker be used to effectively screen asymptomatic populations?
No, although there are debate about some (e.g. PSA). Tumour markers are not seen as an effective screen in the asymptomatic population.
What are the different types of tumour markers?
- Enzymes - correlate with tumour burden
- Hormones - secreted by tumours (or cause excess secretion from endocrine tissues)
- Oncofetal Antigens - was once present in embryonic fetal tissue now in the cancer
- Cancer or Carbohydrate Antigens - specific antigens are related to cancers, e.g. CA 125, CA 15-3, etc.
- Proteins - monoclonal antibodies
- Oncogenes - genes that under certain circumstances can transform a cell into a tumour cell (age, chemical exposure, vrus, etc.)
What is the typical blood collection tube for tumour markers?
Lithium Heparin Plasma Separator Tube
What interfering substances should the technician be aware of when measuring tumour markers? What precautions can be taken?
When using immunoassays, erroneous results could occur if the patient is on high biotin doses.
Do not collect samples until at least 8 hrs after the last dose.
What does the tumour marker alpha fetoprotein assist in?
Assists in the management of patients with germ cell tumours or hepatocellular carcinoma.
Where is alpha fetoprotein synthesized?
Synthesized by the liver, yolk sack and the gastrointestinal tract of the fetus.
After birth, AFP concentrations decline and are not normally present in healthy adults.
How is alpha fetoprotein measured in the laboratory?
Plasma (sample type)
Immunoassay method.
What type of tumour marker is alpha fetoprotein?
Oncofetal antigen
What does carcinoembryonic antigen (CEA) used for?
Carcinoembryomic antigen (CEA) is used to:
- Monitor colorectal cancer treatment.
- Identify recurrence
- Aid in staging and assessing metastasis.