A new meta-analysis indicated that people with diabetes are not only at an increased risk of developing breast and colon cancer, but are also at an increased risk of dying from the diseases.
The results of the meta-analysis were presented by Kirstin De Bruijn, a PhD student at Erasmus University Medical Center, Rotterdam, the Netherlands, at the 2013 European Cancer Congress.
“Our meta-analysis is the first to combine incidence and death from breast and colon cancer, while excluding all other causes of death,” De Bruijn said in a press release. “We have investigated the link between diabetes and the risk of developing as well as the risk of dying from these cancers.”
De Bruijn and colleagues looked at the results from 20 studies published after 2007 that included data to allow researchers to extract or calculate hazard ratios (HRs) for the relationship between diabetes and breast and colorectal cancer incidence and cancer-specific mortality. The 20 studies included information on more than 1.9 million patients with cancer and with or without diabetes.
Data indicated that patients with diabetes had a 23% increased risk for developing breast cancer (HR = 1.23; 95% CI, 1.12–1.34) and a 26% increased risk for developing colorectal cancer (HR = 1.26; 95% CI, 1.14–1.40) compared with patients without diabetes.
Excluding all other causes of death, patients with diabetes also had a 38% increased risk of dying from breast cancer (HR = 1.38; 95% CI, 1.20–1.58) and a 30% increased risk of dying from colorectal cancer (HR = 1.30; 95% CI, 1.15–1.47) compared with patients without diabetes.
“Cancer patients who are obese and diabetic are an already more vulnerable group of individuals when it comes to surgery, as they have an increased risk of developing complications both during and after surgery,” De Bruijn said in a press release. “If more obese and diabetic patients have to have an operation because of cancer, healthcare costs will increase.”
De Bruijn and colleagues recommended increased efforts to raise awareness of these risks and prevention campaigns designed to highlight the link between obesity, diabetes, and cancer risk.
“For further research, it would be important to study how other, competing risk factors might affect survival, as elderly cancer patients with diabetes are usually diagnosed with other conditions as well,” commented ECCO President Cornelis van de Velde. “Additionally, the potential role of metformin in relation to improved survival and cancer recurrence needs to be studied.”