The tumour markers CEA, AFP, CA 125 and CA 19-9 were analyzed in a group of
apparently healthy subjects in Kuwait. The sample (n=394) included both ge
nders in the population with a mean age of 38 (S.d. 120) years. The distrib
ution of CEA levels values was significant different (Mann-Whitney U test)
between Kuwaiti and non-Kuwaiti. The distribution of AFP levels was found t
o be the same in all groups. The distribution of CA 125 levels was signific
antly hr;higher in females than in males, both in Kuwaiti and non- Kuwaiti.
The distribution of CA 19-9 values was found to be significantly higher in
the Kuwaiti female group when compared to the males. The upper reference l
evel was defined as the 95 percentile of the normal values in each group. I
n the total population the reference level of AFP was 5.6 mu g/l and of CA
19.9 43kU/l. The reference level of CA 125 was 16U/l in males and 24 kU/l i
n females, respectively. The CEA reference level in Kuwaitis was 6.9 mu g/l
and in non-Kuwaitis 4.4 mu g/l. The results indicated the importance of de
termining the reference levels of tumour markers for each individual labora
tory. It was also emphasized that care should be taken on the impact of 95
percentiles of normal and benign disease groups.