34 Demographics, Clinical Characteristics, and Treatment Patterns for Patients With BRCA-Mutated, HER2-Negative Early-Stage Breast Cancer: a CancerLinQ Real-World US Study

Stella Mokiou, PhD¹; Richard W. DeClue, PhD, MPH²; Santosh Gautam, PhD²; Lisa Herms, PhD²; Miao Jiang, PhD³; Ping Sun, PhD⁴; Susan McCutcheon, PhD⁴; Vered Stearns, MD⁵; Maria Raquel Nunes, MD⁵

¹AstraZeneca, Cambridge, England, UK; stella.mokiou@astrazeneca.com

²ConcertAI, Memphis, TN

³AstraZeneca, Gaithersburg, MD

⁴AstraZeneca, Cambridge, England, UK

⁵Johns Hopkins School of Medicine, Baltimore, MD

Background

Despite several reports of the real-world clinical characteristics and treatment patterns of patients with early-stage breast cancer (ESBC), specific information is lacking for patients with BRCA-mutated (BRCAm) ESBC. We conducted a retrospective study focusing on patients with BRCAm, HER2-negative (HER2–) ESBC, including both hormone receptor–positive (HR+) and –negative (HR–), as well as triple-negative breast cancer (TNBC).

Materials and Methods

We identified patients ( 18 years) from the CancerLinQ electronic medical record database, diagnosed with stage I through IIIA HER2– breast cancer between January 1, 2014 and January 1, 2019. BRCA mutation status was determined based on available test results: BRCAm, wild-type BRCA (BRCAwt), or unknown/untested (BRCAunk). Patient characteristics and treatments were summarized by BRCA status for HR+ and TNBC cohorts. AstraZeneca– ConcertAI Confidential and Proprietary Information Version 3.0 Page 2 of 2 January 13, 2021.

Results

In total, 4566 patients (BRCAm = 41; BRCAwt = 492; BRCAunk = 4033) were identified in the HR+ cohort and 703 (BRCAm = 20; BRCAwt = 135; BRCAunk = 548) in the TNBC cohort. Patients with BRCAm were younger and received surgery plus adjuvant therapy more frequently, whereas fewer patients received radiation versus BRCAwt and BRCAunk overall. Among the HR+ cohort, 68.3% of patients with BRCAm were stage II or IIIA at diagnosis (vs 46.5% BRCAwt and 40.4% BRCAunk), and 53.7% had a poorly differentiated grade 3 tumor (vs 19.9% BRCAwt and 16.3% BRCAunk). Clinical characteristics were similar

by BRCA status for the TNBC cohort. Among patients receiving neoadjuvant treatment (n = 282 [6.2%] HR+; n = 206 [29.3%] TNBC), doxorubicin plus cyclophosphamide and either paclitaxel or docetaxel (AC-T regimen) was the most common therapy (42.9%, HR+; 50.0%, TNBC). Among patients with HR+ disease, 66.7% of those with BRCAm disease received AC-T alone; among those with TNBC, 71.4% patients with BRCAm disease received AC-T alone. Among patients with HR+ disease receiving adjuvant treatment (n = 2641; 57.8%), 63.4% received hormonal therapy and 9.6% received both AC-T and hormonal therapy. Among those with HR+ and BRCAm, 31.0% received adjuvant AC-T/hormonal therapy. Among patients with TNBC receiving adjuvant treatment (n = 370; 52.6%), 31.6% received AC-T alone (similar across BRCA groups), with 92.3% BRCAm receiving chemotherapy.

Conclusions

This study provides insight into characteristics and treatment patterns of patients with BRCAm ESBC in real-world oncology settings in the United States. Consistent with prior studies, patients with BRCAm were diagnosed at a younger age, and for the HR+ cohort, with higher tumor grade and at a later disease stage. The use of chemotherapy, in both neoadjuvant and adjuvant settings, was more frequent for patients with BRCAm.

Sponsor: AstraZeneca