Abstract P6-11-09: Need for increased awareness in high incidence areas of premenopausal de novo stage IV breast cancer
Authors: Baer Lea , Khorasanchi Adam , Stopeck Alison , Kudelka Andrzej , Cohen Jules 
Published: March 2020

Abstract
Introduction: Breast cancer is the most common cancer in women. In 2013, 5% of US women presenting with de novo Stage IV breast cancer cases were under age 40, and 16% under age 50. The purpose of our study was to analyze changes in demographics and clinical characteristics of patients with de novo Stage IV breast cancer at our tertiary care institution with a focus on younger women.
Methods: Our study is a retrospective chart review of 159 female patients who presented with de novo Stage IV breast cancer to our institution during years 2007-2019. Patients with recurrent Stage IV breast cancer were excluded. Charts of patients were reviewed and the following data was recorded: age at diagnosis, race, insurance, menopausal status, symptoms, family history, how cancer was diagnosed, prior breast imaging, genetics testing, tumor histology, and sites of metastasis. Data was further subdivided into younger (under age 50) and older (over age 69) groups.
Results: Data analysis revealed median age of 61 and range of 26-92. 14/159 women (9%) diagnosed with de novo stage IV breast cancer were younger than 40. 40/159 (25%) were younger than 50, and 119/159 (75%) were age 50 or older. Over the last decade, proportion of younger women presenting with de novo Stage IV breast cancer did not change, while 86% increase was seen in older age group.
Among younger women, 72% were Non-Hispanic Whites, 10% Hispanic and 12% Black. Over the last decade, proportion of non-Hispanic whites younger than 50 with de novo Stage IV disease decreased by 38%, 50% increase was seen in Blacks and four-fold increase in Hispanics.
Majority of women noted a breast mass prior to diagnosis, 72% of younger group and 75% older group. 35% of younger group presented with additional symptoms such as bone pain compared to 52% older women. 27% of younger group initially presented with an ulcerated breast lesion compared to 47% older group.
Proportion with family history of breast cancer was similar, 57% in younger group and 52% older group.
90% of younger women had invasive ductal cancer. Tumors were hormone receptor positive in 65% of younger women compared to 82% older group.
90% of younger women were insured, compared to 100% older group. 60% of younger group were diagnosed by their primary care physician compared to 42% older group.
17% younger women had prior breast imaging. All women younger than 50 were offered genetics testing, 10% elected to undergo testing. Of those women, 18% under age 40 and 31% under age 50 were found to have deleterious mutations.
Conclusion: Our study analyzed the demographics and clinical characteristics of younger patients presenting with de novo metastatic breast cancer over the last 10 years. In our tertiary center serving a suburban area, the proportion of women younger than 40 with de novo Stage IV breast cancer was 9% compared to 5% nationwide. Similarly, the proportion younger than 50 was 25% compared to 16% nationwide.
Overall, the proportion of younger women presenting with de novo Stage IV breast cancer has not significantly changed over the past decade. This stability is particularly interesting in view of recent changes in area demographics in which the Hispanic population has increased by 2% over the past 4 years. In our study, the racial breakdown did significantly change with 38% decrease in non-Hispanic whites while 50% increase was seen in Blacks and four-fold increase in Hispanics.
Finally, 90% of younger women were insured suggestive of sufficient access to care. In fact, a majority of the younger were initially diagnosed by their primary care physician. However, only a minority had prior breast imaging highlighting the need for increased awareness and education of both community and primary providers in areas of high incidence of premenopausal Stage IV breast cancer.
Citation Format: Lea Baer, Adam Khorasanchi, Alison Stopeck, Andrzej Kudelka, Jules Cohen. Need for increased awareness in high incidence areas of premenopausal de novo stage IV breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-11-09.