Impact of post-diagnosis weight change on survival outcomes in Black and White breast cancer patients

Lihua Shang,Gini Fleming,Nora Jaskowiak,Dezheng Huo,Olufunmilayo I Olopade,Donald Hedeker,Masaya Hattori

doi:10.1186/s13058-021-01397-9

Abstract

PurposeTo evaluate weight change patterns over time following the diagnosis of breast cancer and to examine the association of post-diagnosis weight change and survival outcomes in Black and White patients.MethodsThe study included 2888 women diagnosed with non-metastatic breast cancer in 2000–2017 in Chicago. Longitudinal repeated measures of weight and height were collected, along with a questionnaire survey including questions on body size. Multilevel mixed-effects models were used to examine changes in body mass index (BMI). Delayed entry Cox proportional hazards models were used to investigate the impacts of changing slope of BMI on survival outcomes.ResultsAt diagnosis, most patients were overweight or obese with a mean BMI of 27.5 kg/m2 and 31.5 kg/m2 for Blacks and Whites, respectively. Notably, about 45% of the patients had cachexia before death and substantial weight loss started about 30 months before death. In multivariable-adjusted analyses, compared to stable weight, BMI loss (> 0.5 kg/m2/year) showed greater than 2-fold increased risk in overall survival (hazard ratio [HR] = 2.60, 95% CI 1.88–3.59), breast cancer-specific survival (HR = 3.05, 95% CI 1.91–4.86), and disease-free survival (HR = 2.12, 95% CI 1.52–2.96). The associations were not modified by race, age at diagnosis, and pre-diagnostic weight. BMI gain (> 0.5 kg/m2/year) was also related to worse survival, but the effect was weak (HR = 1.60, 95% CI 1.10–2.33 for overall survival).ConclusionBMI loss is a strong predictor of worse breast cancer outcomes. Growing prevalence of obesity may hide diagnosis of cancer cachexia, which can occur in a large proportion of breast cancer patients long before death.

Highlights

Obesity is a common health problem in the USA with its prevalence increasing in the past few decades [1]
In the stratified analysis of changing slope of body mass index (BMI) and survival outcomes, we found the U-shaped relationships were generally preserved for White and Black patients (Table 5): both weight gain and loss after diagnosis were associated with increased risk of the three outcomes
Using changing slope as a measure of weight loss was more powerful in risk prediction than change between two time points, reflecting more data being efficiently utilized. In this multiethnic cohort of breast cancer patients, we demonstrated a U-shaped relationship of weight change after diagnosis with all-cause mortality, breast cancerspecific mortality, and disease-free survival

Summary

Introduction

Obesity is a common health problem in the USA with its prevalence increasing in the past few decades [1]. Obesity is associated with an increased risk of many cancers [2], including postmenopausal breast cancer [3], but may impact cancer prognosis and treatment [4]. A recent meta-analysis reported that for a 5 kg/m2 increase in body mass index (BMI) before diagnosis, overall mortality and breast cancer mortality risk increased by 17% and 18%, respectively [5]. Several studies found an association of weight loss with increased risk of mortality [6,7,8,9,10,11]. While some studies found an association of weight gain with increased risk of mortality [6, 8, 9, 12], other studies did not find an association between weight gain and survival [10, 11]

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Conclusion