Tumor Markers Flashcards
Hook Effect - A very ___ concentration of an analyte gives a falsely ___ result
-Very high concentration of an analyte gives a falsely LOW result
What is the mechanism of the Hook Effect?
-How can this be overcome
High concentration exceeds the binding capacity of both the binding capture antibodies and the signal bearing antibodies, preventing their association.
*If the sample is sufficiently diluted, the assay will give an appropriate result
What are considered indications for prostate needle biopsy?
-PSA >4 ng/mL
or
-Abnormal DRE
(controversial)
What percentage of men with elevated PSA (>4 ng/mL), have prostate cancer?
30-40%
What is true regarding PSA and race?
Levels are significantly higher in Blacks
T/F: Many men with prostate cancer have serum PSA <4.0 ng/mL.
True
-Poor Sensitivity
Fecal occult blood testing:
-Guaiac blood testing mechanism
Hemoglobin has endogenous peroxidase activity that is capable of oxidizing guaiac in the presence of hydrogen peroxide to a blue colored product.
Fecal occult blood testing - Guaiac blood testing:
- False-Positives
- False-Negatives
False Positives:
- NSAID use
- Consumption of heme (Meat)
- Consumption of peroxidase (turnips,horseradish)
Carcinoembryonic Antigen (CEA): -High preoperative CEA
Worse overall outcome
CEA may be elevated in what cancers? (8)
- GI
- Gastric
- Breast
- Pancreatic
- Lung
- Medullary Thyroid
- Cervical Adenoca
- Urothelial
What neoplasms are associated with elevated (cancer antigen) CA-125?
Nonmucinous Epithelial Ovarian neoplasms
CA27.29 (aka BR27.29) and CA15-3:
- protein product of what gene?
- Elevated in what?
- MUC1 gene
- Advanced stage breast cancer (both elevated in 60-70%)
What is the marker for pancreatic adenocarcinoma; elevated in 80% at presentation?
CA19-9
Who does not produce CA19-9?
Lewis negative patients
Where is alpha-fetoprotein (AFP) normally synthesized? (3)
- Yolk sac
- Fetal Liver
- Fetal GI tract
What NONneoplastic conditions are associated with an elevated AFP? (3)
- Pregnancy (normal)
- Cirrhosis
- Hepatitis
What neoplastic conditions are associated with an elevated AFP? (2)
- Yolk Sac tumors
- Hepatocellular Carcinomas (Most)
What conditions are associated with an elevated Human Chorionic Gonadotropin (HCG)? (4)
- Preganancy
- Gestational Trophoblastic Disease
- Choriocarcinoma
- Dysgerminoma/Seminoma (15%)
What tumor marker is elevated whenever there is increased cell death?
beta2-microglobulin
B2-microglobulin is an independent prognostic factor in what?
Multiple Myeloma
Alkaline Phosphatase:
- Indication of what?
- Elevated in what conditions
- Sensitive test for what?
- Osteoblastic activity
- Osteogenic Sarcoma or Bone Mets
- Sensitive test for Hepatic Metastases
What do carcinoids produce (generally)?
-Metabolite that is excreted into urine
Serotonin (5-HT)
-5-Hydroxyindoleacetic acid (5-HIAA)
GI Carcinoids produce?
- Foregut (3)
- Midigut (1)
- Hindgut (1)
Foregut
- Histamine
- Catecholamines
- 5-Hydroxytryptamine (5-HTP)
Midigut
-Serotonin (5-HT)
Hindgut
-Nonsecretory
Markers for Medullary Thyroid Carcinoma (2).
- Calcitonin
- CEA
Norepinephrine metabolism.
Norepinephrine - Normetanephrine - Vanillylmandelic acid (VMA)
Epinephrine metabolism.
Epinephrine - Metanephrine - Vanillylmandelic acid (VMA)
What is elevated in most cases of Neuroblastoma? (2)
Urine:
- Vanillylmandelic acid (VMA)
- Homovanillic acid (HVA)
Homovanillic acid (HVA) is the final metabolic product of what?
DOPA and dopamine
What are the nonspecific markers for Neuroblastoma that are used to follow disease activity? (3)
- Neuron Specific Enolase (NSE)
- Lactic Dehydrogenase (LDH)
- Ferritin
What is the Urine marker test for Urothelial Carcinoma?
- Test name
- Protein detected
- How is it released
- NMP22 (Nuclear Matrix Protein 22)
- NuMA (Nuclear Mitotic Apparatus)
- Released from nuclei of tumor cells when they die
What does the Bladder Tumor Antigen (BTA) test detect?
Complement factor H/related proteins
-CFH/CFH-rp
*in URINE
