P4-09-15: Clinical and Pathological Predictors of Outcome among Patients with Triple Negative Breast Cancer.

Abstract

Abstract Background Triple negative (TN) breast cancer portends a poor prognosis, yet outcomes remain heterogeneous. Specific characteristics of individual TN patients that can predict outcome compared to non-triple negative (NTN) patients have yet to be well defined. Methods: A prospective oncology database at Hackensack University Medical Center was queried for all patients with invasive breast cancer between 2000 and 2005. Patients with triple negative breast cancer were identified and compared to non-triple negative patients. Numerical values were compared by Mann-Whitney test; categorical values by Chi square/Fisher exact test. Log-rank test was used to compare outcome statistics, univariate and multivariate analyses were used to identify factors affecting relapse-free survival and overall survival. Results: A total of 2,216 patients were identified (TN: n=260; NTN: n=1956). There was no difference in race (white vs non-white; TN: 82.3% vs NTN: 87.3%) or family history of breast cancer (TN: 19.2% vs NTN: 16.8%). TN patients were significantly younger (median age; TN: 55.5 vs NTN 57.7; p< .05), had larger tumors (mean cm; TN: 3.1 vs NTN: 2.4; p<.05), had higher grade tumors (% grade 3; TN:74.6 vs NTN: 26.1; p<.0001), had higher proliferation index (>20% nuclei stained for Ki-67; TN: 30.8% vs NTN: 6.7%; p<.0001), but were less likely to have lymph node metastases at presentation (TN: 35.7% vs NTN: 48.0%; p < .0001). Among node negative patients, overall survival (OS) and disease free survival (DFS) were not significantly different between TN and NTN. Among node positive patients, both OS and DFS were worse for TN patients compared to NTN patients (p < .0008). By univariate analysis, age, nodal status, tumor size and tumor grade were all independent predictors of DFS, but proliferation rate and TN status were not. In a multivariate analysis, however, age, TN status, nodal status and tumor size were all significantly associated with DFS. Conclusion: Although TN patients have poor outcomes overall, among node negative patients, TN status does not affect overall nor disease free survival. Among node positive patients, however, TN status has a significant impact on outcome. In this analysis, well established predictors of outcome, including age, tumor size, tumor stage and nodal status were all independent predictors of outcome, but TN status and Ki-67 level were not. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-15.