Metabolic comorbidities and the association with risks of recurrent metastatic disease in breast cancer survivors.

Background: Obesity and other metabolic comorbidities affect over 10% of patients with breast cancer and are closely related with adverse outcomes. Although metabolic comorbidities among breast cancer patients in low- and middle-income countries are suggested to be lower, only a few studies are currently available. Effective management of metabolic comorbidities in cancer patients has been associated with better outcomes.

Methods: Non-metastatic breast cancer patients (N = 1081) treated in our department (2014-2018) were monitored for the presence of high Body Mass Index (BMI), diabetes or glucose intolerance, dyslipidemia, and hypertension and the development of recurrent metastatic diseases during a median follow-up of 3.9 years.

Results: Glucose intolerance, hypertension, dyslipidemia, and BMI ≥ 27.7 kg/m considered at risk for metabolic comorbidities were found in 26.5, 42.6, 27.7, and 23.3% of breast cancer patients, respectively. Diabetes or glucose intolerance and having both glucose intolerance and dyslipidemia were associated with the risk of recurrent metastatic disease (OR = 1.442, 95%CI = 1.071-1.943, p = 0.016 and OR = 1.495, 95%CI = 1.090-2.049, p = 0.010; respectively). Having three or more metabolic comorbidities was significantly associated with the risk of recurrent metastatic disease (OR = 1.647, 95%CI = 1.139-2.382, p = 0.008) compared to patients without any comorbidity. The metabolic comorbidities were distributed unevenly among breast cancer subtypes. A significant association with recurrent metastatic disease was found in the Luminal B-like subtype. In post-menopausal patients, having more than three comorbidities was associated with a higher risk of recurrent metastatic disease compared to those without any comorbidity (OR = 2.000, 95%CI = 1.035-3.067, p = 0.001). The risks of having three or more metabolic comorbidities were significantly higher in breast cancer survivors who were obese, lived in an urban area, and received hormonal therapy of aromatase inhibitors.

Conclusion: Metabolic comorbidities were frequently found in breast cancer patients and were associated with higher risks to develop recurrent metastatic disease, particularly in post-menopausal women. Subsequent larger studies are needed to better understand the association of metabolic comorbidities with patients' quality of life and prognosis, and to explore the potential combination of clinical intervention and lifestyle modification in breast cancer survivors to treat as well as reduce their impact.