Triple negative breast cancer - prognostic factors and survival

Background. Triple negative breast cancer (TNBC) is defined by a lack of expression of both estrogen (ER) and progesteron (PgR) receptors as well as human epidermal growth factor receptor 2 (HER2). Our retrospective analysis addressed prognostic factors for short-and long-term outcomes of patients (pts) with TNBC pts treated in routine clinical practice. Patient and methods. Our retrospective study included 269 TNBC treated at Institute of Oncology Ljubljana between March 2000 and December 2006. The collected data included patients', tumours' and treatments' characteristics. The survival analyses were performed using the Kaplan-Meier method. The Cox proportional hazard model was used in the multivariate analysis. Results. The median age of our patients was 55.3 yrs (23-88.5) and the median follow-up was 5.9 yrs (0.3-9.6). Six (2%) pts experienced local only, 79 (92%) pts distal recurrence and 66 (24%) died. The predominant localisation of the first relapse was in visceral organs (70.4%). The 5-year disease-free survival (DFS) for the entire group was 68.2% and the 5-year overall survival (OS) was 74.5%. We found a pattern of high recurrence rate in the first 3 years following the diagnosis and a clear decline in recurrence rate over the next 3 years. In the univariate analysis age, nodal status, size and lymphovascular invasion (LVI) were found to have a significant impact on DFS as well as on OS. In the multivariate analysis only age (HR=1.79; 95% CI=1.14-2.82; p=0.012) and nodal status (HR=2.71; 95% CI=1.64-4.46; p<0.001) retained their independent prognostic value for DFS and for OS only the nodal status (HR=2.96; 95% CI=1.51-5.82; p=0.002). Conclusions. In our series of TNBC pts nodal status and age (older than 65 yrs) were found to be independent prognostic factors for DFS, whereas for OS only the nodal status. We found a pattern of a high recurrence rate in the first 3 years following the diagnosis and a decline in the recurrence rate over the next 3 yrs with higher rate of distal versus local recurrence and a predominant localization of distal metastases in visceral organs.