Abstract P1-09-14: Demographic, clinical/disease characteristics, and treatment of patients with germline mutated metastatic breast cancer: A CancerLinQ study
Authors: Dalvi T , Herr I , Maclachlan S , Briceno J , Bennett J , McLaurin K , Hettle R , McCutcheon S 
Published: May 2019

Objective: To describe the demographics, clinical/disease characteristics and treatment patterns of patients with germline BRCA mutated (gBRCAm) metastatic breast cancer (mBC) as compared to those with gBRCA wild type (wt) and those who are untested for gBRCA mutations.

Methods: The CancerlinQ Discovery Database (CLQ), launched by the American Society of Clinical Oncology (ASCO) in 2016, consists of longitudinal, demographic and geographic diverse data aggregated from oncology practice electronic health record (EHR) databases. Natural language processing and technology-enabled curation are utilized to identify records of most interest, followed by manual curation to abstract information from unstructured EHR fields. This cohort consists of 7,889 patients diagnosed with mBC between 1982 and 2018, and is enriched for patients with gBRCA testing through the curation process.

Results: Overall most patients were female (99.0%), white (55.3%), and the median age at mBC diagnosis was 63 years (yrs). The majority were not tested for gBRCA mutation (88.4%); 2.0% were gBRCAm, 9.2% were gBRCAwt, 0.4% had an undetermined test result, and 0.1% had a variant of unknown significance. Among those tested for estrogen-receptor (ER) (n=6,700) and progesterone-receptor (PR) (n=6,737) status, 76.6% were ER positive (+) and 62.2% were PR+. Among those tested for human epidermal growth factor receptor 2 (HER2) (n=6,696), 21.7% were HER2+. Among those with known results for ER, PR, and HER2 (n=6,063), 10.1% were hormone receptor (HR)+/HER2+, 10.6% were HR negative (-)/HER2+, 65.0% were HR+/HER2-, and 14.3% were HR-/HER2-. The median age at mBC diagnosis was 50 yrs for gBRCAm, 51 yrs for gBRCAwt and 64 yrs among the gBRCA untested group. A similar proportion of patients were diagnosed with metastatic disease among the gBRCAm and gBRCAwt groups (25.3% and 20.3%, respectively), while the proportion was higher among the gBRCA untested group (38.0 %). The most common site of metastasis for all groups was bone (35.1% for gBRCAm, 41.7% for gBRCAwt, and 36.5 % for gBRCA untested), followed by liver (16.2% for gBRCAm, 13.3% for gBRCAwt, and 8.5% for gBRCA untested). The most common first-line therapies for gBRCAm patients were tamoxifen (7.7%), letrozole (7.0%), cyclophosphamide+doxorubicin (6.3%), and paclitaxel (6.3%); for gBRCAwt patients they were cyclophosphamide+doxorubicin (6.6%), paclitaxel (6.4%), and tamoxifen (6.4%); and for gBRCA untested patients they were letrozole (11.1%), fulvestrant (9.3%), and tamoxifen (4.6%). The mean number of lines of therapy (including lines of chemotherapy and hormone therapy) were 3.5, 3.8, and 3.4 for the gBRCAm, gBRCAwt, and gBRCA untested groups, respectively.

Conclusions: Patients with gBRCAm were younger than the gBRCA untested group, and more patients had metastatic disease at diagnosis in the gBRCA untested group. Further analyses accounting for HR and HER2 status will be conducted and presented. This is the first example of research using curated breast cancer data from ASCO's CLQ.

Citation Format: Dalvi T, Herr I, Maclachlan S, Briceno J, Bennett J, McLaurin K, Hettle R, McCutcheon S. Demographic, clinical/disease characteristics, and treatment of patients with germline mutated metastatic breast cancer: A CancerLinQ study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-14.