Triple Negative Breast Cancer: 10-Year Survival Update of The Applied Treatment Strategy in Kuwait

Triple negative breast cancer (TNBC) is recognized as a distinct clinical and biological entity of poor outcome for almost two decades, yet its treatment strategy still needs to be better specified. The study aim is to update the 10-year survival data of our TNBC patients and to find its association with different treatment modalities.

We updated the 10-year survival data of 359 women diagnosed with TNBC between 1999 and 2009 in the Kuwait Cancer Control Center (KCCC). The overall survival (OS), disease free survival (DFS), distant metastasis free survival (DMFS) and loco-regional recurrence free survival (LRFS) were estimated using Kaplan Meier method. Survival was correlated with different prognostic factors and treatment modalities. Statistical significance was calculated using the log-rank test and defined as p < 0.05. Cox regression is used for Multivariate analysis.

TNBC represented 12% of breast cancer in Kuwait with a median age of 48 years. The stage distribution was as follow: stage I, II, III, IV in 15%, 43%, 35% and 7% of patients respectively. Regarding surgery, 33% had Conservative surgery; 67% had mastectomy; 82% had axillary clearance. Chemotherapy was neoadjuvant in 25%, adjuvant in 56% and palliative in 5% of patients. Two-thirds of patients (67%) received adjuvant radiotherapy. After a median follow-up of 108 months, the 10-year OS, DFS, DMFS and LRFS were 66%, 59%, 72% and 77% respectively. The 10-year OS was 92%, 80%, 49% and 0% for Stage I, II, III and IV respectively (p =< 0.0001). OS was significantly worse with the presence of lymphovascular invasion (LVI) with p = 0.003. OS was not significantly affected by age, grade or treatment modality. In multivariate analysis, the clinical stage and LVI were still significant (P<0.0001 and 0.04 respectively).

In the absence of biological biomarkers, clinical stage and LVI seem to be the only significant prognostic factors for survival of TNBC patients in our study population. Timing of chemotherapy as well as the extent of surgery do not seem to affect the TNBC patients' outcome.