Cancer and diabetes co-occurrence: A national study with 44 million person-years of follow-up

Abstract

The number of new cases of cancer is increasing each year, and rates of diabetes mellitus are also increasing dramatically over time. It is not an unusual occurrence for an individual to have both cancer and diabetes at the same time, given they are both individually common, and that one condition can increase the risk of the other. In this manuscript, we use national-level diabetes (Virtual Diabetes Register) and cancer (New Zealand Cancer Registry) data on nearly five million individuals over 44 million person-years of follow-up to examine the occurrence of cancer amongst a national prevalent cohort of patients with diabetes. We completed this analysis separately by cancer for the 24 most commonly diagnosed cancers in Aotearoa New Zealand, and then compared the occurrence of cancer among those with diabetes to those without diabetes. We found that the rate of cancer was highest amongst those with diabetes for 21 of the 24 most common cancers diagnosed over our study period, with excess risk among those with diabetes ranging between 11% (non-Hodgkin’s lymphoma) and 236% (liver cancer). The cancers with the greatest difference in incidence between those with diabetes and those without diabetes tended to be within the endocrine or gastrointestinal system, and/or had a strong relationship with obesity. However, in an absolute sense, due to the volume of breast, colorectal and lung cancers, prevention of the more modest excess cancer risk among those with diabetes (16%, 22% and 48%, respectively) would lead to a substantial overall reduction in the total burden of cancer in the population. Our findings reinforce the fact that diabetes prevention activities are also cancer prevention activities, and must therefore be prioritised and resourced in tandem.

Does diabetes affect breast cancer survival?

“…Diabetes is a multisystem disorder that is associated with a greater risk of getting breast cancer 7–10 . In Aotearoa/New Zealand, the rate of breast cancer is approximately 15% higher among those with diabetes than people without diabetes 10 . Patients with diabetes often have worse tumor characteristics at cancer diagnosis, and poorer outcomes when compared to patients without diabetes 11,12 .…”

“…Diabetes is a multisystem disorder that is associated with a greater risk of getting breast cancer 7–10 . In Aotearoa/New Zealand, the rate of breast cancer is approximately 15% higher among those with diabetes than people without diabetes 10 .…”

Effects of Metformin on Risk and Prognosis of Biliary Tract Cancer: A Systematic Review and Meta-Analysis

“…Compared to non-diabetic individuals, patients with type 2 diabetes have an increased risk and worse prognosis for BTC [ 10 , 11 , 12 ]. Recent studies have also found that the prevalence and co-occurrence of diabetes is higher in digestive cancers [ 13 , 14 ]. Metformin is often used as the first-line treatment for type 2 diabetes [ 15 ].…”

Bidirectional Mendelian randomization study of insulin-related traits and risk of ovarian cancer

“…Many studies and observations in the field of overseas studies have confirmed this view. It is reported that among patients with type 2 diabetes, the relative risk of endometrial cancer, liver cancer and pancreatic cancer is more than 2 times, while the relative risk of bladder cancer, breast cancer and colorectal cancer is as high as 1.5 times (9)(10)(11)(12). In addition to the increase in incidence rate, the overall mortality rate of diabetes patients when diagnosed with cancer is higher (13) than that of the non-disease group.…”