Gastric cancer in a south Wales valley.

The most recent paper about gastric cancer in south Wales is that by Craven et al who covered the extensive publications on the subject, noting, for example, the pronounced social class relation and the high SMRs in certain occupational groups such as miners.1 They also discuss the paper by Stukonis and Doll, which suggests that hard work and a healthy appetite are more probable aetiological factors than specific occupational risks.2 The results of Craven et al, however, based mainly on cancer registration rates show miners with by far the highest registration rates for gastric cancer when compared with other occupations. There was, therefore, every reason to explore the hypothesis that exposure to coal dust might play a part in the aetiology of gastric cancer in Wales. The 30 year follow up of the men in the Rhondda Fach, consisting of non-miners and miners of whom 99-9% were carefully followed up for 30 years, provided an excellent data base for testing the hypothesis.3 Expected deaths for gastric cancer were calculated using the death rates for England and Wales for the same period. Statistical significance of the differences