Circulating Tumor Markers: Basic Concepts and Clinical Applications

Question 1

What is the lifetime risk for women dying of cancer?
a. 19%
b. 23%
c. 43%
d. 59%

Answer 1

a. 19%

Question 2

Select the appropriate letter regarding tumor marker tests:
i. Screen for cancer
ii. Aid in staging of cancer
iii. Monitor response to therapy
iv. Detect recurrent disease
a. All of the above
b. i, ii, and iii
c. ii, iii, and iv
d. i, ii, and iv
e. iv

Answer 2

a. All of the above

Question 3

Tumor markers may be defined as
a. Biologic substances synthesized and released by cancer cells or
substances produced by the host in response to cancer cells
b. Analytic tests (e.g., immunoassays) used to mark cancer cells
c. Radioactive substances and chemicals used to help the physician
identify cancer cells
d. None of these

Answer 3

a. Biologic substances synthesized and released by cancer cells or
substances produced by the host in response to cancer cells

Question 4

Which of the following is an oncofetal antigen?
a. AFP
b. CA-125
c. β-hCG
d. CEA

Answer 4

a. AFP

Question 5

What are the major limitations of tumor markers?
a. Sensitivity and specificity
b. Cost
c. Turnaround time
d. Imprecision

Answer 5

a. Sensitivity and specificity

Question 6

The major clinical use for CA 15-3 is monitoring treatment response of
a. Ovarian carcinoma
b. Colorectal cancer
c. Prostatic cancer
d. Breast cancer

Answer 6

a. Ovarian carcinoma

Question 7

The most common immunoassays used to measure PSA detect which form of
the enzyme?
a. Total PSA
b. Free PSA
c. PSA complexed with α1-antichymotrypsin
d. PSA complexed with α2-macroglobulin

Answer 7

a. Total PSA

Question 8

Which of the following enzymes is commonly used as a tumor marker?
a. LD
b. Lipase
c. PSA
d. ALT

Answer 8

a. LD

Question 9

A tumor marker used in the assessment of choriocarcinoma or hydatidiform
mole is
a. β-hCG
b. CEA
c. AFP
d. IgG

Answer 9

a. β-hCG

Question 10

A serum PSA is used for all of the following except
a. Diagnosis
b. Screening
c. Monitoring response
d. Detecting recurrence

Answer 10

a. Diagnosis

Question 11

The following serum PSA measurements were obtained from two male
patients who were being monitored over an 18-week period.

Which of the following statements most accurately describes these data?

a. Patient A may have a more aggressive prostate cancer based on the
velocity of these measurements.
b. Patient A is most likely to have benign prostate cancer.
c. Patient B is most likely to be experiencing an inflammatory reaction,
and this is largely contributing to the elevated PSA above 100 ng/mL.
d. Patient B may have a more aggressive prostate cancer based on the
velocity of these measurements.
e. Answers a and c most accurately describe these data

Answer 11

d. Patient B may have a more aggressive prostate cancer based on the
velocity of these measurements.

Question 12

. When measuring tumor markers in the clinical laboratory, which of the
following has been reported to contribute to 30% to 70% of the total
amount of error?
a. Preanalytical errors
b. Analytical errors
c. Hook effect
d. Using different immunoassay methods
e. Not comparing lot numbers between ELISA kits

Answer 12

a. Preanalytical errors

Question 13

Which of the following methods is commonly used to measure endocrine
metabolites?
a. Protein electrophoresis
b. Immunoassays
c. HPLC
d. Electrochemistry
e. Gas chromatography

Answer 13

c. HPLC