With evolving gBRCAm BC guideline landscape, we present latest gBRCA testing rates among mBC US pts with HR+/HER2- or triple negative BC (TNBC); including clinical outcomes, treatment patterns and HRU in gBRCAm pts.
The Flatiron Health database was used in a real world retrospective analysis of mBC pts with HR+/HER2- or TNBC, ≥18 yrs old, diagnosed between Jan 2011-Feb 2018. Rates of gBRCA testing were assessed. One- to 5-yr overall survival (OS) post mBC diagnosis for gBRCAm HR+/HER2- and TNBC pts were estimated. Cox proportional hazards model was used to estimate OS of TNBC vs HR+/HER2-. Outcomes between TNBC vs HR+/HER2- pts were compared while adjusting for imbalances. Antineoplastic treatment was summarized and HRU patterns were analyzed using t-tests.
The study included 12,021 mBC pts (10,291 HR+/HER2-; 1730 TNBC). Results for gBRCA testing were available for 16.7% of pts overall; (HR+/HER2-: 15.4%, TNBC: 24.2%). The most common 1st line treatments for gBRCAm TNBC were capecitabine (19%) and carboplatin/gemcitabine (15%) and 1st line treatments for gBRCAm HR+/HER2- included letrozole (10%) and fulvestrant (7%). Pts counts, OS estimates and HRU for gBRCAm carriers are shown in the table; Cox regression results showed lower OS for gBRCAm TNBC pts vs gBRCAm HR+/HER2- mBC pts, Hazard Ratio (HR+/HER2- / TNBC) and 95% CI 0.59 (0.34, 1.01). Estimated median OS and 5-yr OS rates are (33.9 mths, 22.3 mths) and (28.9%, 26.4%) for gBRCAm HR+/HER2- and TNBC pts respectively. Number of HRU visits per-pts-per-year were significantly higher among TNBC pts.
gBRCA testing rates among mBC pts with HR+/HER2- or TNBC were low. Among mBC pts with gBRCAm, 5-yr OS rates were < 29% for both HR+/HER2- and TNBC; poor prognosis and HRU burden demonstrates a significant unmet need for more targeted, less HRU-intensive treatment options among these pts.Table: 310P
|Total Patients (N = 12,021) n (%)||10,291 (85.6)||1730 (14.4)|
|Patients with gBRCA test results (n = 2005) n (%)||1587 (79.2)||418 (20.8)|
|Patients with gBRCAm (n = 229) n (%)||165 (72.1)||64 (27.9)|
|gBRCAm patients with ≥ 1st Line antineoplastic treatment (n = 188) n (%)||142 (75.5)||46 (24.5)|
|Year||Overall Survival Estimates (%)|
|Number of Health Resource Utilization Visits (per patient per year) mean (std dev) *p < 0.05|
|Treatment Visits*||17.4 (14.4)||40.8 (21.8)|
|Lab Visits*||24.2 (10.1)||40.3 (44.2)|
|Vital Visits*||27.4 (14.3)||49.9 (66.8)|
|ALL*||35.2 (30.3)||65.0 (84.7)|
Clinical trial identification
Legal entity responsible for the study
R. Quek, J. Mardekian: Employee: Pfizer Inc.