Exam 3 Tumor Markers

Question 1

Functions of tumor marker testing

Answer 1

• Detect and monitor cancer or effectiveness of treatment
• Markers are produced by tumor directly or as an effect of tumor on healthy tissue
• Concentration increases with tumor progression, highest levels when tumors metastasize

Question 2

Types of tumor markers

Answer 2

• Enzymes
• Serum proteins
• Hormones & metabolites
• Oncofetal antigens
• Receptors

Question 3

Characteristics of enzyme tumor markers

Answer 3

• Levels of certain enzymes correlate with tumor burden

Question 4

Examples of enzyme tumor markers

Answer 4

• ALP: bone, liver, intestine
• Amylase: pancreas
• LD: liver, lymphomas
• ACP: prostate

Question 5

Example of serum protein tumor markers

Answer 5

Multiple myeloma light chains found in urine

Question 6

Examples of hormone tumor markers

Answer 6

• ACTH: pituitary adenoma and ectopic lung tumor
• HCG: testicular tumor
• ADH: lung carcinoma
• Catecholamines: neuroblastoma

Question 7

Examples of oncofetal tumor makers

Answer 7

• Carcinoembryonic antigen (CEA) – colorectal

* Alpha-fetoprotein (AFP) – hepatocellular or testicular

Question 8

Examples of receptor tumor markers

Answer 8

• ERA – estrogen receptor assay
• PRA – progesterone receptor assay
- Presence indicates that tumor will likely respond to treatment

Question 9

Applications of tumor markers

Answer 9

• Screening populations at risk
• Diagnosis
• Prognosis
• Monitoring response to treatment
• Detection of recurrence

Question 10

Lab considerations for tumor marker testing

Answer 10

• Standardization between test methods or instruments is not as good as for other common assays
• Comparisons from two different assays can be dangerous due to differences in:
o Antibody specificity
o Assay design and diversity
o Lack of standard reference material
o Variation in reference ranges
• Example: variation in PSA results from two different assays
o Testing done on “access” was consistently higher (1.23x) than testing done on “centaur”

Question 11

Tumor marker methodology

Answer 11

• Immunoassay - most common
• Advantage: ability to automate testing
• May show the hook effect

Question 12

AFP tumor marker for:

Answer 12

Hepatocellular or testicular cancer

Question 13

CA-125 tumor marker for:

Answer 13

Ovarian tumors

Question 14

CEA tumor marker for:

Answer 14

Colorectal cancer

- > 10 suggestive of disease, > 20 assume metastasis

Question 15

hCG tumor marker for:

Answer 15

Testicular cancer

Question 16

PSA tumor marker for:

Answer 16

prostate cancer

• can be elevated in infection, irritate, benign prostate enlargement
• pts with prostate cancer have a lower % of free PSA

Question 17

PSA range

Answer 17

< 4ng/mL

Question 18

CA 15-3 tumor marker for:

Answer 18

metastatic breast cancer

Question 19

CA 27-29 tumor marker for:

Answer 19

elevated in recurrent breast cancer

Question 20

BRCA1 & BRCA2 tumor markers

Answer 20

hereditary breast-ovarian tumor syndrome

Question 21

Describe stage I cancer

Answer 21

localized primary tumor

Question 22

Describe stage II cancer

Answer 22

invasion of primary tumor through epithelium and into blood vessels

Question 23

Describe stage III cancer

Answer 23

migration of tumor into regional lymph nodes

Question 24

Describe stage IV cancer

Answer 24

metastasis and invasion of tumor to distant tissues