The role of the emergency department in cancer diagnosis: comparing diagnostic and treatment intervals.

OBJECTIVES: Cancers diagnosed through the emergency department (ED) were identified, and their characteristics, and diagnostic and treatment intervals were compared to community-diagnosed cases. METHODS: A medical records review was conducted for new cancer cases seen by medical oncology at The Ottawa Hospital from January 1 to March 31, 2024. Enrolled cases were assessed for ED visits in the preceding 3 months and classified as ED diagnosed if the cancer was diagnosed as a result of the ED visit. An equal number of cases without a preceding ED visit were randomly selected as community-diagnosed comparators. Patient characteristics, Ontario Marginalization Index scores, cancer type and stage, screen detection, diagnostic assessment pathway eligibility and referral, diagnostic timelines, treatment, and mortality were abstracted. RESULTS: Among 1011 new cancer cases, 241 (23.8%) had an ED visit within 3 months and 129 (12.8%) were ED diagnosed. ED-diagnosed patients were more comorbid, from more racially diverse/immigrant dense areas and were less often female. Lung, brain, and colorectal cancers predominated ED-diagnosed cases, while screen-detected breast cancer was most common in community-diagnosed cases. ED-diagnosed cases were more frequently stage IV (65.1% versus 17.3%; p < 0.001) with higher one-year mortality (38.8% versus 7.0%; p < 0.001). Over 80% of all individuals were attached to a primary care provider, more so in community-diagnosed cases (82.2% versus 95.3%; p = 0.001). ED diagnosis was associated with acute symptoms (89.9%) and acceleration of workup (40.3%). ED-diagnosed cases had shorter diagnostic intervals (19 versus 84 days, p < 0.001), largely due to imaging and biopsy timelines, as well as shorter treatment intervals (21 versus 55 days, p < 0.001). CONCLUSION: Community-diagnosed cancers took about four times longer than ED cases to be diagnosed, primarily related to imaging and biopsy timelines, with high levels of primary care attachment noted for all patients. Acute symptoms and acceleration of diagnosis were the most common reasons for ED diagnosis. These findings suggest that dedicated diagnostic pathways for suspected cancers could enable timely diagnosis and improve outcomes.