Serum Tumour Markers
Nor Akmal bin Wahab
Below are information about serum tumour markers of which some are offered currently at PPSP-USM Chemical Pathology Diagnostic laboratories for your information and perusal.
1. Clinical applications of some commonly requested tumour markers :
Tumour marker Clinical Applications
AFP Diagnosis and monitoring of hepatocellular carcinoma and germ cell tumours
CA 125 Monitoring of ovarian cancer
CA 19-9 Monitoring of pancreatic cancer
CA 15-3 or BR 27.29 Monitoring of breast cancer
CA 72-4 Monitoring of gastric cancer
Calcitonin Diagnosis of medullary thyroid carcinoma
CEA Monitoring of colorectal cancer
HCG Diagnosis and monitoring of non-seminomatous germ cell tumours,
choriocarcinomas, hydatidiform moles, seminomas. Prognosis of germ
cell tumours
Oestrogen receptor Predicting response to endocrine therapy in breast cancer and , hence,
prognosis
PSA Diagnosis, screening and monitoring prostatic cancer
Squamous cell carcinoma
antigen Monitoring squamous cell carcinomas
Tissue polypeptide antigen
(TPA) Monitoring bladder and lung cancer
2. Pre-analytical considerations when measuring tumour markers
Timing of specimen collection A pre-treatment/management specimen should be collected.
Specimens can be taken at any time of the day as there is no
strong evidence of diurnal variation for most tumour markers.
Timing post-operatively, e.g. CA 125 may be increased by
peritoneal trauma.
Avoid blood sampling for CA 125 during menstruation.
Prostatic biopsy, transurethral resection of the prostate,
catheterisation , acute urinary retention , prostatitis, digital rectal
examination and post-ejaculation may all raise serum PSA levels.
Blood should be taken before any manipulation of the prostate.
Effect of other treatment/
medication Immunometric methods maybe vulnerable to interference from
antibodies (HAMA). Previous treatment with monoclonal
antibodies should be noted on the request form.
Effect of renal failure/impairment Published reports suggest inappropriately elevated results may
occur for some tumour markers , e.g. CEA and cytokeratins.
Effect of cholestasis May elevate serum CA 19-9 levels
Contamination with saliva May increase concentrations of CA 19-9 and CEA
Stability of specimen on storage Generally stable. Separation of serum from clot and storage at
4 C (short term) or -30 C (longer term) is desirable as soon as
possible.
For PSA, separation of serum and storage at 4 C or - 30 C is
desirable as soon as possible, and preferably within 3 hours of
sampling, especially if PSA is measured. For long term storage
specimens should be stored at - 70 C
3. Post analytical requirements of tumour marker service
A. Factual requirements :
Clinical information Encouraging clinicians to provide brief clinical information is essential if
any interpretations is to be provided and may help identify occasional
laboratory errors
Appropriate reference range Reference ranges for tumour markers are usually most relevant for cancer
patients pre- and immediately post-initial treatment. Subsequently , the patient's own baseline provides the most important reference for interpretation of results.
Knowledge of what
constitutes a significant or
clinically relevant change Should include both biological and analytical variation. A confirmed increase or decrease of + 25 % is frequently considered to be clinical significance.
B. Reporting requirements
Provision of full cumulative reports is helpful since it is always the trend in tumour marker concentrations that is most informative.
Minimal clinical details should appear on the report to facilitate interpretation. Graphical representations may also be very helpful.
Good communication between laboratory and clinical staff facilitates appropriate use of these and other tests.
References :
1. Witliff JL, Kaplan LA (eds.) Guidelines for the analytical performance and clinical utility of tumour markers. NACB : Rye Brook , New York 1998.
2. Tumour Marker Expert Panel (ASCO). Clinical practice guidelines for the use of tumour markers J. Clin Oncol 1996 ; 14 : 2843 - 2877.
Thank you
Wassalam and best regards
Nor Akmal bin Wahab
Assoc. Professor and Head of Chemical Pathology Department
School of Medical Sciences
Universiti Sains Malaysia
Kelantan Brach Campus
21/11/00 @ 12.52 pm
Alan Teh
CA19-9 in their "screening health packages"??
"Nor Akmal bin Wahab" <ak...@kb.usm.my> wrote in message
news:4.3.0.20001121...@kb.usm.my...
Nor Akmal bin Wahab
Serum tumour markers are biomolecules such as proteins , peptides and
antigens which
are expressed on cell surfaces such as the mucins CA 125 and CA 19-9 and
the carcino-embryonic
antigen (CEA) which you mention.
The available serum tumour markers lack sensitivity and specificity and are
thus not used in "screening
health packages" except for AFP (for hepatocellular carcinoma & germ cell
tumours) , Calcitonin ( for
medullary thyroid carcinoma) , PSA (for prostatic cancer) and HCG (for germ
cell tumours) which may be use for diagnosis in selected group of patients.
PSA may be used for screening prostatic cancer and not the others which is
generally used for monitoring and in some cases in prognosis and staging
germ cell tumours (eg. HCG, LDH and AFP).
Normal levels of serum tumour markers does not necessarily exclude a
malignancy. A tumour may lose its tumour marker in cases of chemotherapy.
Generally serum tumour markers are of value in monitoring response to
treatment , as in assessing whether surgery has been successful in removing
a tumour completely or if there has been a response to chemotherapy.
Wallahualam - Allah/GOD knows best.
Thank you and best regards
Nor Akmal Bin Wahab
USM Medical School
22/11/00 @ 10.36 am
At 07:02 AM 22-11-2000 +0800, you wrote:
>What do you think of laboratories which include markers like CEA, CA125,
>CA19-9 in their "screening health packages"??
>
>"Nor Akmal bin Wahab" <ak...@kb.usm.my> wrote in message
>news:4.3.0.20001121...@kb.usm.my...
>Assalamualaikum wrt and Greetings to all
>
>1. Clinical applications of some commonly requested tumour markers :
>
>Tumour marker Clinical Applications
>
>CA 125 Monitoring of ovarian cancer
>CA 19-9 Monitoring of pancreatic cancer
>CEA Monitoring of colorectal cancer
-----
To unsubscribe, send 'unsubscribe medibase' to majo...@jaring.my.
Archives of this list can be found at ftp://ftp.jaring.my/pub/archives/medibase/