Effects of Weight Loss on Breast Cancer OutcomesApr 6, 2021
Research of BMI data in patients with HER2-positive early breast cancer has shown 5% weight loss in patients over two years to be associated with worse outcomes while weight gain over the same time period did not affect survival rates.
The BMI data came from the ALTTO BIG 2-06 trial, which collected height and weight data in 8,381 patients with HER2-positive early breast cancer treated with chemotherapy plus trastuzumab and/or lapatinib. At the start of treatment, 2.2% of patients were underweight, 45.3% were normal weight, 32.1% were classified as overweight, and 20.4% were obese (defined as a BMI greater than 30). Initial obesity was associated with worse outcomes, including more frequent and serious adverse events leading to treatment discontinuation, as well as significantly worse overall survival rates.
“It was surprising to see that more than 5% weight loss at 2 years was associated with poorer distant disease–free survival. Is our general advice to obese/overweight patient to exercise and lose weight wrong?” said Anthony D. Elias, MD. According to Dr. Elias, careful examination of the Kaplan-Meier hazard plots suggests that the relapse curves for those with weight loss are steeper in the second and third years of follow-up, but thereafter are relatively parallel, meaning that weight loss observed early may be an indication for impending relapse of breast cancer.
The study highlights the importance of weight management in cancer survivorship and aims to provide the basis for further research and oncology trials to guide weight control during the survivorship period.