Does cimetidine improve prospects for cancer patients? A reappraisal of the evidence to date

Background: Evidence first appeared in 1988 that cimetidine as an adjuvant may improve the survival of severely ill gastro-intestinal cancer patients when given peri- or postoperatively. Since then, several studies have appea red which suggest an anticancer activity for cimetidine, a though few attem pts have been made to corroborate their findings in large, placebo-controll ed, double-blind studies. Method We reviewed the literature concerning cime tidine's potential anticancer activity, particularly with regard to gastro- intestinal cancers. Results: Most studies suggest that cimetidine may impro ve the outcome in cancer patients by a three-pronged mechanism involving (1 ) inhibition of cancer cell proliferation; (2) stimulation of the lymphocyt e activity by inhibition of T cell suppressor function, and (3) inhibition of histamine's activity as a growth factor in tumours. Conclusion: Bearing in mind the experimental evidence, as well as the potential I and excellent safety profile of cimetidine, more studies are required and justified to c larify cimetidine's protherapeutic activity.