Role of obesity in a randomized placebo-controlled trial of difluoromethylornithine (DFMO) + sulindac for the prevention of sporadic colorectal adenomas
Chemoprevention with the polyamine-inhibitory regimen difluoromethylornithine (DFMO) + sulindac markedly reduces risk of recurrent adenoma in colorectal adenoma patients. Obesity is associated with risk of colorectal adenoma and colorectal cancer. This study investigates how obesity influences risk of recurrent adenoma after prolonged treatment with DFMO + sulindac versus placebo.
Our analysis included subjects enrolled in the phase III colorectal adenoma prevention clinical trial investigating DFMO + sulindac versus placebo. Patients were classified by obesity (body mass index, BMI ≥ 30 kg/m2) status at baseline. Pearson χ2 statistic and Mann–Whitney U test were used to compare baseline characteristics, including rectal tissue polyamine levels. Log-binomial regression analysis was used to determine the risk ratio (RR) of recurrent adenomas, adjusted for covariates and an interaction term for obesity and treatment.
The final analytic cohort was comprised of 267 patients. In separate regression models, the risk of adenoma recurrence after treatment compared to placebo was similar for obese (RR = 0.32, 95 % CI 15–71) and non-obese patients (RR = 0.27, 95 % CI 15–49). No significant interaction was detected between obesity, treatment, and risk of colorectal adenoma in the full regression model (p interaction = 0.91).
Obesity does not substantially modify the colorectal adenoma risk reduction ascribed to DFMO + sulindac versus placebo.
- Role of obesity in a randomized placebo-controlled trial of difluoromethylornithine (DFMO) + sulindac for the prevention of sporadic colorectal adenomas
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Cancer Causes & Control
Volume 23, Issue 10 , pp 1739-1744
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- Springer Netherlands
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- Body mass index
- Colorectal adenoma
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- Author Affiliations
- 1. Chao Family Comprehensive Cancer Center, University of California, Irvine, CA, 92697, USA
- 2. Division of Hematology/Oncology, Department of Medicine, University of California, Irvine, CA, 92697, USA
- 3. Department of Epidemiology, University of California, Irvine, CA, 92697, USA
- 8. Division of Hematology/Oncology, University of California Irvine Medical Center, 101 The City Drive South, Orange, CA, 92868, USA
- 4. Division of Human Genetics and Metabolism, Department of Pediatrics, University of California, Irvine, CA, 92697, USA
- 5. Department of Cell Biology and Anatomy, College of Medicine, Tucson, AZ, 85724, USA
- 6. Gastrointestinal Cancer Program, Arizona Cancer Center, Tucson, AZ, 85724, USA
- 7. Department of Biological Sciences, University of California, Irvine, CA, 92697, USA