OBJECTIVES: Breast cancer (BC) is a heterogenous disease with different subtypes. BRCA1/2mut BC represents ~5% of all BC. Recently, targeted treatments became available for HER2- BRCA‑associated ABC. In order to understand the baseline economic burden of HER2- BRCA1/2mut ABC prior to the availability of poly (ADP-ribose) polymerase (PARP) inhibitors, real-world treatment patterns and HRU were evaluated among these patients.
METHODS: Oncologists retrospectively reviewed charts (July-October 2019) of randomly selected patients ≥18 years, with HER2- BRCA1/2mut ABC who received ≥1 cytotoxic chemotherapy (CT) regimen(s) for ABC between January 2013-April 2018. Differences in proportion of healthcare visits by HR status was assessed via X2. Mean (SD) for number of visits per month were reported.
RESULTS: 203 patients were included: 99.5% were female and 76.4% were white. Median age was 58.0 years. 87.2% had a germline (g) BRCA1/2mut, 8.4% had somatic (s) BRCA1/2mut, and 4.4% had sBRCA1/2mut/unknown gBRCA1/2 status. 62.6% had advanced triple negative breast cancer (TNBC) and 37.4% had HR+/HER2– ABC. In TNBC patients (n=127), 1st‑line ABC therapy included non-platinum-based CT (58.3%) and platinum-based CT (41.7%). In HR+/HER2- patients (n=76), common 1st‑line ABC therapies were CT- (73.7%) or endocrine-based (25.0%). A greater proportion of TNBC patients had emergency room (ER) visits and inpatient hospitalizations vs HR+/HER2- patients (ER visits; 14.3% vs 9.2%, P=0.29; inpatient admission; 11.9% vs 1.3%, P=0.01). Higher mean (SD) visits per month were observed in TNBC vs HR+/HER2- patients (ER visits; 0.67 [1.22] vs 0.23 [0.12]; inpatient admissions; 0.58 [0.66] vs 0.29 [not estimable]).
CONCLUSIONS: Among HER2- BRCA1/2mut ABC patients, CT use was common and frequent healthcare visits were observed in the 1st‑line ABC setting. BRCA1/2mut advanced TNBC patients incurred greater HRU than HR+/HER2- patients. Opportunities exist to implement treatment strategies that may reduce the HRU burden in HER2- BRCA1/2mut ABC such as chemotherapy-free treatment options (e.g. targeted agents).
