Israel Medical Association Journal

The increasing use of computerized medical records has made the clinical data of the entire population available for epidemiological research. The resultant accessibility to this information mandates careful adaptions of ethical guidelines regarding the handling of clinical data. At the same time it grants a unique opportunity to explore the clinical nature of health and disease in large populations across all of society’s strata, socioeconomic levels, ethnicities, and geographic locations regardless of their vicinity or distance to tertiary care centers. Analysis of large databases allows us to learn the public‘s behavior towards medical services and to investigate how medical interventions affect outcomes over time. Moreover, interaction between different co-morbidities can also be better understood by large population studies. The huge numbers of patients involved in these studies provide a good model of multivariate analysis, a statistical tool that by following proper population adjustments underlines the true independent associations between different conditions. Nevertheless, the limitations of these studies should be borne in mind, such as in-built imprecision of diagnoses, incompleteness of the medical data, and the fact that these databases were initially planned for clinical and not investigational use. 

Objectives: To compare the incidence rate of overall and site-specific cancers among Israeli Arabs with T2DM to that of Israeli Arabs without.

Methods: A retrospective cohort study of all adult Arab members of Clalit Healthcare Services in northern Israel was conducted over a 10 year period (1999–2008).

Results: During the study period 752 and 2045 incident cases of cancer were diagnosed among 13,450 adults with diabetes and 74,484 without, respectively. The follow-up time involved 817,506 person-years. Diabetes was associated with a standard incidence ratio (SIR) of 3.27 (95%CI 1.49–5.05) and 2.87 (95%CI 1.25–4.50) for pancreatic cancer in men and women, respectively. A significantly reduced SIR (0.67, 95%CI 0.36–0.99) was observed for esophageal, stomach and intestinal cancers in men.

Conclusions: Our findings support an association between T2DM and increased risk of cancer of the pancreas in Arab men and women. A significantly reduced risk of all other cancers was observed only in Arab men. Our findings underscore the need for effective diabetes and cancer prevention and intervention programs.