Background: Diabetes and cancer are public health issues worldwide; studies have shown that diabetes is related to increased breast cancer mortality. The purpose of this study was to examine associations between HbA1C and obesity with tumor stage and mortality among breast cancer patients.
Methods: Data for 82 patients with breast cancer (36-89 years of age, diagnosed /treated 1999-2009) were provided by the University of Arkansas for Medical Sciences (UAMS) Data Trust Warehouse. Survival time was estimated from start date of service to date of last follow-up or date of death. The Kaplan-Meier method provided analysis of survival curves for two groups of HbA1C (HbA1C < 6.5% vs HbA1C ≥ 6.5%) and two groups of BMI (BMI < 30 vs BMI ≥ 30 kg/m2); survival curves were compared using log-rank tests. Associations between HbA1C and BMI, and between HbA1C and tumor stage were determined by chi-square.
Results: The relationship between tumor stages and HbA1C was not statistically significant (X2 = 0.093, p = 0.47, df = 1). The relationship between obesity and HbA1C was statistically significant (X2 = 6.13, p = 0.013, df = 1). Log-rank tests did not show statistically significant differences between survival curves (HbA1C curves, p = 0.4; Obesity curves, p = 0.09).
Conclusion: While there was a statistically significant association between HbA1C and obesity, there were no significant associations found with this analysis. However, there are clinically meaningful relationships based on observed trends. Future directions for research may involve exploring a larger sample of patients and the role of therapeutic regimens on blood sugar control and BMI of breast cancer patients and influence on cancer prognosis.
Keywords: Breast cancer; Diabetes; HbA1C; Obesity; Tumor stage.