Background

Evidence from in vivo and observational studies suggests anti-hyperlipidaemic and -diabetic medications (fibrates and glitazones respectively) may have a role in primary prevention and progression of brain tumours by targeting PPAR-α and -γ, respectively.

Method

We conducted a case-control and clinical cohort study within the UK Clinical Practice Research Datalink. We identified adults (18 years+) with primary or secondary brain tumours diagnosed between 2000-2016 prescribed either fibrates or glitazones and identified four controls based on age, sex and drug exposure duration. Multivariable logistic regression analysis estimated an association between drug exposure and brain tumour status. Cox’s survival models were used to investigate risk of mortality.

Results

1,916 cases were prescribed a fibrate and 445 a glitazone. Our analyses showed little evidence of an association between fibrates and risk or mortality of brain tumours (adjusted odds ratio for ever exposed PPAR-α 0.98, 95% CI 0.77 to 1.23; adjusted hazard ratio for ever exposed 0.91; 95% CI 0.76 to 1.09). We observed a reduced risk with a per-year increase in exposure duration for glitazones (adjusted odds ratio 0.88, 95% CI 0.81 to 0.96) but no major mortality benefit (adjusted hazard ratio 0.99, 95% CI 0.80 to 1.23).

Conclusion

Our results suggest longer duration exposure to glitazones is associated with a reduced risk of primary and secondary brain tumours but no large effect on mortality. We failed to find any strong evidence of a protective effect on risk or mortality for fibrate exposure. Further studies are required for replication and to provide more precise effect estimates.

Impact statement

Our analyses suggest that glitazones are associated with a decreased brain tumour risk and the results can help guide future research into drug re-repurposing for brain tumour treatment.