Clinical characteristics of patients diagnosed with triple negative breast cancer in Cyprus: a retrospective analysis

Abstract

Trible Negative Breast Cancer (TNBC) is a distinct subtype of Breast Cancer (BC) defined by the absence of Hormone and HER2 receptors on the cell surface of cancer cell. TNBC absence of hormone receptor suggests lack of target specific treatment and chemotherapy remained as the major therapeutic option for systemic treatment until recently. TNBC is connected with worse prognosis and high rate of recurrence during the first 5 years after diagnosis. In this retrospective study an analysis of clinical characteristics of patients diagnosed with TNBC and treated in Bank of Cyprus Oncology Center in the decade 2008-2017 was conducted. Data was collected from electronic registry and medical documents of the patients. 330 women were included in TNBC cohort and 25 women in weak HR positive cohort. Patients median Age of Diagnosis was 58 years old. Only 0,92% of the patients were diagnosed with de novo metastatic disease. 5-year OS rate was evaluated at 75,41% and median OS did not reach at the end of follow-up. The Median Ki67 score was 60%. 10,95% of the examined patients had germline BRCA1 (5,84%) or BRCA2 (5,11%) mutations. Stage (HR 1,5; p<0,0001) and Ki67% were poor prognostic factors whereas Anthracycline based chemotherapy regiment on adjuvant or neoadjuvant setting was connected with favorable prognosis compared to non-Anthracycline based chemotherapy regiments (HR 0,51; p<0,0001). 69 patients (21,1%) presented relapse (local or systemic) during follow-up period. Median OS after recurrence was 23 months. Patients with systemic relapse had shorter OS (HR 3,52, p=0,004). Most common site of metastasis was lower respiratory tract (59,42%). 36,23% of patients that recurrence occurred presented CNS involvement (brain metastasis or leptomeningeal disease). Management of recurrent and metastatic TNBC remains challenging. Better understanding of TNBC, which presents genetic and genomic variability, is needed for the development of novel therapeutic agents and specific biomarkers based on precision medicine.