Body Mass Index and Breast Cancer Risk: A Retrospective Multi-Institutional Analysis in Saudi Arabia

Background: The purpose of this study was to evaluate the association between the body mass index (BMI) of breast cancer patients and non-cancer females of the Eastern Province of Saudi Arabia. Methods: The weight, height and age was obtained from the patient records of 706 newly diagnosed breast cancer patients and of 20,872 non-cancer female patients who consulted the two largest hospitals in the Eastern Province of Saudi Arabia between 2006 and 2012. Factorial analysis of variance (ANOVA) was used to assess the association between the BMI, age and breast cancer status. Results: The mean BMI of the non-cancer females was 29.4 and the percentage of obese patients of the different age groups ranged from 23.9% to 66.5%. The BMI increased significantly with age. The ANOVA revealed that breast cancer patients older than 50 years had a significantly lower BMI compared to their non-cancer counterparts (p = 0.01). Conclusion: Our data confirm the high BMI of the Saudi Arabian female population. The reason for our finding of a lower BMI of postmenopausal breast cancer patients compared to their non-cancer counterparts is unclear. Future studies are warranted to assess the impact of possible confounding factors on the association between obesity and breast cancer risk. An interesting factor to investigate in future studies would particularly be the use of the anti-diabetic and cancer-protective drug metformin considering that diabetes mellitus is endemic in Saudi Arabia with a prevalence of 30%.