Distinct outcomes in patients with different molecular subtypes of inflammatory breast cancer

OBJECTIVES: To determine the outcome of patients with luminal A, luminal B, human epidermal growth factor receptor-2 (HER-2) positive, and triple negative molecular subtypes of inflammatory breast cancer (IBC) using a retrospective analysis.

METHODS: This study was conducted between February 2004 and February 2010 in 3 different hospitals in China. The clinical outcomes, pathological features, and treatment strategies were analyzed in 67 cases of IBC without distant metastases. A chi-square test and one-way ANOVA were used to assess outcomes between different subtypes. Overall survival (OS) was analyzed using the Kaplan-Meier method and multivariate analysis was conducted using the Cox regression model.

RESULTS: The 2-year OS rate was 55% for the entire cohort. Median OS time among patients with luminal A was 35 months, luminal B was 30 months, HER-2 positive was 24 months, and triple negative subtypes was 20 months, and were significantly different from each other (p=0.001). Using multivariate analysis, luminal A had 76% (p=0.037), luminal B had 54% (p=0.048), and HER-2 positive subtypes had 47% (p=0.032) decreased risk of death compared with the triple negative subtype. Furthermore, elevated Ki-67 labeling was associated with increased risk of death, while the surgical treatment significantly improved patient survival.

CONCLUSION: Breast cancer subtypes are associated with distinct outcomes in IBC patients. Patients that presented with triple negative IBC had poorer outcome than luminal A, luminal B, and HER-2 subtypes. These results indicate that IBC is a heterogeneous disease similar to the conventional breast cancer.