Impact of body mass index, weight gain, and metabolic disorders on survival and prognosis in patients with breast cancer who underwent chemotherapy

BACKGROUND: Weight gain during chemotherapy in patients with breast cancer contributes to their poor prognosis. However, a growing number of studies have found that metabolic disorders seem to play a more important role in breast cancer prognosis than weight gain. This study aimed to explore the prognostic effects of body mass index (BMI), weight gain, and metabolic disorders on the overall survival (OS) and prognosis of patients with breast cancer who underwent chemotherapy. METHODS: Data from the inpatient medical records of patients with breast cancer who underwent chemotherapy at the Beijing Cancer Hospital Breast Cancer Center from January to December 2010 were retrospectively collected, and the patients were followed up until August 2020. RESULTS: A total of 438 patients with stages I to III breast cancer met the inclusion and exclusion criteria. Forty-nine (11.19%) patients died, while 82 (18.72%) patients had tumor recurrence and metastasis at the last follow-up (August 2020). From the time of diagnosis until after chemotherapy, no significant differences were observed in the body weight (t = 4.694, P < 0.001), BMI categories (χ(2) = 19.215, P = 0.001), and incidence of metabolic disorders (χ(2) = 24.841, P < 0.001); the BMI categories and weight change had no effect on the OS. Both univariate (χ(2) = 6.771, P = 0.009) and multivariate survival analyses (hazard ratio = 2.775, 95% confidence interval [CI]: 1.326–5.807, P = 0.007) showed that low high-density lipoprotein cholesterol (HDL-C) levels at diagnosis had a negative impact on the OS. The multivariate logistic regression analysis showed that the HDL-C level at diagnosis (odds ratio [OR] = 2.200, 95% CI: 0.996–4.859, P = 0.051) and metabolic disorders after chemotherapy (OR = 1.514, 95% CI: 1.047–2.189, P = 0.028) are risk factors for poor prognosis in patients with breast cancer. CONCLUSIONS: Chemotherapy led to weight gain and aggravated the metabolic disorders in patients with breast cancer. Low HDL-C levels at diagnosis and metabolic disorders after chemotherapy may have negative effects on the OS and prognosis of patients with breast cancer.