Good glucose control in people with obesity and type 2 diabetes can reduce the risk of developing cancer by up to 60%, according to a study published in the journal Diabetes Care.

While it is well-known that losing weight can prevent cancer in those with type 2 diabetes, there have been relatively few studies on the association between weight loss, risk of cancer and glucose control in patients with both obesity and type 2 diabetes.

The largest difference was observed when patients achieved normal glucose control

The researchers studied a group of 393 people with type 2 diabetes and underwent bariatric surgery, and compared them with a control group of 308 people with type 2 diabetes and severe obesity who had not undergone bariatric surgery.

In the surgery group, 68 individuals (17%) developed cancer in parallel with a significant weight loss. In the control group, 74 (24%) individuals developed cancer; these individuals retained their condition of severe obesity over the median follow-up period of 21 years. Overall, the risk of getting cancer was 37% lower in the group that underwent obesity surgery.

However, the largest difference was observed when cancer risk was analysed in the patients who achieved normal glucose control and had no relapse of diabetes over a 10-year period. Among these patients, the incidence of cancer was 12 out of 102 (12%), compared to 75 out of 335 (22%) in the group whose diabetes had recurred in the same period. Thus, the results show a 60% reduction in cancer risk in the group where normal glucose control was maintained over 10 years.

The results provide “vital guidance” for prevention of cancer

Co-author Kajsa Sjöholm, Associate Professor of Molecular Medicine at Sahlgrenska Academy, University of Gothenburg, said: “What we see is that, among patients with type 2 diabetes, many cancer cases are preventable. These results are an important contribution that enhances our understanding of the connection between glucose control and cancer prevention.”

Magdalena Taube, Associate Professor of Molecular Medicine at Sahlgrenska Academy, University of Gothenburg, lead author of the study, said the results provide “vital guidance for prevention of cancer in patients with obesity and type 2 diabetes.”