The Breast: VOLUME 55, P16-24, FEBRUARY
01, 2021
Highlights
•This is the first large multicenter cohort reporting BMI’s
effect on outcomes among patients with metastatic breast cancer.
•Overweight or obese status does not negatively influence
outcome of metastatic breast cancer patients, whatever the subtype.
•Underweight is a strong negative independent prognostic
factor on outcomes, whatever the subtype.
Background
High Body mass index (BMI) is a risk factor for breast
cancer among postmenopausal women and an adverse prognostic factor in
early-stage. Little is known about its impact on clinical outcomes in patients
with metastatic breast cancer (MBC).
Methods
The National ESME-MBC observational cohort includes all
consecutive patients newly diagnosed with MBC between Jan 2008 and Dec 2016 in
the 18 French comprehensive cancer centers.
Results
Of 22 463 patients in ESME-MBC, 12 999 women had
BMI data available at MBC diagnosis. Median BMI was 24.9 kg/m2 (range
12.1–66.5); 20% of women were obese and 5% underweight. Obesity was associated
with more de novo MBC, while underweight patients had more aggressive
cancer features. Median overall survival (OS) of the BMI cohort was 47.4 months
(95% CI [46.2–48.5]) (median follow-up: 48.6 months). Underweight was
independently associated with a worse OS (median OS 33 months; HR 1.14, 95%CI,
1.02–1.27) and first line progression-free survival (HR, 1.11; 95%CI, 1.01;
1.22), while overweight or obesity had no effect.
Conclusion
Overweight and obesity are not associated with poorer
outcomes in women with metastatic disease, while underweight appears as an
independent adverse prognostic factor.
