Relationship Between Leukotriene Receptor Antagonists on Cancer Development in Patients With Bronchial Asthma: A Retrospective Analysis.

BACKGROUND/AIM: An association between leukotriene receptor antagonists (LTRA) and cancer has been previously reported, but the relationship between LTRA use and cancer prevention remains controversial. This study aimed to clarify the cancer-preventive effect of LTRA in Japanese patients with bronchial asthma. PATIENTS AND METHODS: We obtained information from a large populationbased medical information database to analyze data on patients who were newly diagnosed with bronchial asthma between 2006 and 2015. Eligible participants were patients who were prescribed an LTRA for at least 30 days (LTRA users) and those who were not using LTRA (LTRA non-users) during the objective period. LTRA users and LTRA non-users were matched 1:1 using propensity scores. RESULTS: The 1:1 propensity score matching of LTRA users and LTRA nonusers facilitated the inclusion of 3,744 participants each, in these two subgroups. The results of the Cox proportional hazards model after adjustment for covariates showed no significant difference in the cancer risk between LTRA users and non-users [adjusted hazard ratio (HR)=0.83, 95% confidence interval (CI)=0.59-1.16]. The subgroup analysis showed no significant difference in the cancer risk between the LTRA low-cumulative dose group and LTRA non-users, or between the LTRA medium-cumulative dose group and LTRA non-users. In contrast, the LTRA high-cumulative dose group had a significantly lower risk of developing cancer compared with LTRA non-users (adjusted HR=0.57, 95% CI=0.33-0.98). CONCLUSION: LTRA use may prevent cancer in patients with bronchial asthma.

Leukotriene Receptor Antagonist Use and Dementia Risk in Patients With Asthma: A Retrospective Cohort Study.

BACKGROUND/AIM: Recent experimental studies have reported that leukotriene receptor antagonists (LTRAs) might protect against dementia. However, few clinical studies have examined this in humans. This study assessed whether the use of LTRAs can prevent the onset of dementia in humans. PATIENTS AND METHODS: A large population-based retrospective cohort study was conducted using a health insurance claims database in Japan, which included patients newly diagnosed with bronchial asthma between 2006 and 2015. Each of these patients that was LTRA user was matched with a randomly selected LTRA non-user according to age, sex, and bronchial asthma diagnostic year. RESULTS: There were 10,471 patients in both the LTRA user and the LTRA non-user group. Using Cox proportional hazards models, a significant reduction in the risk of developing dementia was observed in the LTRA user group compared to the non-user group (adjusted hazard ratio=0.42, 95% confidence interval=0.20-0.87, p=0.019). CONCLUSION: Our data suggest that the use of LTRAs may prevent the onset of dementia in asthmatic patients.