Why is this important?
- Dapagliflozin use resulted in a higher number of bladder cancer events in randomized pre-marketing clinical trials compared to placebo, with events occurring soon following randomisation (range: 43–727 days). Subsequent post-marketing studies of SGLT2 inhibitors have had mixed results.
- Future studies are needed to assess the long-term risk.
Methodology
- An international multicentre study was conducted on two cohorts of adults with type 2 diabetes who were starting treatment with:
- SGLT2 (n=453,560) or GLP-1 RA (n=375,997) inhibitors;
- SGLT2 inhibitors (n=347,059) or DPP-4 inhibitors (n=853,186).
- Funding: Canadian Institutes of Health Research project grant.
Principle results
- SGLT2 inhibitors, versus GLP-1 RA:
- After pooling, 1,978 incident bladder cancer events were reported during 1,684,049 person-years of follow-up (crude incidence rate: 117.5 per 100,000 person-years). The median duration of follow-up was between 1.5 years and 2.2 years. No difference was observed in the risk of bladder cancer between the 2 treatments (corrected risk ratio [RRc] : 0.90; confidence interval [IC] at 95%: 0.81–1.00).
- SGLT2 inhibitors versus DPP-4 inhibitors:
- After pooling, 4,164 incident bladder cancer events were reported during 2,755,807 person-years of follow-up, corresponding to a crude incidence rate of 151.1 per 100,000 person-years. The median duration of follow-up was between 1.6 years and 2.6 years. No significant difference was observed in the risk of bladder cancer (RRc: 0.99; 95% CI: 0.91–1.09).
Limits
- Classification errors are possible.
