Abstract P3-07-25: 2 year survival analysis of triple negative breast cancer from SEER data
Authors: Rushton Moira , Zhang Tinghua , Song Xinni 
Published: May 2015

Background

Triple negative breast cancer (TNBC) is a heterogeneous disease characterized by the lack of receptor expression (ER, PR and Her 2/neu negative). Amongst breast cancer types TNBC has a less favourable prognosis. There is a higher incidence of TNBC in African-American women than Caucasian women. What has not been clearly elucidated is whether survival outcomes are different among women with TNBC from different ethnic background.

Objective

The objective of our study was to use population data to determine if significant differences exist in overall survival (OS) of TNBC patients across various ethnicities, including but not limited to–white, black, Hispanic and Asian.

Methods

Retrospective cohort study of patients with TNBC from 1973-2011 Surveillance, Epidemiology, and End-Results (SEER) database to examine differences in OS across ethnicities. For each case data was collected on age, race, disease stage, treatment, insurance status, time to death and cause of death. Descriptive statistics and survival analysis was carried out on the data. Multivariate analysis was carried out to take into account age, stage, treatments received.

Results

12894 cases of TNBC across all ethnicities were reported in the SEER database. At two years follow-up, 720 patients (5.7%) had died of breast cancer. 9696 (78.77%) had early stage (stage 0 – II) disease, 1885 (15.31%) had locally advanced/stage III disease while 728 (5.9%) had stage IV disease. 12071 (95.53%) were insured, 11533 (91.27%) had surgery, and 5454 (43.17%) had radiation therapy. 7746 (61.53%) patients were white, 2429 (19.29%) black, 1548 (12.30%) were Hispanic and 490 (3.89%) were Asian. In multivariate analysis, increasing age, stage III or IV disease, lack of insurance, surgery or radiation all had significant hazard ratios. There was no significant survival difference found between any ethnicity compared with white patients when controlled for age, stage, insurance, surgery and radiation.

Discussion

After two-year follow-up of large cohort of TNBC patients no significant difference could be found between any ethnicity and the white population with this disease. While there is a large population of black and Hispanic patients in this study there are small numbers of other races. The small relatively small event rate could be masking potential differences given the majority if patients were early stage and are still alive. Longer follow-up is needed before conclusions can be made about differences between ethnic groups. if certain populations do worse will inform the medical oncology community of an area to focus greater research into how to optimize therapies for that patient group.

Citation Format: Moira Rushton, Tinghua Zhang, Xinni Song. 2 year survival analysis of triple negative breast cancer from SEER data [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-07-25.