Abstract
Abstract Background: The development of novel anti-HER2 drugs opens new treatment options for patients with breast cancers, including women with lower expression of HER2. The aim of this study was to compare the clinical outcomes of HER2-low and HER2-zero metastatic breast cancer in the real world. Methods: Female patients diagnosed with metastatic breast cancer and low HER2 expression or HER2-zero expression between 2010 and 2017, and who received systematic therapy, were identified from the National Cancer Database (NCDB). The National Cancer Data Base (NCDB) is a nationwide oncology outcomes database that collects information on approximately 70% of all new invasive cancer diagnoses in the United States.HER2-Low was defined as IHC1+ or 2+/ISH negative, whereas HER2-zero was defined as IHC0, based on the American Society of Clinical Oncology/College of American Pathologists guideline. The primary outcome was overall survival(OS). A multivariable Cox regression model was performed to estimate hazard ratios (HR), adjusting for age, race/ethnicity, education, comorbidities, grade, presence of visceral metastasis, and the type of cancer center where patients were treated. The analyses were stratified by hormone receptor status. Results: A total of 22817 of 33417 (68%) were HER2-low and 10600 (32%) were HER2-zero. Hormone receptor-positivity was in 19988 (88%) with HER2-low tumors, whereas 8112 (77%) was in HER2-zero tumors. Women with HER2-low tumors had significantly longer overall survival (OS) than did with Her2-zero tumors in both hormone receptor-positive (median OS 39.0 months vs 37.1 months; adjusted HR: 0.93, 95%CI (0.90-0.96), p<0.001) and hormone receptor-negative groups (median OS 15.8 months vs 14.1 months; adjusted HR: 0.92 95%CI (0.86-0.98), p=0.005). Conclusion: In the metastatic setting, HER2-low tumors have a better survival than HER2-zero tumors, irrespective of hormone receptor status. Specific therapies, such as trastuzmab deruxtecan, have activity in women with HER-low breast cancers and additional therapeutics for HER-2 low should be sought. Citation Format: Changchuan Jiang, Stuthi Perimbeti, Lei Deng, Charles L. Shapiro, Shipra Gandhi. Clinical outcomes in women with metastatic HER2-Low breast cancer in the real world [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4124.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
