The study reported on page 17 illustrates some of the frustrations of clinical trials. The rationale for undertaking a prospective trial of the use of ranitidine in gastric cancer was appropriate. A previous study from Tonnesen et al ¹ had demonstrated a survival benefit using cimetidine in patients with gastric cancer. This group of authors argued that cimetidine had an immunological effect which included inhibition of T suppresser activity and increased interleukin 2 production by lymphocytes.^{2 3}

Ranitidine has a similar effect: the Yorkshire GI tumour group began this study in 1989 to evaluate the potential effect of …