Bendix Carstensen

Diabetes and cancer (1): evaluating the temporal relationship between type 2 diabetes and cancer incidence

Substantial evidence suggests that people with type 2 diabetes have an increased risk of developing several types of cancers. These associations may be due to a number of direct and indirect mechanisms. Observational studies of these associations, including the potential role for glucose-lowering therapy, are being increasingly reported, but face a number of methodological challenges. This paper is the first of two review papers addressing methodological aspects underpinning the interpretations of links between diabetes and cancer, and suggests potential approaches to study designs to be considered in observational studies. This paper reviews factors related to cancer incidence in the diabetic population; the second paper relates to studies of cancer mortality.

Mortality after cancer among patients with diabetes mellitus: effect of diabetes duration and treatment: (questionable) classification of diabetic patients based on combination of specific glucose-lowering drugs. Reply to Holden SE, Bannister CA, Currie CJ [letter]

To the Editor: In the light of the general comments made about our article [1] by Holden et al [2], we acknowledge that we did not specify with sufficient emphasis that our study was based on the entire population of cancer patients in Denmark, that is to say, it was essentially demographic in its nature. The uncertainty about the underlying study base has led Holden et al to raise concerns about the lack of characterisation of the cohorts. Unlike clinical observational studies of patients from clinical databases, there is only limited clinical information on the general population of all cancer patients in Denmark, and hence it is not possible to provide a detailed clinical characterisation of the population. On the other hand, our study gives an overall picture of how the entire population of cancer patients fare in relation to their diabetes status. The following are our replies to the specific questions raised by Holden et al: