Histamine‐2 receptor antagonists and risk of lung cancer in diabetic patients – an exploratory analysis

Abstract

Histamine-2 receptor blockers (H2RBs) might have anti-tumorogenic effect, but the clinical effect on lung cancer occurrence was unclear. A total of 640,173 type 2 diabetic patients were identified from the Taiwan National Health Insurance claims database in 2000. Patients were followed from cohort entry to the earliest of cancer diagnosis, death, disenrollment from the national health insurance, or 31 December 2007. For each participant, H2RB use during the follow-up period was ascertained from the outpatient pharmacy prescription database. Patients with incident squamous cell carcinoma (SCC) and adenocarcinoma were included as cases and up to four age- and sex-matched controls were selected by risk-set sampling. Conditional logistic regression models were applied to estimate the association between H2RBs and lung cancer incidence. A total of 1182 incident SCC and 2345 adenocarcinoma cases were identified, and 13,108 matched controls were selected. An increased risk was observed for H2RBs use <1 year with adjusted OR of 1.33 (95% confidence interval (CI): 1.22–1.44). After excluding all exposures occurring in the year before lung cancer diagnosis, H2RBs use with cumulative dosage ≥ 360 “defined daily doses” was associated with a significantly decreased risk of lung cancer (OR: 0.60; 95% CI: 0.38–0.96). When we stratified on types of lung cancer, the protective association of higher cumulative use of H2RBs seemed more evident for lung adenocarcinoma, with an adjusted OR of 0.49 (95% CI: 0.26–0.90). Higher cumulative use of H2RBs might be associated with a reduced risk for non-small cell lung cancer in diabetic patients.