P2 BIOCHEMISTRY

Question 1

Biological substances synthesized and released by cancer cells or produced by the host in response to the presence of tumor.

Answer 1

Tumor Markers

Question 2

Types of tumor markers

Answer 2

• Tumor specific proteins.
• Non-specific proteins or markers related to malignant cells.
  -Cell specific proteins overexpressed in malignant cells.

Question 3

Example of tumor specific proteins

Answer 3

Philadelphia chromosome in CML

Question 4

Example of Non-Specific Proteins

Answer 4

oncofetal proteins

Question 5

oncofetal proteins are seen with which tumors

Answer 5

HCC , testicular , ovarian , GI tumors

Question 6

Example of Cell-specific proteins overexpressed in malignant cells

Answer 6

PSA

Question 7

uses of tumor markers

Answer 7

• population screening
• diagnosis
• staging & prognosis
• monitoring & recurrences

Question 8

Examples of tumor markers used in population screening

Answer 8

• AFP in liver cancer
• PSA (with DRE ) for prostate cancer

Question 9

give at least 2 reasons why tumor markers are nit sufficient to diagnose

Answer 9

1-Levels can be elevated in benign condition
2- Levels are not elevated in every person with cancer
3- The level of tumor marker may be elevated by more than one type of cancer

Question 10

HCG is tumor marker for

Answer 10

gestational trophoblastic tumors

Question 11

PSA is tumor marker for

Answer 11

prostate cancer

Question 12

CA125 is tumor marker for

Answer 12

epithelial ovarian cancer

Question 13

Thyroglobulin is used to

Answer 13

detect recurrence of thyroid cancer

Question 14

a 28-kD glycoprotein produced only in the epithelial cells of the acini and ducts of the prostatic ducts in the prostate.

Answer 14

Prostate Specific Antigen (PSA)

Question 15

is a serine protease that regulate seminal fluid viscosity, and is important for dissolving the cervical mucus cap, allowing sperm to enter.

Answer 15

Prostate Specific Antigen (PSA)

Question 16

forms of PSA

Answer 16

1- free PSA
2- complexed PSA

Question 17

The majority of PSA is of which type

Answer 17

complexed

Question 18

Free PSA + complexed PSA =

Answer 18

total PSA

Question 19

Cut of values of total PSA is

Answer 19

< 4 ng/ml

Question 20

measurements to increase the accuracy of PSA testing

Answer 20

1- Age-adjusted cut off values of PSA
2- PSA velocity (rate of rise over time)
3- Free PSA/ total PSA ratio

Question 21

PSA is expected to be undetectable after how many days after the radical prostatectomy

Answer 21

> 30 days

Question 22

Conditionn in which PSA values may be elevated

Answer 22

• Prostate infection
• irritation (prostatitis)
• Benign prostatic hyperplasia (BPH)
• Recent DRE
• recent ejaculation