Abstract PR10: Emergency department-mediated cancer diagnosis in the United States
Authors: Thompson Caroline A. , Sheridan Paige , Murphy James D. , Lyratzopoulos Georgios 
Published: September 2020

Abstract
Background: It is estimated that 20-50% of breast, colon, and lung cancers are diagnosed in an emergency department (ED) globally. Cancer diagnosis via the ED increases time to treatment, worsens short-term survival, and reduces quality of care. Studies in Europe have shown that older, racially diverse, and socioeconomically deprived patients are at a higher risk of ED diagnosis. However, no studies in the U.S. have reported patterns of cancer patients initially presenting to the ED. We identified and characterized patients who were diagnosed with a malignant tumor following presentation to an ED using data from the Surveillance, Epidemiology and End Results (SEER) Medicare-linked database.
Methods: We studied 415,395 Medicare beneficiaries with histologically confirmed first malignant invasive tumors of the breast, colon and rectum, lung, and prostate between 2004 and 2013. Patients were excluded if they did not have continuous coverage in the year prior to diagnosis, had more than one primary tumor, or were diagnosed after death. ED-mediated diagnosis was defined as having at least one ED claim in the month before the date of cancer diagnosis. Covariate adjusted generalized linear models were used to estimate prevalence odds ratios for race/ethnicity, comorbidity, and income levels. A secondary analysis examined associations stratified by the presence of an outpatient clinic visit in the year prior to diagnosis as a proxy for having any usual source of care.
Results: Overall, 42,186 (11%) of cancer diagnoses were ED-mediated (by site: breast: 5%, colorectal: 13%, lung: 15%, prostate: 6%). Patients presenting to the ED were more likely to be: unmarried (OR:1.32; 95% CI: 1.29-1.34), Hispanic (OR:1.47; 95% CI: 1.37-1.57) or Black (OR:1.41; 95% CI:1.37-1.45), have 3+ comorbidities (OR:3.08; 95% CI: 3.00-3.16), and in the lowest income quartile (OR:1.26; 95% CI:1.21-1.30). In stratified analyses income was more strongly associated with emergent presentation among patients with no usual source of care.
Conclusions: This is the first study to describe patterns and predictors of ED-mediated cancer diagnosis in the U.S. We found that minority patients and those with lower SES were more likely to present with cancer via the ED. While some cancers diagnosed in the ED may indicate incidental findings, later-stage symptomatic cancers not identified until they become an emergency may reflect the failure of public health campaigns and primary care services. Reducing emergency presentation of cancer patients may improve patient outcomes and health care system efficiency. Further research is needed to uncover symptomatic and incidental pathways to diagnosis and to identify targets for interventions.
This abstract is also being presented as Poster A132.
Citation Format: Caroline A. Thompson, Paige Sheridan, James D. Murphy, Georgios Lyratzopoulos. Emergency department-mediated cancer diagnosis in the United States [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr PR10.