Cancer Markers Flashcards Preview

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Flashcards in Cancer Markers Deck (33)
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1

cancer definition

uncontrolled growth of cells to form either a tumor or spreading to many other body areas (metastasis)

2

cancer genetics

tumors from inherited or aquired genetic mutations that activate growth factors & oncogenes while inhibiting apoptosis, tumor suppression genes & genes that regulate cell cycles

3

what is seen with a metastasis cancer

less cell adhesion & more genetic changes

4

ideal tumor markers would:

be tumor specific
absent in healthy people
readily detectable
useful in both screening & diagnosis

5

screening tumor markers:

when there is one marker that aids in IDing w/ some certainty that you have the disease

6

prognosis tumor marker

more marker present the more cancer present
going into metastasis

7

monitoring tumor marker

use tumor marker as tool for monitoring patient after drugs, radiation, or chemotherapy

8

QC issues for tumor marker assays

antibodies used are variable
analytes are heterogenic
lack reference material; lack calibrators
kinetics unknown
lack standardized reference ranges

9

how to make tumor marker assays the most accurate as possible

test patient w/ same tumor marker from same kit & same methodology
use same reagent lot

10

common carcinomas

lung
breast
colon
bladder
prostate

11

common sarcomas

fat
bone
muscle

12

alpha-fetoprotein and liver cancer

used to monitor hepatocellular carcinoma (HCC)
used for diagnosis, staging, prognosis & monitoring treatment of HCC
>1,000 ng/ml is a poor prognosis for HCC

13

alpha-fetoprotein & testicular cancer

used to classify stage of disease & for monitoring treatment of testicular cancer
10-20% increase = stage I
50-80% increase = stage II
90-100% increase = stage III

14

AFP assay type

immunassays w/ 'sandwich' type assays

15

CA-125

cancer antigen 125
used to detect & monitor ovarian tumors
not used for mass screenings
contains putative transmembrane region & a tyrosine phosphorylation site
not normally seen in serum

16

stages of ovarian cancer & CA-125

50% increase = stage I
90% increase = stage II
>90% increase = stage III & IV

17

carcinoembryonic antigen (CEA)

oncofetal antigen- immunoglobulin that is part of group involved in apoptosis, immunity & cell adhesion
often expressed on tumor
not used for screening; used for monitoring & checking for re-occurrences

18

cancers that often express CEA

colorectal
lung
breast
GI

19

specificity of CEA

non-specific
associated w/ loss of cell adhesion (malignancy)

20

human chorionic gonadotropin (hCG)

secreted from trophoblasts of placenta to maintain the corpus luteum during early pregnancy
also elevates in trophoblast tumors, choriocarcinoma & germ cell tumors of ovary & testes

21

assay for hCG

hCG as a glycoprotein, has a alpha & beta subunit
look for free beta subunit as well as intact hCG forms

22

hCG can indicate?

ovarian cancer
diagnostic for testicular cancer
most useful for detection of gestational trophoblastic diseases
aggresstive lung cancer

23

4 distinct tumors of gestational trophoblastic disease

hydatidform mole
gestational trophoblastic neoplasms
choriocarcinoma
placental site trophoblastic tumors

24

cancer hormone markers

PTH
calcitonin
ACTH
Serotonin
Growth hormone
ADH

25

hormone receptors & cancer treatmenet

if hormone receptors are present - use hormone therapy
if not present - use chemotherapy

26

prostate specific antigen (PSA)

mild protease activity
glycoprotein from ch 19
has chromotrypsin-like & trypsin-like activity
a serine protease for kallikrein family
normal - should mostly be in the prostate
cancer- significant amount of PSA leaks into blood vessel

27

2 forms of PSA

free PSA
PSA complexed with alpha-1-antichymotrypsin (ACT) or alpha-2-macroglobulin (A2M)
most assays recognize 90% ACT & 10% free PSA or 100% free PSA

28

other causes of increased PSA

prostate infection
irritations
benign prostate hyperplasia
digital rectal exam prior to blood draw for PSA

29

enzyme cancer markers

alkaline phosphatase
lactic dehydrogenase isoenzymes
prostate specific antigen
neuron-specific enolase

30

suppressor p53

tumor suppressor protein that triggers cell apoptosis