Hormone Receptor–Positive/Human Epidermal Growth Receptor 2–Negative Metastatic Breast Cancer in Young Women: Emerging Data in the Era of Molecularly Targeted Agents
Open Access
- 16 March 2020
- journal article
- research article
- Published by Oxford University Press (OUP) in The Oncologist
- Vol. 25 (6), e900-e908
- https://doi.org/10.1634/theoncologist.2019-0729
Abstract
Breast cancer is the most common malignancy in young women worldwide, accounting for an estimated 30% of new cancer diagnoses and 25% of cancer deaths. Approximately two thirds of young women with breast cancer have hormone receptor–positive (HR+)/human epidermal growth receptor 2–negative (HER2−) tumors. Numerous studies, primarily in early‐stage breast cancer, have demonstrated that young age is an independent risk factor for more aggressive disease and worse outcomes. Although more limited data are available regarding outcomes in young patients with advanced disease, these age‐related disparities suggest that breast cancer in premenopausal women has distinct clinicopathologic and molecular features that can impact treatment outcomes. Until recently, limited data were available on the intrinsic molecular subtypes and genetics of young patients with HR+/HER2− metastatic breast cancer (mBC). In this review, we explore insights into the clinical and pathologic features of HR+/HER2− mBC in younger women derived from recent clinical trials of the cyclin‐dependent kinase 4/6 inhibitors palbociclib (PALOMA‐3), ribociclib (MONALEESA‐7), and abemaciclib (MONARCH 2) and the implications of these findings for clinical practice, guideline development, and future research. Implications for Practice This review provides clinicians with an overview of emerging data on the unique clinicopathologic and molecular features of hormone receptor–positive/human epidermal growth receptor 2–negative metastatic breast cancer (mBC) in premenopausal women, summarizes findings from the most recent clinical trials of endocrine‐based treatment in this patient population, and explores the implications of these findings for clinical practice, guideline development, and future research. Improved understanding of the key factors influencing disease course and treatment response in premenopausal patients with mBC may lead to more timely incorporation of evidence‐based treatment approaches, thereby improving patient care and outcomes.Keywords
Funding Information
- Pfizer Inc (N/A)
This publication has 65 references indexed in Scilit:
- Integrative Analysis of Complex Cancer Genomics and Clinical Profiles Using the cBioPortalScience Signaling, 2013
- Incidence of Breast Cancer With Distant Involvement Among Women in the United States, 1976 to 2009JAMA, 2013
- Molecular biology in breast cancer: Intrinsic subtypes and signaling pathwaysCancer Treatment Reviews, 2012
- Impact of Breast Cancer Subtypes and Treatment on Survival: An Analysis Spanning Two DecadesCancer Epidemiology, Biomarkers & Prevention, 2012
- Comprehensive molecular portraits of human breast tumoursNature, 2012
- The cBio Cancer Genomics Portal: An Open Platform for Exploring Multidimensional Cancer Genomics DataCancer Discovery, 2012
- Breast Cancer in Young Women: Poor Survival Despite Intensive TreatmentPLOS ONE, 2009
- Breast Cancer Before Age 40 YearsSeminars in Oncology, 2009
- Elevated Breast Cancer Mortality in Women Younger than Age 40 Years Compared with Older Women Is Attributed to Poorer Survival in Early-Stage DiseaseJournal of the American College of Surgeons, 2009
- Young Age at Diagnosis Correlates With Worse Prognosis and Defines a Subset of Breast Cancers With Shared Patterns of Gene ExpressionJournal of Clinical Oncology, 2008