Prognostic Value of Triple-Negative Phenotype at the Time of Locally Recurrent, Conservatively Treated Breast Cancer

Purpose: To evaluate the prognostic value of triple-negative (TN) ER, PR, Her2/neu basal-like carcinoma of the breast, at the time of ipsilateral breast tumor recurrence (IBTR) after conservative surgery and radiation treatment (RT). Methods and Materials: A tissue microarray was constructed of 47 IBTR specimens of patients who experienced an IBTR after conservative surgery and RT that were processed and stained for ER, PR, and HER2/neu. Results: At a median post-recurrence follow-up of 7.5 years, the 5-year overall survival (OS) and disease metastasis-free survival (DMFS) after IBTR were 91.4% and 83.0%, respectively. Median time to tumor recurrence (TTR) and IBTR was shorter in the TN phenotype (3.88 vs. 5.00 years; p = 0.09). The TN tumors were not associated with size of local recurrence or recurrence elsewhere in the breast. Despite administration of standard chemotherapy at the time of IBTR, the 5-year DMFS and 5-year OS for the TN cohort were 48.6% and 72.7%, respectively. The 5-year DMFS was 48.6% for TN tumors and 90.8% for non-TN tumors (p < 0.01). By univariate analysis, significant factors associated with poor 5-year DMFS and OS after IBTR included: TN phenotype (p < 0.01), TTR 3 years or less (p < 0.01), local recurrence at or near the original tumor site (p = 0.08). In multivariate analysis, TN was a significant independent predictor of poorer 5-year DMFS (relative risk, 5.91; 95% confidence interval, 1.83-19.01; p < 0.01) after IBTR. Conclusions: Although patients experiencing an IBTR have a relatively favorable prognosis, those with IBTR events of the TN phenotype had a rather poor prognosis despite receiving standard chemotherapy. Strategies with novel systemic therapies to improve outcomes in patients experiencing IBTR of the TN phenotype are warranted.