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07. THE EFFECT OF ENVIRONMENT ON GASTRIC CARCINOGENESIS IN

NORFOLK.

Caygill C.P.J.* , Lavery K.*, Newell D.**, Thompson U.**,

Ail1 H.**, Diplock A.***.

* PHLS-CDSC, London NW9;

** PHLS-CARH, Salisbury, Wilts:

*** UMDS, Guy’s Hospital, London SEl.

Pockets of inteatinal type gastric cancer in Norfolk and in North Wales

have been reported by us previously; such cancers are thought to have an environmental etiology. Development of intestinal type gastric cancer is a multi stage process, an early stage of which is gastritis, the latter being associated with Campylobacter pylori (CP) infection. In a number of studies, Newell has shown a raised anti-CP titre in patients with gastritis and intestinal metaplasia. It has also been claimed that low selenium intake is correlated with an increased risk of gastrointestinal cancer. It was therefore decided to assay serum selenium (as a measure of selenium intake) and serum antibody to CP in a population living in the “pocket” of intestinal type gastric cancer and in a control “normal” area of Norfolk.

There was no significant difference between the high risk and the low risk areas in mean serum selenium level (87.0 (n=96) and 90.2 (n=106) ug/L respectively) although when only females were considered there was a etatisticelly significant difference (78.2 (n=48) vs 89.1 (n=58) ug/L; P<O.O5). In the high risk area the meen serum selenium level was significantly lower in females than in males (78.2 (n=48) and 95.8 (n=48) ug/L respectively; P<O. 05).

The mean anti CP antibody levels were also very similar between the high and low risk areas (13.0 f 26.9 ug/ml (n=lOO) and 12.2 + 25.2 ug/ml (n=251) respectively). Again, the difference in female antibody levels between the two regions was greater (11.8 ?r 28.3 ug/ml (n=50) and 6.8 f 15.9 ug/ml (n=116) respectively) without achieving significance. When only those with a raised antibody level were considered the percentages in the high risk area compared with the low risk area were also very similar.

We conclude, therefore, that the high risk of intestinal type gastric cancer in the Norfolk “pocket” was not associated with either e high prevalence of the gastritis precurser lesion or an abnormally low blood selenium level.