oa Body Size, Physical Activity And Risk Of Cancers Of The Breast, Prostate And Colorectum Among Diabetic Patients

ABSTRACT Introduction Over the last 30 years the incidences of cancer and diabetes have been increasing progressively and there is both epidemiologic and experimental data linking diabetes and various cancer outcomes. Previous studies has shown that physical activity, height, and obesity; measured by weight, waist circumference, waist-to-hip ratio and body mass index were associated with the risk of diabetes and common cancer outcomes such as breast, colorectal and prostate cancer. However, there is little data on whether these modifiable risk factors are predictive of these malignancies among diabetics. The identification of factors that modify the risk of cancer among diabetics could lead to better surveillance or intervention to reduce cancer incidence among those at highest risk. Aim The aim of this study was to observe the relationship between anthropometric measures, including weight, height, and adiposity and physical activity with the risk of breast, colorectal and prostate cancer among diabetic individuals within the European Prospective Investigation into Cancer and Nutrition cohort. Methods Data from 27,365 diabetics from nine European countries between the ages of 20 to 85 years and a mean follow-up of 11.1 years from the European Prospective Investigation into Cancer and Nutrition (EPIC) was used. Of the 27,365 diabetics, 546 developed breast cancer, 363 developed prostate cancer and 308 developed colorectal cancer. Hazard ratios (HR) and 95% confidence interval (CI) were estimated using a Cox proportional hazard model, stratified by age in one year increments, gender and centre and adjusted for smoking status, alcohol consumption, education, BMI and physical activity. The HR was used to examine the association between anthropometric measures at recruitment and PA estimated from questionnaires with breast, prostate and colorectal cancer. Results There were no significant associations between height, weight, waist circumference waist-to-hip ratio, BMI and physical activity with breast, prostate and colorectal cancer when comparing the highest and lowest quartiles. However, there was a significant association between height and breast cancer when comparing the third quartile to the first (Q3 vs Q1, HR: 3.34, 95%CI: 1.09-10.22). Moreover, there was a suggestive inverse association between physical activity with breast and prostate cancer (P-trend 0.085 and P-trend 0.07, respectively). There was also a suggestive positive association between abdominal obesity and colorectal cancer (P-trend 0.04 for waist circumference and P-trend 0.08 for waist-to-hip ratio). Conclusion In this study of diabetic patients nested within the EPIC cohort, there was little evidence for an association between anthropometric measures and physical activity with breast, prostate and colorectal cancer. However, there was a suggestive association between physical activity with breast and prostate cancer and a suggestive association between abdominal obesity and colorectal cancer. Due to the limited number of cases in this study, further investigations between the associations of these modifiable factors with these cancers among diabetics are required.