Triple negative breast cancer confers higher recurrence rates after breast conserving therapy.

Abstract

Abstract Abstract #5127 Purpose
 There has been a recent surge of information regarding the treatment outcomes for women with estrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative breast cancer; known as the triple negative (TN) subtype. The purpose of this study is to evaluate the impact of these receptor expressions on local, regional and distant recurrences, and overall survival (OS) in patients undergoing breast conserving therapy (BCT).
 Patients and Methods
 The study population included 475 primary invasive female breast cancer patients (excluding Stage IV); who were residents of Fulton-Dekalb counties in Atlanta when diagnosed in 2003-2004 and treated within the Emory University affiliated hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.4 years. The endpoints of the study were local, regional and distant recurrences, and OS. Tumors were subgrouped as: ER-/PR-/HER2- (TN), ER+/PR+/HER2-, ER+/PR+/HER2+, ER+/PR+/HER2-. Chi-square and Fisher exact tests were employed.
 Results
 For the entire population, median age was 58 years. TN tumors accounted for 17% of the cases. Of the TN patients, 78% were African-American (p<0.01) and 40% had BCT. The majority of TN tumors were high grade (71%), p< 0.01. Total recurrence was 33% among the TN patients vs. 14% in the combined non-TN patient group, p< 0.01. Death occurred among 29% of TN vs. 14% of non-TN, p< 0.01.
 For the patients that were treated with BCT, 94% of TN patients completed their adjuvant radiation therapy and 73% received chemotherapy. Of those receiving BCT, recurrence was 28% for TN patients and 6% for non-TN patients (p<0.01). Local recurrence was 9% and 4% for TN and non-TN patients, respectively and distant metastatic rate was 16% versus 2% respectively (p< 0.01). There were no regional recurrences in the BCT group. Time to recurrence, OS, time to death, and breast cancer specific death did not differ between the two groups.
 Conclusion
 A significant increase in local recurrence and distant metastatic rates were observed after BCT among patients diagnosed with TN breast cancers; however there was not a significant short-term survival difference between the TN and non-TN receptor groups. The complexity of this patient population within the conventional treatment algorithm warrants further investigation to reduce local and distant recurrences. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5127.