Impact of diabetes and hyperglycemia on outcomes in advanced breast cancer patients.

Abstract

e12027 Background: Clinical experience and previous studies suggest that women with diabetes and breast cancer (BrCa) have worse outcomes than their non-diabetic counterparts. However, analysis of the contribution of diabetes to BrCa specific mortality is difficult because of the substantial mortality attributed to diabetes alone and because diabetes is commonly associated with adverse prognostic factors specific to BrCa. The purpose of this study was to examine the impact of diabetes and hyperglycemia on cancer-specific survival of patients with metastatic or recurrent BrCa. Methods: We performed a retrospective analysis of patients with advanced BrCa receiving palliative chemotherapy from 2006 to 2011 at the National Cancer Institute in Mexico, and compared breast cancer-specific mortality in diabetic and non-diabetic patients, as well as in patients that presented hyperglycemia during palliative treatment. Results: A total of 265 patients receiving palliative therapy were eligible for inclusion. Previous diagnosis or detection of diabetes at recurrence was recorded in 40 patients (15%). No difference was observed between diabetic and non-diabetic patients in terms of overall survival (OS). A statistically significant difference in OS was observed between patients without diabetes and diabetics who had hyperglycemia (p=0.003). OS in diabetic patients with proper metabolic control was shown to be superior compared to diabetics with hyperglycemia (p=0.01). Hyperglycemia was identified in 14% of non-diabetics at some point while receiving palliative treatment. For patients that experienced hyperglycemia during treatment or who had a mean glucose level > 130, either in the diabetic or non-diabetic subgroups, a worse outcome was noted compared to normoglycemic patients, with a HR of 1.5 (p=0.029) and HR of 2.04 (p=0.006) for death, respectively. Conclusions: Elevated glucose levels confer a poor outcome in diabetic and non-diabetic patients in contrast with patients with normoglycemic levels, conferring an elevated risk of death. According to these results, clinicians must monitor glucose levels during treatment for advanced BrCa disease, and should take action in order to maintain normal glucose levels.