Metabolic Syndrome: does this influence breast cancer outcomes in the triple-negative population?

Metabolic syndrome (MS) is defined by having at least 3 of 4 components: obesity, dyslipidemia, hypertension (HTN), and diabetes. Prior studies analyzed the individual components of MS for all breast cancers which are predominantly hormone positive. Our study is the first to evaluate MS in triple-negative breast cancer (TNBC).

A retrospective review of TNBC from 2007 to 2013 identified 177 patients with complete information for statistical analysis. Cox proportional hazards models were used to test the association between MS, disease-free survival (DFS), and overall survival (OS).

48 (27%) patients had MS. After controlling for age, race, pathologic stage, surgery type, and additional comorbidities outside of MS, MS was significantly associated with poorer DFS (adjusted HR: 2.24, p = 0.030), but not associated with OS (adjusted HR: 1.92, p = 0.103). HTN was significantly associated with poorer DFS (adjusted HR: 3.63, p = 0.006) and OS (adjusted HR: 3.45, p = 0.035) in the univariable and multivariable analyses. Diabetes was not associated with worse OS or DFS. The 5-year age-adjusted OS rates for 60-year-old patients with and without diabetes were 85.8% and 87.3%, respectively. The age-adjusted 5-year OS rate for 60-year old patients was higher in patients with a body mass index (BMI) > 30 (90.2%) versus BMIs of 25-29.9 (88.2%) or < 25 (83.5%).

In the TNBC population, MS was significantly associated with poorer DFS, but not associated with OS. HTN was the only component of MS that was significantly associated with both DFS and OS. Obesity has a potential small protective benefit in the TNBC population.