Predictive factors and patterns of recurrence in patients with triple negative breast cancer.

Background: We investigated the outcomes of patients with triple negative breast cancer ([TNBC] = estrogen receptor negative, progesterone receptor negative, and HER2 nonamplified).

Methods: We identified 414 patients with stage I-III TNBC treated between 1999 and 2008. Data included patient/tumor characteristics, surgical, systemic, and radiation treatment received, and breast cancer-specific survival. Data were compared using Chi square, Fisher exact test, and logistic regression. A p value <.05 was considered significant.

Results: The cohort included 414 patients (mean age 53.8 ± 12.5 years) with a mean follow-up of 68.2 ± 36.4 months. Of 414 patients, 304 (73.4 %) had no evidence of recurrence, while 110 (26.6 %) had recurrent disease, including 19 (17.3 %) with isolated locoregional recurrence, 70 (63.6 %) with isolated distant recurrence, and 21 (19.1 %) with both. Of 91 patients with distant recurrences, lung was most common (n = 38), followed by brain (n = 32), bone (n = 31), and liver (n = 29). Factors significantly associated with recurrence included increasing tumor size, positive nodal status, increasing stage, and type of chemotherapy (adjuvant vs neoadjuvant). After controlling for all potential confounders in multivariate stepwise regression, these same factors were also found to be independent predictors of recurrence. In the survival analysis, these same factors, in addition to receipt of radiation were found to be predictive of survival.

Conclusions: Approximately 25 % of patients with TNBC experienced a locoregional and/or distant recurrence, resulting in greater than 75 % breast cancer-specific mortality for those who experienced a distant recurrence. The lack of targeted therapy for this aggressive breast cancer subtype likely contributed to this finding.