Decreased serum HDL at initial diagnosis correlates with worse outcomes for triple-negative breast cancer but not non-TNBCs.

OBJECTIVE

This study aimed to evaluate the associations between metabolic syndrome (MS) and its components at initial diagnosis and outcomes of breast cancer including triple-negative breast cancer (TNBC) and non-TNBC.

METHODS

A cohort of 1,391 patients was reviewed between January 2004 and July 2008 (including 394 TNBC and 855 non-TNBC cases). MS and its components including body mass index (BMI), serum high-density lipoprotein (HDL) and triglycerides (TG) and their relationships with clinical outcomes were analyzed and then compared between groups.

RESULTS

The incidences of MS and its components including BMI, the levels of HDL and TG were not differently distributed between the 2 groups (all p's >0.05). However, more TNBC than non-TNBC patients presented with hypertension and elevated serum glucose (20.3% vs. 14.9% and 16.0% vs. 10.8%, p = 0.018 and p = 0.012, respectively). TNBC patients had poorer 5-year relapse-free survival (RFS) than non-TNBC patients (72.8% vs. 84.2%, p<0.0001). Only in the TNBC group, patients with low high-density lipoprotein (HDL) demonstrated worse RFS and overall survival (OS; p<0.0001). Multivariate analysis identified that low HDL was an independent worse prognostic factor for both RFS (hazard ratio [HR] = 3.266, 95% confidence interval [95%CI], 2.087-5.112, p<0.0001) and OS (HR = 3.071, 95%CI, 1.732-5.445, p<0.0001) in TNBC patients.

CONCLUSIONS

Decreased level of HDL may predict worse outcomes both in terms of RFS and OS for TNBC patients but not for non-TNBC patients. Further investigations are warranted to detect the underlying mechanisms.