Cancer of the Oesophagus in Transkei: An Investigation into the Dietary and Social Habits of the People of Transkei with the Intention of Casting Light on the Aetiology of Cancer of the Oesophagus within the Region

Transkei is a region of very high incidence of Cancer of the oesophagus (CO). Enquiry within the community revealed an unusual number of potential causes of injury to the oesophagus, the prevalence and extent of which were confirmed in opportunistic studies by questionnaire. The statistical relationship between CO and a large nunmber of potentially important factors in dietary and social habits was determined by iterative development of questionnaires for both CO patients and controls, culminating in a case-control study of 100 pairs. In the case-control study the following were significant: smoking, consumption of Solanum nigrum, consumption of Chenopodium album and use of traditional medicines were positively associated with CO; number of sheep kept, and total bought dietary fat were negatively associated with CO. Conditional logistic regression analysis of significant factors revealed relative risks of 3.6 for consumption of Solanum nigrum and 2.6 for smoking, both risks being significant. The wild vegetable Solanum nigrum has been identified as a probable carcinogen in Transkei, and a theory of pathogenesis is described which involves nutritional predisposition due to the staple diet, and carcinogenesis by substances which include tobacco and Solanum nigrum

24-Hour Measurement of Gastric pH in Rural South Africa

Background. Previous studies have established norms of 24-hour gastric pH profiles for western countries. This study was designed to establish the pattern for a rural African population with a high incidence of oesophageal cancer. Methods. After lower oesophageal manometry a probe was placed 10 cm distal to the lower oesophageal sphincter. We carried out 24-hour ambulatory monitoring of gastric pH on 59 healthy subjects. This was satisfactorily completed on 26 female and 18 male (age 21–64, median 35) subjects in the Transkei region of South Africa. Results. The mean 24 hour gastric pH was 2.84 and the mean night-time pH was 3.7. 40 volunteers recorded a night-time pH reaching over 4. 33 volunteers recorded a night-time pH over 7. Night-time alkalinisation was present for 136.4 minutes (25th centile 22.8, 75th centile 208.1) at pH4 or over, and 79.3 (2.5, 122.7) minutes at pH7 or over. Episodes of rapid alkaline rise were 17 (10, 47). 21.1% of these occurred while supine. 35 of 36 tested subjects were positive for H. pylori IgG. Conclusion. Gastric alkalinisation is common in Transkei, at a higher pH than that reported in other studies, and is sustained longer. Nighttime alkalinisation is frequent. This suggests a high level of duodenogastric reflux