Lecture 8: Tumour Markers Flashcards

1
Q

Cancer cells present the following properties

A

1.spherical morphology

2.expression of fetal antigens, growth-factor independence

3.lack of contact inhibition, anchorage-independence

4.growth to high density.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Early stages of cancer

Progressive changes

A

In the early stages, the abnormally proliferating cells are usually restricted to the area in which the cancer originated.

Progressive changes in the cancer cells may allow them to escape from the primary site (metastasis), and cause damage to the body on a larger scale.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cause of cancer

A

Cancer arises from the mutation of a normal gene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are mutated genes causing cancer called?

A

Mutated genes that cause cancer are called oncogenes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A factor which brings about a mutation is called ____

A

A factor which brings about a mutation is called a mutagen.

A mutagen is mutagenic.

Any agent that causes cancer is called a carcinogen and is described as carcinogenic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Benign vs malignant tumours

A

Benign tumours do not spread from their site of origin, but can crowd out (squash) surrounding cells eg brain tumour, warts.

Malignant tumours undergo metastasis. They interfere with neighbouring cells and can block blood vessels, the gut, glands, lungs etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Process of metastasis

A

To form a secondary tumour, a tumour cell needs to leave the vessel system and invade tissue. The cell must attach itself to a vessel’s wall.

Once this is done, it can work its way through the vessel and enter the tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Normal cell division vs cancer cells

A
  1. DNA is replicated properly.
  2. Chemical signals start and stop the cell cycle.
  3. Cells communicate with each other, so they don’t become overcrowded.

1.Mutations occur in the DNA when it is replicated.
2. Chemical signals that start and stop the cell cycle are ignored.
3. Cells do not communicate with each other and tumours form.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a tumour marker?

A

anything present in or produced by cancer cells or other cells of the body in response to cancer or certainbenign conditions that provides information about a cancer, such as howaggressiveit is, whether it can be treated with atargeted therapy, or whether it is responding to treatment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Examples of macro-molecular tumour markers

A

Polypeptide
Protein
Nucleic acid
Enzyme
Hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe tumour markers for sensitivity and specificity

A

Produced exclusively by a cancer cell as a response to tumuor development
Sensitivity

Not exclusively by a cancer cell, but has enough to be distinguished from production by a normal tissue cell
Specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

An ideal tumour marker characteristics

A

High sensitivity
High specificity
Can be qualified
Safe
Convenience
Low price

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

2 Types of TM:
Describe what it is and its function

A
  1. Circulating tumour markers
    - can be found in the blood, urine, stool, or other bodily fluids of some patients with cancer. Circulating tumour markers are used to:

1.estimateprognosis
2.detect cancer that remains after treatment (residual disease) or that has returned after treatment
3.assess the response to treatment
4.monitor whether a cancer has become resistant to treatment

2.Tumour tissue markers
-found in the actual tumours themselves, typically in a sample of the tumour that is removed during a biopsy.
Tumour tissue markers are used to:

1.diagnose,stage, and/or classify cancer
2.estimate prognosis
3.select an appropriate treatment (eg, treatment with atargeted therapy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tumour marker in oncology

A

1.Screening
2.Diagnosis
3.Staging
4.Prognosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Screening: downsides of tumour markers

A

Tumour markers play a limited role for Tumour screening, because….
1.relatively low sensitivity
2.lack of specificity and relation to Tumour size

Inappropriate for the detection of small cancers

In some cases, Tumour markers can be equal to other examinations envisioned for screening
PSA & prostate cancer
calcitonin & medullary thyroid cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Staging: tumour markers importance

A

The tumour markers and medical imaging are complementary in the pre-therapeutic and post-therapeutic staging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Prognosis and tumour markers

A

The pre-therapeutic level of certain tumour marker can contribute a prognostic factor because of links with…
Metabolic activity
tumour size
Invasion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

During treatment high tumour marker levels..

A

correlate very well with the therapeutic result

19
Q

During monitoring: TM..

A

Contribute to a valuable mean and lead to suspicion for…
1.local or metastasis
2.curable recurrence
3.much earlier before clinical or radiological detection

20
Q

Cancer management: Purpose of TM

A

levels help determine the amount of cancer present.

21
Q

TM 4 dilemmas

A

1) tumour marker levels can be elevated in people with benign conditions;
2) tumour marker levels are not elevated in every person with cancer, especially in the early stages of the disease;
3) many tumour markers are not specific to a cancer
4) the level of a tumour marker can be elevated by more than one type of cancer

22
Q

When are AFP’s high

A

serum AFP concentrations remain low except during pregnancy, benign liver diseases, (hepatitis, cirrhosis), primary hepatocellular carcinoma, and certain germ cell tumours.

An elevated level of AFP strongly suggests the presence of either primary liver cancer or germ cell cancer of the ovary or testicle.

23
Q

Most important application of AFP test

A

The most important application of AFP testing in cancer management is for testicular cancer.

24
Q

Why montior the rate of AFP clearance after treatment?

A

Monitoring the rate of AFP clearance from serum after treatment is an indicator of the effectiveness of therapy.

25
Q

Purpose of AFP in pregnant women

A

The amount of AFP in the blood of a pregnant woman can help diagnose whether the fetus may have such problems as
1.spina bifida
2.anencephaly
3.Down syndrome
4.Chromosomal problems (trisomy)
5.Omphalocele

26
Q

2 Limitations of AFP

A

1.Increased circulating AFP concentrations may also occur in serum specimens from patients with gastrointestinal, pancreatic, and pulmonary cancers.

  1. AFP is not a screening test for cancer.
27
Q

CEA levels normally and abnormally (cause)

A

Protein normally found in very low levels in the blood of adults.

An oncofetal glycoprotein antigen.

Carcinoembryonic antigen (CEA) is a normal cell product that is over-expressed by adenocarcinomas, primarily of the colon, rectum, breast, and lung.

28
Q

Purpose of CEA Test

A

A CEA test is most used for colorectal cancer.

29
Q

CEA Test is used for ..

A

1.Determine how widespread cancer is for some types of the disease, especially colon cancer.

2.Monitor the success of treatment for colon cancer.

3.CEA levels may be measured both before and after surgery to evaluate both the success of the surgery and the person’s chances of recovery.

4.CEA levels may be measured during treatment with medicines to destroy cancer cells (chemotherapy).
This provides information about how well the treatment is working.

30
Q

CEA and its limitations

A
  1. Used after treatment to check for recurrence of colorectal cancer if the original cancer produced this protein before treatment.

2.Monitor therapy of patients with various types of malignancies

3.Measuring the amount of CEA in other body fluids, such as abdominal fluid (peritoneal fluid) or the fluid around the brain and spinal cord (cerebrospinal fluid, or CSF), can determine whether cancer has spread to that part of the body.

4.Other diseases, such as cirrhosis, and Crohn’s disease, may also raise CEA blood levels.

5.CEA levels are usually higher in smokers than in people who do not smoke.

31
Q

is the CEA blood test a reliable for diagnosing cancer or as a screening test for early detection of cancer.

A

No, only for monitoring

32
Q

PSA normal function

A

Its normal physiologic role is as a liquefying agent for seminal fluid; only a tiny amount leaks into the blood, therefore its normal serum level is usually very low.

33
Q

Elevated PSA levels usually mean…

A

have been associated with prostate carcinoma.

benign prostate conditions, such as prostatitis and benign prostatic hyperplasia (BPH), or with a malignant growth in the prostate.

Therefore high PSA = prostate cancer or a noncancerous condition such as prostatitis or an enlarged prostate.

34
Q

What factors impact PSA and how

A
  1. Age: Your PSA will normally go up slowly as you age, even if you have no prostate problems.

2.Medications: Some medicines may affect blood PSA levels. Tell your healthcare provider if you are taking finasteride (Proscar or Propecia) or dutasteride (Avodart).

These drugs may falsely lower PSA levels typically by half of what it would normally be.

35
Q

hCG normally found from?
High hCG means…

A

Human chorionic gonadotropin (HCG) is normally produced in increasing quantities by the placenta during pregnancy.

Elevated HCG levels may also indicate the presence of cancers of the testis, ovary, liver, stomach, pancreas, and lung.

36
Q

what does hCG screen for?

A

to screen for choriocarcinoma in women who are at high risk for the disease, and to monitor the treatment of trophoblastic disease.

37
Q

hCG also produced by ____ tumours

A

Tumours that develop from egg or sperm

38
Q

hCG tested for ____ in women and ____ for men

A

Therefore, hCG levels are usually tested in a woman who may have cancer of the ovaries or abnormal tissue growing in her uterus (molar pregnancy) instead of a normal fetus.

In a man, hCG levels may be measured to help determine whether he has cancer of the testicles.

39
Q

what is CA-125 and TM for what cancer?

A

A high-molecular-weight glycoprotein found on the surface of Mullerian and coelomic epithelial-derived cell types, and is the best knowntumour markerforepithelial ovarian cancer.

40
Q

A decrease in CA-125 during treatment means..

A stable/rise in CA-125 during treatment means..

A high in CA-125 after treatment means..

A

A decrease in the CA125 level during treatment usually means that the cancer is responding to treatment.

If the CA125 level stays the same or rises during treatment, it may mean that the cancer is not responding to treatment.

A high CA125 level after treatment is complete may mean that the cancer has come back (recurred).

41
Q

what is CA-153 and purpose
TM for what cancer? and stage of this cancer
High CA-153 means?

A

A high molecular weightmucin and may be used to monitor response to treatment, rising serum concentrations providing early indication of progression in some patients.

A protein made by a variety of cells, particularly breast cancer cells.

CA15-3 levels can be higher than normal with cancerous and non-cancerous conditions.

CA15-3 is most often increased in breast cancer that has spread to other parts of the body.

42
Q

CA-199:
where is it found?
TM for what cancer?
Why cant this test be used by itself?

A

It is a protein found on the surface of certain cancer cells.
It may be found in the blood when it is shed by cancer cells.

CA19-9 is commonly used as a tumour marker for some types of cancer of the pancreas.

But this test cannot be used by itself to find pancreatic or other cancers because:
CA19-9 is also found in healthy adults in small amounts in the pancreas, liver, gallbladder and lungs.

43
Q

Type of detection, cancer type(s) and clinical application for the biomarkers:
AFP
hCG
CA125
CA153
CA199
CEA
PSA

A

AFP:
Protein and core fucosylation
Germ cell hepatoma, testicular cancer
Diagnosis, staging, monitoring and detect recurrence.

hCG:
Protein alone
Testicular
Diagnosis, staging, monitoring and detect recurrence.

CA125
Protein Alone
Ovarian cancer
Prognosis, detecting recurrence, monitoring therapy

CA153:
Siaylated O-glycan on MUC1
Breast cancer
Monitoring therapy

CA199
SLE on mucin glycoproteins
Pancreatic cancer
Monitoring therapy

CEA:
Protein alone
Colon cancer
detecting recurrence, monitoring therapy

PSA: Protein Alone
Prostate Cancer
Screening, diagnosis (with rectal exam)