Tumor Markers Flashcards
1
Q
What are tumor markers? Why are they useful?
A
- glycoprotein molecules in the blood that are detected by monoclonal abs
each marker has a variable profiel of usefulness for:
- screening
- determining dx and prognosis
- assessing response to therapy
- monitoring for cancer recurrence
2
Q
How many tumor markers are currently in use? Where are these found?
A
- more than 20 being used
- found in blood, urine, or body tissue of some pts with cancer
- no universal tumor marker
- measurements can be useful when used along with x-rays or other test in detection of some types of cancer
3
Q
When are tumor markers used?
A
- helpt detect, dx, and manage some types of cancers
- elevated levels don’t suggest cancer
- measured b/f tx to help plan appropriate therapy
- markers are measured during cancer therapy
- markers are used to check recurrences
4
Q
What is the ideal tumor marker?
A
- highly specific: detectable in only one tumor type
- highly sensitive: non-detectable in physiological or benign disease states
- long lead time: sufficient time for alteration of natural course of disease
- levels correlate with tumor burden
- in reality no ideal tumor marker exists
5
Q
limitations of tumor markers?
A
- elevated marker level may be caused by a condition or diseaase other than cancer
- some marker levels may be high in people w/o cancer
- marker levels may vary over time
- almost every one has small amt of these markers
- levels tend to get higher only when a large amt of cancer is present
- some peoplt with cancer never have high levels
6
Q
Multiple factors to consider wtih tumor markers?
A
- as with other kinds of lab tests, diff labs may consider slightly diff marker levels to normal or abnormal
-mult factors:
person’s age and gender
which test kit the lab uses
how the test is done
7
Q
CA 15-3 and CA 27.29 cancer type, tissue analyzed, how it’s used, where else is it found?
When is it elevated?
A
- Cancer type: breast cancer
- tissue: blood (MUC1 gene)
- how used: assess whether tx is working or disease has recurred
- found also in: colon, gastric, hepatic, lung, pancreatic, ovarian, and prostate cancers
- elevated in 1/3 of women with early stage (1 or 2) and 2/3 of women with late stage breast cancer (3 or 4)
8
Q
CEA: cancer type tissue analyzed how is it used Where else is it found?
A
- colorectal and breast cancer
- tissue: blood ( less than 2.5 ng/ml nonsmokers and less than 5 ng/ml in smokers)
- how it’s used: check whethere colorectal cancer has spread, to look for breast cancer recurrence and assess response to tx
- also found: breast, lung, gastric, thyroid, lymphoma, melanoma
9
Q
When does sensitivity of CEA increase, when is it not useful? Main role?
A
- sensitivity increases with advancing tumor stage
- not useful in screening for colorectal cancer
- role is to follow pts for relapse after intended curative tx for colorectal cancer
10
Q
CA 19-9: Cancer types used for screening? Tissue? How is it used? Where else is it found? What levels predict mets?
A
- pancreatic***, gallbladder, bile duct, gastric cancer
- 89% specificity and sensitivity for pancreatic cancer
- tissue: blood (less than 37 units/ml)
- Used to assess if tx is working
- found also in colon, esophageal, hepatic cancers
- no value in screening
- levels above 1,000 units/ml predict presence of mets
11
Q
AFP: cancer types tissue How it's used found also in?
A
- liver ad germ cell tumors
(abnormal levels in 80% of pts with hepatocellular cancer) - tissue: blood (5.4 ng/ml)
- used to help dx liver cancer and follows response to tx, and assess stage, prognosis, and response to tx of germ cell tumors
- found also in: gastric, biliary, and pancreatic cancers
- screening is under debate
12
Q
B-HCG: Cancer types Tissue used for also found in? Following markers? Screening role?
A
- choriocarcinoma and testicular cancer
- tissue: urine or blood (less than 5 mlIU/ml)
- used to assess stage, prognosis, and response to tx
- found also in: GI cancers
- used with AFP for nonseminomatous germ cell tumors
- has no role in screening
- markers are followed q 1-2 months for a yr after tx, then quarterly for 1 yr
13
Q
CA 125:
cancer type
tissue
how is it used
also found in?
- Elevated most often with what type of ovarian cancer?
Good for screening? How often should levels be obtained?
A
- Ovarian cancer
- tissue: blood (less than 35 units/ml)
- used to help dx, assessment of response to tx and eval
- found in: endometrial, fallopian tube, breast, esophageal, and hepatic
- elevated most with epithelial ovarian cancer
- not a good screening marker
- helps guide therapeutic decisions
- levels should be obtained q 3 months for 2 yrs
14
Q
PSA: cancer type tissue how is it used also found?
A
prostate cancer
- blood (less than 4 ng/ml for screening, undetectable after radical prostatectomy)
- used to help dx, assess response to tx and look for recurrence
- also found in prostatitis, hypertrophy
15
Q
When do PSA levels return to normal? What drugs will decrease the PSA by half?
What level change is predictive of cancer?
A
- PSA levels will return to normal 6-8 wks after sxs
- taking Proscar or Avodart for 6 months will decrease PSA in half
- a velocity of 0.75 ng/ml per year or doubling time is predictive of cancer
