Tumor marker

Question 1

What is the primary function of testing Tumor marker? (1)
Give examples that Tumor marker is used for screening (3), diagnosis (3), and disease progression (3)

Answer 1

Most are for treatment & recurrence monitoring

Screening:
hCG(testicular cancer), Calcitonin(thyroid medullary), & PSA(prostate cancer)

Diagnosis:
insulin, gastrin, prolactin, CAT

Disease progression:
BRCA-1, Estrogen R, Progesterone R, cathepsin-D, Ph chr

Question 2

Name four Gene tumor markers (4)
Name two tumor suppressor gene (2)

Answer 2

retinoblastoma gene (RB gene)
Ph
Myc
p53 gene

BRCA
p53

Question 3

hCG is a Hormone tumor markers. Why IMA for hCG has Antibody targeting both intact & free β hCG? (1) Why hCG sometime increase after chemotherapy? (1) Suggest another marker that have synergistic effect in testicular cancer screening with hCG. (1)

Answer 3

In recurrence of testicular cancer, there is production of β-subunit without intact hCG

Slightly increase after chemotherapy due to tumor cell destruction

AFP, 70% for nonseminoma testicular cancer

Question 4

Name 6 Enzyme tumor markers (6)

Answer 4

CK-BB
GGT
AMY
Placental ALP
ALP & LDH

Question 5

RB gene

Answer 5

Missing = retinoblastoma
Mutation = various cancer

Question 6

Ph

Answer 6

CML, AML & ALL

Question 7

Myc

Answer 7

lung, breast, colon, stomach, leukemia, and lymphoma
tested on tissue instead of blood

Question 8

CK-BB

Answer 8

prostate cancer and SCLC

Question 9

GGT

Answer 9

Hepatoma

Question 10

AMY

Answer 10

Pancreatic cancer

Question 11

cancer monitored by Placental ALP (1)
Name 1 additional test to confirm lung cancer

Answer 11

Lung cancer, confirm in patient with Cushing syndrome caused by ectopic ACTH production

Question 12

Is ALP & LDH tumor markers? (1)

Answer 12

Yes, high ALP & LDH suggests various tumors

Question 13

Name 7 oncofetal antigen tumor markers (7)

Answer 13

AFP, CEA, PSA, CA125, CA153, CA199, SCCA

Question 14

cancer monitored by AFP (1)
Is it possible that other condition causes high AFP making it an invalid marker for cancer monitoring? (2)

Answer 14

Liver cancer (80%), yolk sac, testicular
usually >10X

Other than liver cancer, consider ovarian, testicular, breast, GI, and bladder cancers. Monitoring recurrence of liver cancer may not be valid in patient with multiple cancers.

Question 15

cancer monitored by CEA (1)
Can I use CEA for screening purpose? (2)

Answer 15

Colon cancer, also in breast, lung & stomach
For screening, use OB (80%), not CEA (60%), not AFP (5%)

Question 16

cancer screened by PSA (1)
Can a patient with that cancer has normal PSA? (2)
Is patient with high PSA means he has that cancer? (2)
At what levels of PSA would you recommend prostate biopsy? (2)

Answer 16

Prostate cancer

Yes, a cutoff of 4 ng/mL gives 60% sensitivity only, so patient having Prostate cancer is not always detected by PSA, although it is called a screening test

No, a high PSA specificity for Prostate cancer is 60% only, because PSA also increase in patient with Benign prostatic hyperplasia (BPH)

PSA > 10 ng/mL OR fPSA < 25%
In patient with prostate cancer, fPSA/total PSA ratio drops due to incomplete cleavage of PSA

Question 17

SCCA

Answer 17

Uterine cancer
Value of SCCA for diagnosis & prognosis remain controversial

Question 18

CA125

Answer 18

Ovarian cancer

Question 19

CA153

Answer 19

breast cancer

Question 20

Describe how Cathepsin-D, ER / PR, HER-2/neu (c-erb B-2 gene), and EGF-R helps in determining the prognosis of breast cancer (4)

Answer 20

High Cathepsin-D suggest higher chance of relapse

ER / PR + suggests responsiveness to tamoxifen therapy
ER- / PR+ = 15%
ER+/ PR+ = 75%

HER2 + suggests responsiveness to Herceptin therapy

EGFR+ suggests poor prognosis in general

Question 21

What is the difference between tamoxifen therapy & Aromatase inhibitor? (2)

Answer 21

tamoxifen targets ER while Aromatase inhibitor targets E
Aromatase inhibitor is recommended for postmenopausal women as it is 30% more effective, and E alteration has less toxic effect for them.

Question 22

CA199 (1)
Why some people have 0 CA199 regardless of cancer existence? (1)

Answer 22

Gastric, pancreatic, and colorectal cancer

CA199 is always Negative in Le(a-b-) phenotype as Le enzyme is required for CA199 synthesis

Question 23

Urine VMA, catecholamines, and metanephrines

Answer 23

Pheochromocytoma & neuroblastoma

Question 24

Chromogranin A

Answer 24

pheochromocytoma, neuroblastoma, and carcinoid tumors

Question 25

Urine 5-hydroxyindoleacetic acid (5-HIAA)

Answer 25

carcinoid tumors

Question 26

Urinary HVA

Answer 26

Neuroblastoma (75%)
Not in pheochromocytoma