talents_psa and cea as surrogate markers for cancer diagnosis

8/10/2019 Talents_psa and Cea as Surrogate Markers for Cancer Diagnosis

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EKUSILENI CLINICAL

LABORATORY

PSA AND CEA AS

SURROGATE MARKERS

FOR CANCER DIAGNOSIS

TALENTS MURAHWA

(BIOMEDICAL SCIENTIST)


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2007 EKUSILENI CLINICALLABORATORY 2

LAB & CANCER MANAGEMENT

What are tumor markers

Definition: -

A tumour marker is a biochemical indicator selectively

produced by the neoplastic tissue and released into

blood and detected in blood or in other body fluids.

It may be used to: -

Detect the presence of a tumour

Monitor the progress of disease Monitor the response to treatment


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Tumour Markers: - Classification

Class 1:Antigens unique to a neoplasm not sharedby other tumours of same histological type .

Class 2: Antigens expressed by many or most

tumours of a specific histological type and of other

histological type,

But not expressed by normal adult tissue.

Class 3:Antigens expressed by both cancer and

normal adult tissue.


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NATURE OF TUMOUR

MARKERS 1.Oncofetal antigens

Alpha Feto Protein

CEA

Pancreatic Oncofoetal Antigen

2.Proteins CaseinBy breast carcinoma

Ferritin- Leukaemia

3.Enzymes CreatinekinaseProstate tumour

Alkaline PhosphataseLungs tumour

Acid PhosphataseProstate tumour


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4. Receptors Oestrogen, Progesterone, Androgen

5. Polyamines

Spermine, Spermidine, Putridineleukemia,lymphoma, colorectal CA

6. Cell Markers

T cell marker, B cell marker-lymphoma

7. Ectopic Hormones

HCG, GH, Erythropoetin, Renin


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LOCAL LABORATORY TESTS ON OFFER

1.Alfa Feto Protein

2.CEA

3.PSA

ALPHA AMYLASE

LDH


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Alfa Feto Protein:-

Measurement of maternal serum and amniotic fluid levelsplay an important role in the screening for Foetal neural tube defects

Chromosomal abnormalities including Downs Syndrome.

Most measurements are done at 16 weeks of gestation. Raised maternal serum AFP levels are not specific for

neural tube defects.

Must be used in combination with other modalities such as

USG, amniotic fluid AFP and acetylcholine esterase.


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Alfa Feto Protein:-

Many fetal conditions are associated with

abnormal maternal serum AFP levels.

Elevated:

NTD, GI obstruction, Liver necrosis, Abdominal wall defects(Omphalocele, Gastroschisis), Sacrococcygeal tumour, Cystic

hygroma, IUGR, multiple pregnancies, renal anmalies.

Low:

Chromosomal trisomies (Downs syndrome),Gestational

trophoblastic diseae, IUD, placental defects, GA

underestimated, Foetal distress, Hydrops Foetalis, TOF,

Cyclopia.


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Alfa Feto Protein:-

After birth AFP usually falls, within 8 to 12 monthsof delivery to a very low conc.of 10mcg/ml andpersists at this low level throughout life.

Unexplained and persistent elevation of AFP in

nonpregnant state should be screened, as it maybe due to- Hepatocellular Ca, germ cell tumour, hereditary

persistence of AFP, viral hepatitis and cirrhosis .

In addition to its role in prenatal diagnosis, it isalso widely used in the diagnosis, therapeuticmonitoring and follow up of patients in germ celltumours.


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AFP

1. Dysgerminoma --

2. Endodermal Sinus tumour / +yolk sac tumour

2. Immature tetratoma +/-

4. Mixed germ cell tumour +/-

5. Choreocarcinoma --

6. Embryonal CA --

Germ Cell Tumours Producing

AFP


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CEA:-

It is a glycoprotein of mol.wt 200kda. Though it is a tumour marker for GI cancers, it is

also expressed by

malignant mucinous tumor (100%),

100% cases of atypical hyperplasia of endometrium,

60% cases of endometrial Ca,

50-80% cases of squamous cell of Cx,

75-100% cases of adenocarcinoma of Cx. It is also produced in pneumonia, hypothyroidism

and pancreatic tumours.


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PSA

Prostate-Specific Antigen (PSA)

A prostate-specific antigen (PSA) testmeasures the amount of prostate-

specific antigenin the blood. PSA is

released into a man's blood by hisprostate gland.
http://www.webmd.com/hw-popup/Prostate-specific-antigen-PSA-testhttp://www.webmd.com/hw-popup/Prostate-specific-antigen-PSA-testhttp://www.webmd.com/hw-popup/Prostate-glandhttp://www.webmd.com/hw-popup/Prostate-glandhttp://www.webmd.com/hw-popup/Prostate-specific-antigen-PSA-testhttp://www.webmd.com/hw-popup/Prostate-specific-antigen-PSA-testhttp://www.webmd.com/hw-popup/Prostate-specific-antigen-PSA-test


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Healthy men have low amounts of PSA in

the blood. The amount of PSA in the

blood normally increases as a man's

prostate enlarges with age. PSA may

increase as a result of an injury, a digital

rectal exam, sexual activity (ejaculation),

inflammation of the prostate gland (prostatitis), or prostate cancer
http://www.webmd.com/hw-popup/prostatitishttp://www.webmd.com/hw-popup/prostatitishttp://www.webmd.com/hw-popup/prostate-cancer-overviewhttp://www.webmd.com/hw-popup/prostate-cancer-overviewhttp://www.webmd.com/hw-popup/prostatitishttp://www.webmd.com/hw-popup/prostatitis


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PSA Why is it done?

Why It Is Done

The prostate-specific antigen (PSA) test is doneto:

Monitor prostate cancer and how it respondsto treatment. If PSA levels increase, the cancermay be growing or spreading. PSA is usuallynot present in a man who has had his prostate

gland removed. A PSA level that rises afterprostate removal may mean the cancer hasreturned or has spread.


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PSA

Prostate cancer often grows very slowly,

without causing major problems.

Detecting prostate cancer early and

treating it may prevent some health

problems and reduce the risk of dying

from the cancer. However, some

treatments for prostate cancer can causeother problems, such as


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PSA

Determine if cancer may be present when

other tests, such as a digital rectal exam,

are not normal. A PSA test does not

diagnose cancer, but it can be used along

with other tests to determine if cancer is

present.
http://www.webmd.com/hw-popup/Digital-rectal-examhttp://www.webmd.com/hw-popup/Digital-rectal-exam


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PSA

Check men for prostate cancer. Experts disagreeon the usefulness of PSA testing as a screeningtool for prostate cancer. If a PSA test is used forscreening, it is usually done for men older than

age 50 or for those at high risk for prostate cancer,such as men with a family history of prostatecancer, or for African-American men who have ahigher chance of developing cancer than othermen. Since other common medical conditions,such as prostatitis, can cause high PSA levels, aprostate biopsyis needed to confirm a diagnosisof cancer.
http://www.webmd.com/hw-popup/Biopsyhttp://www.webmd.com/hw-popup/Biopsy


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talents_psa and cea as surrogate markers for cancer diagnosis

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