Comparing time to diagnosis and treatment between younger and older adults with colorectal cancer: a population-based study

Background — Younger adults (<50 years) with colorectal cancer may have prolonged delays to diagnosis and treatment that are associated with adverse outcomes. We aimed to compare delay intervals by age for CRC patients in a large population.

Methods — This was a population-based study of adults diagnosed with CRC in Ontario, Canada from 2003 to 2018. We measured time between presentation and diagnosis (diagnostic interval), diagnosis and treatment start (treatment interval), and the time from presentation to treatment (overall interval). We compared interval lengths between adults <50 years, 50-74 years, and 75-89 years using multivariable quantile regression.

Results — 90,225 patients with CRC were included. Of these, 6,853 patients (7.6%) were <50 years. Younger patients were more likely to be female, present emergently, have Stage IV disease, and have rectal cancer compared to middle-aged patients. Factors associated with significantly longer overall intervals included female sex (8.7 days, 95% CI 6.6 to 10.9) and rectal cancer compared to proximal colon cancer (9.8 days, 95% CI 7.4 to 12.2) After adjustment, adults <50 had significantly longer diagnostic intervals (4.3 days, 95% CI 1.3 to 7.3), and significantly shorter treatment intervals (-4.5 days, 95% CI -5.3 to -3.7) compared to middle-aged patients. However, there was no significant difference in the overall interval (-0.6 days, 95% CI -4.3 to 3.2). In stratified models, younger adults with Stage IV disease who presented emergently and patients older than 75 years had longer overall intervals.

Conclusions — Younger adults present more often with Stage IV colorectal cancer but have overall similar times from presentation to treatment as screening-eligible older adults.