Abstract
Introduction: Cancer and diabetes are increasingly prevalent, and it is not unusual for an individual to have both at the same time, given both are common and that one can increase the risk of the other. The occurrence of cancer among those with diabetes has significant ramifications to the person, the clinical team providing their care and the broader health system.
Methods: For the period 2006–2019, we used national-level diabetes (Virtual Diabetes Register) and cancer (New Zealand Cancer Registry) data on nearly 5 million individuals over 44 million person-years of follow-up. We used cancer incidence among those with and without prevalent diabetes to project cancer incidence across the 2020–2044 period, using age-period-cohort modelling to account for factors driving trends in cancer incidence.
Results: Cancer rates were highest among those with diabetes for 21 of the 24 most common cancers. The greatest differences in cancer incidence by diabetes status were in uterine, liver, pancreatic and kidney cancers, which all have a strong relationship with obesity. In terms of projected burden, cancers in people with diabetes were projected to more than double from 20,243 to 48,773, a 141% increase from 2015–2019 to 2040–2044. Age-standardised cancer incidence was projected to increase 2.4 times faster for people with diabetes (annual relative increase of 0.4% vs 0.2% for those without diabetes).
Conclusions: Our findings reinforce the fact that diabetes prevention activities are also cancer prevention activities and must therefore be prioritised and resourced in tandem.