Obesity Has Paradoxical Effect on Early Versus Advanced Breast Cancer
April 30, 2021

Researchers have uncovered an obesity paradox in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer.

Clinical data revealed that an obese or overweight pretreatment body mass index (BMI) was associated with worse outcomes in HER2-positive early breast cancer, but improved survival outcomes in HER2-positive advanced breast cancer.

For the study, published in npj Breast Cancer, Natansh D. Modi, Flinders University, Adelaide, Australia, and colleagues evaluated data from 5,099 patients with early breast cancer and 3,496 patients with advanced breast cancer to determine associations between BMI and survival rates across both stages.

In the early breast cancer cohort, higher BMI was associated with worse overall survival (OS) (hazard ratio [HR] overweight = 1.30; 95% confidence interval [CI], 1.13-1.51; HR obese = 1.37; 95% CI, 1.14-1.64; P = P = .061).

Conversely, in the advanced breast cancer cohort, higher BMI was significantly associated with improved OS (HR overweight = 0.85; 95% CI, 0.76-0.96; HR obese = 0.82; 95% CI, 0.72-0.95; P = .014), and progression-free survival (HR overweight = 0.91; 95% CI, 0.83-1.01; HR obese = 0.87; 95% CI, 0.77-0.98; P = .034).

“This is world-first evidence of an obesity paradox in breast cancer and highlights an urgent need to understand the biological basis of obesity impacts throughout breast cancer diagnosis and treatment,” concluded Ashley Hopkins, PhD, Flinders University.

Reference: http://dx.doi.org/10.1038/s41523-021-00241-9

SOURCE: Flinders University