We asked you this tough Oncology question. Thanks for all your guesses!
For those of you who answered with this reponse, you are right…
a. Beta HCG
c. AFP (alfa fetoprotein)
f. PSA (prostate specific antigen)
The other tests are not specifically designed as “screening tests” for patients. For example a man losing weight should not simply have a CEA, CA19-9 and Ca 125(!) checked as:
- there is no replacement for clinical examination and planned investigations
- “negative results” do not negate the need for further investigation
- “positive results” do not necessarily infer any diagnostic specificity.
A careful history, examination, investigations and clinical assessment is much more important than just requesting lots of tests.
PSA, HCG and AFP are different as a result of their sensitivity and specificity and relative prevalences of each of the conditions they act as “markers” for namely: prostate cancer, Choriocarcinoma and hepatoma.
The other tests are not validated as ‘cancer screening’ tools and should not be used in this way.
Commonly cited tumour markers:
|AFP||Hepatoma: also some seminomatous testicular tumours||Remember high risk populations including hepatitis virus and alcoholics|
|CEA||Colorectal cancer||Note its use in follow up rather than diagnosis|
|Calcitonin||Thyroid Medullary cancer||Diagnosis and follow up|
|Urinary Catecholamines||Phaeochromocytoma||Remember to consider this in patients presenting with palpitations and resistant hypertension|
|Protein Electrophoresis||Myeloma||Any questions that include the test “immunoglobulins and protein electrophoresis” is essentially looking for the monoclonal production of immmunoglobulin seen in myeloma|
|Ca 19-9||Pancreatic Cancer||Levels of >10,000 can correlate with metastatic spread in this aggressive tumour|
|Beta HCG||Choriocarcinoma||Almost ‘always’ elevated. Also elevated in germ cell tumours|
|Urinary 5HIAA||Carcinoid||Symptoms often imply metastases|