THE ROLE OF TWO TUMOUR MARKERS – SQUAMOUR CELL CARCINOMA
ANTIGEN AND CARCINOEMBRYONIC ANTIGEN IN THE MONITORING OF PATIENTS
WITH CARCINOMA OF THE CERVIX UTERI MANAGED AT KENYATTA NATIONAL
HOSPITAL
DR. WARAMBO B.A (MBCHB)
Supervisors:
1. PROF. ORINDA D.A.O (B Pharm, PhD)
DEPARTMENT OF CLINICAL CHEMISTRY
2. PROF.KIGONDU C.S (BSc, PhD)
DEPARTMENT OF CLINICAL CHEMISTRY
3. DR. MUTUNGI A. (MBChB, MMed Obs/Gyn)
DEPARTMENT OF OBSTETRICS AND GYNAECOLOGY
4. DR. RANA F.S. (MBChB, MMed Path)
DEPARTMENT OF PATHOLGY
Degree: MMed Pathology
1998
SUMMARY
The serum levels of two tumour markers, squamous cell carcinoma antigen (SCCA) and
carcinoembryonic antigen (CEA) were measured in 75 patients with primary cervical cancer to
determine the correlation with the clinical presence of tumour and response to radiation therapy
and also in 75 control subjects.
The results showed that 76% (57/75) of the patients with malignant disease had elevated (greater
than 2.5ng/ml) pre-therapeutic levels of SCCA and 100% (75/75) of the control subjects had
titres of this marker below the cut off of 2.5ng/ml. the mean titres of SCCA for the cases of
malignant disease was 20.9 ± 30.9ng/ml, significantly higher (p<0.001) than that recorded for the
control group of 0.3 ± 0.4ng/ml.
The positive predictive value of a single serum SCCA titre greater than 2.5ng/ml was 76% while
a value less than 2.5ng/ml was 77.4% specific for absence of disease.
The mean titres for stage I through IV were 0.8, 16.9, 25.7 and 14.2ng/ml respectively with an
overall higher mean for late disease than for early disease. Within the squamous cell variant the
expression of this antigen was related to degree of differentiation of the tumour cells with the
titres falling with loss of differentiation. None of the adenocarcinomas encountered were
seropositive for this marker.
Thirty three of the patients completed a course of radiotherapy during the study. They attained a
post treatment mean for SCCA of 2.6ng/ml which was significantly lower (p less than 0.001)
than their pre-therapeutic mean of 19.7ng/ml. Normalization of serum marker levels was
achieved in 73.9% (17/23).
On the other hand, 66.2% (49/74) of the patients with malignant disease had elevated (>
3.0ng/ml) titres of CEA while 86.6% of the control subjects had titres below the cut-off of
3.0gn/ml. The group mean titres of this marker for the cases was 26.2 ± 62.1ng/ml as against 2.1
± 1.6ng/ml for the controls. The positive predictive values of a single titre above 3.0ng/ml was
68.6% while a value less than 3.0ng/ml was 68% specific for absence of disease.
The association of this marker with disease stage was shown with mean levels for stage I, II, III,
IV recoded as 35.1, 15.2, 34.8 and 43.6ng/ml respectively. The overall mean post-treatment titre
of 10.6ng/ml, though above the cut-off value was significantly lower (p=0.005) than the pretherapeutic mean of 21.5 ± ng/ml. Only 20% (4/20) achieved normalization of marker levels
following radiation therapy.
While there was no relationship noted between the serum levels of this marker and tumour
differentiation in squamous malignancies, both adenocarcinomas encountered were seropositive
with a group mean of 10.6ng/ml.
It is concluded that of the two tumour markers studies, SCCA correlated well with disease status
in squamous cell carcimona of the uterine cervix and that its determination would be useful in
monitoring progression of disease and in evaluating response to radiation therapy. It would
provide a useful adjunct in the management of patients with this variant of cervical malignancy.
CEA was also seen to correlate with disease process in carcinoma of the cervix. However, this
correlation was weaker than that observed with SCCA. The small number of adenomatous
tumours encountered did not allow the behavior of either marker to be conclusively studied.