The present invention is to a method of treating cancer in patients in need thereof with an effective amount of cimetidine. Cimetidine has been found to inhibit the expression of E-selectin, the ligands of sialyl Lewis X and sialyl Lewis A antigen-bearing cancer cells are incapable of attaching to a vascular wall. The present invention has found that cimetidine inhibits metastasis in patients whose specimens stained strongly for sialyl Lewis X and sialyl Lewis A antigens.