

1. Consultant Radiation Oncology, Chairman of Radiation Protection Unit, Director of Breast Cancer Research Chair, King Khalid University Hospital, Riyadh, Saudi Arabia.
2. Associate Professor, King Saud University, Riyadh, Saudi Arabia.
3. Medical Student, King Khalid University Hospital, Riyadh, Saudi Arabia.
5. Associate Professor, Radiation Oncology, NCI, Cairo University, Cairo, Egypt.
Background: Obesity and increased body mass index (BMI) are increasing among Saudi women across the all age groups, with an overall prevalence of 44%. Increased BMI is associated with advanced stage breast cancer and dismal survival; however impact of BMI on locoregional control (LRC) is less studied. We aimed to evaluate the impact of BMI on LRC in Saudi patients with breast cancer after breast conserving surgery (BCS) and modified radical mastectomy (MRM).
Materials and methods: Between February 1988 and August 2008, 112 patients with breast cancer were treated with BCS and MRM followed by adjuvant chemotherapy and radiotherapy. Median age was 47.01 years (23-76). Mean BMI was 38.1 kg/m2 (15.7-52.8); BMI 18.5-25 kg/m2 (normal weight) in 20 (17.8%), BMI 26-30 kg/m2 (overweight) in 32 (28.6%), BMI 31-40 kg/m2 (obese) in 48 (42.9%) and BMI > 40 kg/m2 (morbid obese) in 12 (10.7%). Median follow up period was 9 years (5-17). Cox proportional hazard analysis was done using SPSS 19.0.
Results: Total ten locoregional recurrences (8.93%) were seen. The 5 and 10 years LRC were 86.4% and 86.4% respectively. Multivariate analysis showed poor LRC in BMI 26-30 kg/m2 (HR: 3.4; 95% CI.3.0-3.8, p 0.01). Others factors associated with poor LRC were; age less than 40 years, premenopausal status, and no adjuvant radiotherapy, and T4, N2 and N3 stages.
Conclusion: Overweight and obese patients had better locoregional control in our study, however further larger trials are warranted.
Keywords: Body mass index, breast cancer, breast conserving surgery, modified radical mastectomy