The Epidemiology, Clinico-Pathologic and Prognostic Characteristics of Triple-Negative Breast Cancer Compared with Non Triple-Negative Breast Cancer.
Authors: Kwong A. , Wong K. , Wong C. , Leung C. 
Published: December 2010

BackgroundTriple negative breast cancers (TNC) are increasingly reported to be associated with higher grade cancers and worse prognosis. TNC are also known to be associated with BRCA mutation. There have also been reports that apart from differences biologically, reproductive, socio-demographics factors such as age of menarche, age of pregnancy, parity, body mass index may influence the development of TNC. The importance of variations in different ethnicities based on studies on Caucasians and African-Americans (AA) have been emphasized. This study aims to look at the tumor characteristics and factors which may influence the presentation and prognosis of TNC in a cohort of Chinese women.Materials and MethodA retrospective review was performed in a prospectively collected database of breast cancer patients between 1996-2007. Clincopathological, epidemiological variables and clinical outcomes were evaluated.ResultsA total of 924 women with breast cancer were included in this cohort of which 142 (8.2%) had TNC and 782 (45.2%) had non TNC. There was no significant difference in age of presentation in both groups (mean age 52.5 vs 52.1 years old). TNC significantly more likely to be associated with higher grade (p&lt;0.01), and are more likely to have lymphovascular invasion (LVI)(p=0.018). There are no significant differences between nodal stage, histological type (invasive vs. in situ), and overall stage at presentation. The median follow up was 4 years. There is no statistically difference in disease free survival (DFS) (3 yr-DFS-61.1% vs. 76%) and Overall survival (OS) (3yr-OS 68.9% vs. 78.5%) although both DFS and OS are worse in TNC. Visceral relapse rate are similar in both groups but a slightly higher rate of bone relapse in TNC group (11.1% vs. 6.9%) though not statistically significant. Although there are no differences in the overall local relapse rate, subanalysis found that after lumpectomy, TNC are more likely to recur (17.7% vs. 3.4%). Higher BMI (p=0.08), shorter duration of breast feed p=0.034), lower parity (p=0.005) are all associated with TNC whereas there are no associations with age of menarche or menopause and age of first pregnancy. 23.7% of a subset of TNC patients who undertook BRCA testing were found to be mutation carriers.DiscussionThe percentage of TNC in this cohort is smaller than that reported in the West. Unlike the West, TNC did not present at a younger age. Although TNC and Non TNC have similar stage of presentation, the DFS and OS are worse in TNC which may be explained by the higher histological grade and likely more aggressive biological characteristics. Local recurrence rate after lumpectomy is also higher in TNC which may be related to higher rate of LVI. There are similarities and differences in associated socio-demographic factors compared to the West and a higher rate of BRCA mutation in TNC. Larger-scale study on different ethnicities will increase our understanding in TNC to achieve more personalized management.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3071.