Pfeiler G.,Medical University of Vienna |
Stoger H.,Medical University of Graz |
Dubsky P.,Medical University of Vienna |
Mlineritsch B.,University of Salzburg |
And 17 more authors.
British Journal of Cancer | Year: 2013
Background:There exists evidence that body mass index (BMI) impacts on the efficacy of aromatase inhibitors in patients with breast cancer. The relationship between BMI and the efficacy of tamoxifen is conflicting. We investigated the impact of BMI on the efficacy of single tamoxifen and tamoxifen plus an aromatase inhibitor in the well-defined prospective study population of the ABCSG-06 trial.Methods:ABCSG-06 investigated the efficacy of tamoxifen vs tamoxifen plus aminoglutethimide in postmenopausal women with hormone receptor-positive breast cancer. Taking BMI at baseline, patients were classified as normal weight (BMI=18.5-24.9 kg m-2), overweight (BMI=25-29.9 kg m-2), and obese (30 kg m-2) according to WHO criteria.Results:Overweight+obese patients had an increased risk for distant recurrences (hazard ratio (HR): 1.51; Cox P=0·018) and a worse overall survival (OS; HR: 1·49; Cox P=0·052) compared with normal weight patients. Analysing patients treated with single tamoxifen only, no difference between overweight+obese patients and normal weight patients regarding distant recurrence-free survival (HR: 1.35; Cox P=0·24) and OS (HR: 0.99; Cox P=0·97) could be observed. In contrast, in the group of patients treated with the combination of tamoxifen plus aminoglutethimide, overweight+obese patients had an increased risk for distant recurrences (1.67; Cox P=0·03) and a worse OS (1.47; Cox P=0·11) compared with normal weight patients.Conclusion:BMI impacts on the efficacy of aromatase inhibitor-based treatment but not single tamoxifen. © 2013 Cancer Research UK. All rights reserved.