Purpose — This study compares the long-term survival of young adults with colorectal cancer who lived a minimum of 5 years after diagnosis with a cancer-free control population.
Methods — A population-based study was conducted using cancer registry and administrative data. Persons aged 20 to 44 years in whom colorectal cancer was diagnosed between 1992 and 1999 and who lived at least 5 years after diagnosis were identified using the Ontario Cancer Registry. Patients with colorectal cancer were matched 1:5 to randomly selected controls (who were cancer free at the corresponding date of diagnosis) by use of the Registered Persons Database of Ontario based on age, sex, and geographic location. Time-to-death was compared between patients with colorectal cancer and controls by use of Kaplan-Meier estimates and Cox proportional hazard regression.
Results — Nine hundred seventeen young adults with colorectal cancer who lived at least 5 years after diagnosis and 4585 controls were identified. The median follow-up after achieving 5-year survivor status was 6.2 years; 9.5% (87) of patients with colorectal cancer died compared with 1.2% (56) of controls (P < .0001). 62.1% of deaths In the colorectal cancer patient population were attributed to malignant disease. Colorectal cancer patients were significantly more likely to die over time than controls (hazard ratio, 8.2; 95% CI (5.8, 11.6)). Those patients with no evidence of disease recurrence within the first 5 years after diagnosis also remained at an increased risk of death (hazard ratio, 2.0, 95% CI (1.2, 3.6)).
Conclusions — Young adult 5-year survivors of colorectal cancer remain at a higher risk of long-term death than age-matched controls.