Survival Outcomes in Early HER2-Positive Breast Cancer: Focus on Body Mass Index
Posted: Tuesday, February 2, 2021
Weight loss of 5% or more after 2 years was associated with significantly worse outcomes in patients with HER2-positive breast cancer, and obesity was considered to be a good prognostic factor either, according to an exploratory analysis of the ALTTO BIG 2-06 trial. Evandro De Azambuja, MD, of the Camargo Cancer Center in Sao Paulo, Brazil, and colleagues published their results in JNCCN–Journal of the National Comprehensive Cancer Network.
“Weight loss during treatment and follow-up negatively impacts clinical outcomes,” the authors wrote. “Dietary counseling should be part of survivorship care programs.”
The retrospective study included 8,381 patients with HER2-positive early breast cancer from the randomized phase III ALTTO trial. Body mass index (BMI) was measured at randomization and 2 years later; patients were sorted into the following BMI categories: underweight (< 18.5 kg/m2), normal weight (18.5–25 kg/m2), overweight (25–30 kg/m2), and obese (> 30 kg/m2). Weight gain was defined as a weight change from baseline of at least +5%, and weight loss as a change of at least –5%.
Compared with a normal BMI, an obese BMI was associated with significantly worse overall survival (hazard ratio = 1.27) and distant disease–free survival (hazard ratio = 1.25), but it did not seem to impact disease-free survival. A weight loss of 5% or more after 2 years was associated with significantly worse overall survival (hazard ratio = 1.83), disease-free survival (hazard ratio = 1.34), and distant disease–free survival (hazard ratio = 1.46).
The study has a number of limitations. Primarily, the study used BMI, for which, according to the study authors, concerns have been raised about its ability to accurately reflect body fat distribution. In addition, the study could not determine why BMI was associated with worse overall survival and distant disease–free survival. Finally, the study was not a preplanned analysis, and 95% of patients were either White (69%) or Asian (26%).
Disclosure: For full disclosures of the study authors, visit jnccn.org.