Tumor Markers Flashcards

1
Q

Define Tumor Marker

A

Biomarker found in the blood or tissue and when elevated is linked to cancer

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2
Q

How are tumor markers produced?

A

Directly by the tumor or as an effect of the tumor on healthy tissue

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3
Q

Tumor markers can take the form of what molecule(s)?

A

Hormones, metabolites, receptors, enzymes, oncofetal antigens

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4
Q

Enzyme tumor markers

A

Clinically useful for monitoring the success of therapy and correlate to tumor burden

Elevated non specifically

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5
Q

Serum Protein tumor markers

A

Used to monitor cancer therapy

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6
Q

Beta-Macroglobulin

A

Is a serum protein tumor marker that is found on the surface of all nucleated cells

A non specific marker of high cell turnover that is common in tumors

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7
Q

Immunoglobulins

A

A serum protein tumor marker that provides a relatively specific measure of plasma cell production of monoclonal proteins in multiple myeloma

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8
Q

Endocrine Tumor Markers

A

Used in endocrine malignancies. It is valuable in diagnosing neuroblastomas, pituitary and adrenal adenomas

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9
Q

Oncofetal antigens

A

Expressed transiently during normal development

Turned on again in formation of tumors

CEA and AFP

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10
Q

Carbohydrate and cancer antigen tumor markers

A

Monoclonal defined antigens identified from human tumor extracts and cell lines

Best used for monitoring treatment of tumors that secrete these epitopes

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11
Q

Carbohydrate and cancer antigen tumor markers are antibodies that are directed towards what?

A

Specific carb or cancer antigens.

Best for monitoring treatment of tumors that secrete CA19-9, CA 15-3, CA27-29, and CA-125

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12
Q

Receptor tumor markers are non serological markers that help choose between __a__ and __b__ therapies

A

A) Endocrine
B) Cytotoxic

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13
Q

What characteristics make an ideal tumor marker?

A
  • Tumor specificity
  • Absent in healthy individuals
  • Readily detectable in body fluids
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14
Q

T/F:
Tumor markers are found in only cancer

A

FALSE:
Most are found in normal and benign cells as well as cancer

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15
Q

T/F:
Tumor marker concentration increases with tumor progression

A

TRUE

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16
Q

Highest level of tumor marker is with ___

A

Metastasis

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17
Q

What are the two major considerations for tumor marker measurement?

A

1) Lack of standardization makes comparison of serial results difficult

2) The wide range of tumor marker concentrations encountered clinically

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18
Q

Immunoassays

A

Common method that allows automation and is relatively easy to use.

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19
Q

What are three unique factors of immunoassays

A
  • Assay linearity
  • Antigen excess (hook effect)
  • Potential for heterophile antibodies
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20
Q

What is the Hook Effect

A

When analyte concentrations exceed the analytical range excessively and there is potential for antigen excess.

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21
Q

What should you do if you get a linear result in the immunoassay?

A

Dilute the specimen and analyze it again. Do not give linear results

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22
Q

What are common analyte concerns with tumor maker immunoassays?

A
  • Icterus
  • Lipemia
  • Hemolysis
  • Antibody cross-reactivity
  • Carry Over
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23
Q

What is commonly used to detect endocrine metabolites (small molecules)

A

High performance Liquid Chromatography (HPLC)

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24
Q

Extractions in HPLC are applied to column and separated by what?

A

Charge, size, and polarity

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25
Q

T/F:
HPLC is useful to detect hormones and metabolites secreted by tumors. It is helpful in diagnosis, therapeutic monitoring, and recurrence.

A

TRUE

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26
Q

What are the advantages to HPLC?

A
  • Not subject to Hook Effect
  • No lot-to-lot variation
  • No interference from heterophile antibodies
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27
Q

What are disadvantages to HPLC?

A
  • Labor intensive
  • More experience and skill required than automated
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28
Q

Immunohistochemistry and Immunofluorescence require what type of specimen?

A

Fine needle aspiration or biopsy. This is for solid tissue tumor markers. Uses colorimetric or fluorescent secondary antibodies to detect the presence or absence of antigens

29
Q

T/F:
Enzyme assays can be used to specifically identify a type of tumor

A

FALSE

30
Q

What are examples of enzyme assays?

A

ALP: bone, liver, leukemia, sarcoma

LDH: liver, lymphomas, leukemia

PSA: Prostate

31
Q

Which tumor marker is involved in regulating fetal onconic pressure?

A

AFP

32
Q

In what patients is AFP elevated?

A

Hepatocellular carcinoma (HCC) and germ cell tumors

33
Q

Seminomatous cancer

A

formed directly from malignant germ cells

34
Q

Nonseminomatous cancer

A

differentiate into embryonal carcinoma, teratoma, choriocarcinoma, yolk sac tumors

35
Q

What other conditions can AFP be elevated in?

A

Pregnancy, non-malignant liver disease, testicular cancer

36
Q

AFP is used with HCG to classify ____ tumors

A

nonseminomatous

37
Q

Which of the following is NOT a clinical application of AFP:

1) Primary testing for seminomatous cancer
2) monitor therapy
3) detect residual tumor
4) Monitor relapse
5) maternal screening
5) Neural tube defects and chromosomal abnormalities

A

1) seminomatous cancer.

AFP can help classify nonseminomatous cancer.

38
Q

When would CA 125 be elevated?

A

In patients with endometriosis, 1st trimester of pregnancy, or during menstruation

39
Q

CA125 is a serological marker for what?

A

Ovarian cancer

40
Q

T/F:
CA125 can distinguish between benign masses and ovarian cancer

A

TRUE

41
Q

CEA is expressed when?

A

During development and re-expressed in tumors

42
Q

CEA is used to aid the diagnosis, prognosis, and therapy monitoring of ___

A

Colorectal Cancer

43
Q

T/F:
CEA is only involved in immunity and cell adhesion

A

FALSE

CEA is involved in apoptosis, immunity, and cell adhesion

44
Q

T/F:
CEA is measured to confirm the successful removal of tumor burden

A

TRUE

45
Q

hCG is a dimeric hormone that is secreted by ___

A

trophoblasts

46
Q

hCG is elevated in what?

A

Trophoblastic tumors, mainly choriocarnicona and germ cell tumors of ovaries and testes

47
Q

Gestational trophoblastic diseases (GTDs) consist of what 4 distinct types of tumors?

A

Hydatiform mole

Persistent/invasive gestational trophoblastic neoplasia

Choriocarcinoma

Placental Site Trophoblastic tumors

48
Q

Why is total beta-hCG is the most helpful?

A

Because it detects both intact and free beta-hCG

49
Q

What is structure of PSA?

A

Glycoprotein that is produced in the epithelial cell of the acini and ducts of the prostate gland

50
Q

What is the function of PSA

A

Regulates seminal fluid viscosity. It is instrumental in dissolving the cervical mucus cap allowing sperm to enter

51
Q

The most circulating form of PSA is ___

A

Bound

52
Q

T/F:

Malignancy will have a higher % of free PSA

A

FALSE

Malignancy will have a lower % of free PSA

53
Q

Increases in PSA can be caused by what?

A
  • Prostate infection
  • Irritation
  • Enlargement
  • Recent ejaculation
  • DRE
54
Q

What are known interferences for PSA?

A

Hook effect and HAMAs

55
Q

CA 15-3 is normally expressed where?

A

Glandular or luminal epithelial cells

56
Q

What is Mucin 1 (MIC1)?

A

A transmembrane glycoprotein that is the most researched tumor associated antigen

57
Q

CA15-3 is useful in manging what type of cancer?

A

Breast cancer

58
Q

CA19-9 is useful in diagnosing and monitoring what type of cancer?

A

Serial pancreatic cancer

59
Q

When is CA19-9 elevated?

A

In GI malignancies and benign conditions such as pancreatitis and cholestasis

60
Q

Ig Free light chains are useful in monitoring what type of patients?

A

Patients without a M spike on SPE

61
Q

What chains are measured in FLC?

A

Kappa and Lambda ratio

62
Q

What conditions produce increased immunoglobulins?

A

Multiple Myeloma and Waldenstrom Macroglobulinemia

63
Q

How is serum kappa and lambda measured?

A

Nephelometry

64
Q

The following are the major clinical applications of what?

  • Minimizes need to quantitate or perform urine pelp
  • Provides DX value in plasma cell dyscrasias
  • Allows monitoring of patients who previously deemed to have non secretory myeloma
A

FLC

65
Q

HE4 is shown to be overexpressed in what type of cancer?

A

Ovarian cancer

66
Q

Why do you need to reject hemolyzed samples when testing NSE levels?

A

Because NSE levels are present in RBCs

67
Q

What does NSE aid in in terms of DX?

A

Helps differential DX of neurodegenerative disorders

68
Q

NSE is an auxilary test for what?

A

Small cell lung carcinoma

carcinoid tumors

pancreatic islet cell tumors

neuroblastomas