Benzodiazepine drug use and cancer risk: a dose–response meta analysis of prospective cohort studies

Conflicting results identifying the relationship between benzodiazepine drug use and cancer risk. Therefore, we conducted a dose-response meta-analysis of prospective cohort studies to clarify and quantitative assessed the relationship between benzodiazepine drug use and cancer risk. Up to July 2017, 22 original publications were included in current meta-analysis. Our results showed statistically significant association between benzodiazepine drug use and cancer risk (RR:1.25; 95% CI, 1.15-1.36). Subgroup analysis showed benzodiazepine using was associated with significantly a higher risk of breast cancer (RR:1.15; 95% CI, 1.05-1.26), ovarian cancer (RR:1.17; 95% CI, 1.09-1.25), colon cancer (RR:1.07; 95% CI, 1.02-1.13), renal cancer (RR:1.31; 95% CI, 1.15-1.49), malignant melanoma (RR:1.10; 95% CI, 1.03-1.17), brain cancer (RR:2.06; 95% CI, 1.76-2.43), esophagus cancer (RR:1.55; 95% CI, 1.30-1.85), prostate cancer (RR:1.26; 95% CI, 1.16-1.37), liver cancer (RR:1.22; 95% CI, 1.13-1.31), stomach cancer (RR:1.17; 95% CI, 1.03-1.32), pancreatic cancer (RR:1.39; 95% CI, 1.17-1.64) and lung cancer (RR:1.20; 95% CI, 1.12-1.28). Furthermore, a significant dose-response relationship was observed between benzodiazepine drug use and cancer risk (likelihood ratio test, P < 0.001). Our results showed per 500 mg/year, per 5 year of time since first using, per 3 prescriptions and per 3 year of duration incremental increase in benzodiazepine drug use was associated with a 17%, 4%, 16% and 5% in cancer risk increment. Considering these promising results, increasing benzodiazepine using might be harmful for health.