Association between genetic susceptibility and mortality in triple-negative breast cancer.

Abstract

e13130 Background: We sought to determine if positive germline genetic tests in patients with triple negative breast cancer (TNBC) was associated with mortality. Methods: Retrospective review. Inclusion criteria: female, 18-85, stage 1-3 TNBC, 2010-2015; 5-year follow-up period from date of cancer diagnosis, or follow-up until death if sooner. Results: Out of the total population of 219 patients, 37.9% (83/219) underwent genetic testing. All patients who underwent genetic testing were Caucasian; most were non-Hispanic (78/83, 94.0%). The average age of the population of patients who underwent genetic testing was 49.6; there were no differences in age between those with a positive genetic test (PT) versus(vs) a negative genetic test (NT) (p=0.963). The average ECOG score was 0.2 and this was similar between the PT and NT groups (p=0.725). The average tumor size was 25.3 and this was similar between PT and NT groups(p=0.992). Among those who underwent testing, a PT was observed in 22.9% (19/83) and a NT in 77.1% (64/83). Within the PT group, 15.8% (3/19) experienced recurrent disease, while 18.8% (12/64) in the NT group experienced recurrent disease (p=1.000).Within the PT group, 5.3% (1/19) were deceased compared with 28.1% (18/64) in the NT group (p=0.590). When recurrent versus nonrecurrent disease was compared regardless of genetic test results, 73.3% (11/15%) in the recurrence group were deceased, compared with 11.8% (8/68) in the non-recurrence group (p<0.001). When the genetic test population was stratified by recurrence, there was no association between genetic test results and living status in recurrent disease (p=0.154), or non-recurrent disease (p=0.183). Conclusions: Most patients who underwent genetic testing were Caucasian, and the average age of the cohort was approximately 49 years. Otherwise, the demographic characteristics were comparable between patients with a positive genetic test and those with a negative genetic test. Positive genetic test results were not associated with recurrent TNBC, or tumor size. However, the presence of recurrence was associated with a higher incidence of mortality, irrespective of genetic test results. Our study shows that genetic susceptibility to breast cancer was not associated with greater mortality. More has to be done to determine if racial disparities occur in offering genetic testing to racial minorities who meet criteria.