Histamine-2-receptor antagonists and gastric cancer risk

Abstract

The relation between use of histamine-2-receptor (H₂-receptor) antagonists and gastric cancer risk was investigated in a case-control study in northern Italy. 563 patients with newly diagnosed, histologically confirmed gastric cancer were compared with 1501 controls who did not have neoplastic or gastrointestinal disorders. 36 (6·3%) cases and 59 (3·3%) controls had used H₂-receptor antagonists (cimetidine or ranitidine). The relative risk (RR) for ever-use was 1·8 (95% confidence intervals [Cl] 1·2, 2·7). The increased risk was restricted to patients who had started treatment with H₂-receptor antagonists within 5 years of the diagnosis of stomach cancer (RR 3·1; 95% Cl 1·8, 5·3). For first use of H₂-receptor antagonists 5-9 years previously the RR was 1·5 (95% Cl 0·7, 3·3), and for first use 10 or more years previously RR was 0·2 (95% Cl 0·03, 0·8). Although the incidence of gastric cancer was raised for the first few years after the start of treatment with H₂-receptor antagonists, this may reflect misdiagnosis of some early gastric cancers. The findings are against long-term persistence of an excess risk of gastric cancer in association with use of H₂-receptor antagonists.