The prognostic significance of age in operated and non-operated colorectal cancer

BACKGROUND: The prognostic significance of age in colorectal cancer remains controversial. Our purpose was to determine the impact of age at diagnosis on cause- specific survival and overall survival in patients with colorectal cancer. METHODS: Using Surveillance, Epidemiology, and End Results (SEER) population-based data, we identified 226,430 patients with colorectal cancer diagnosed between 1996 and 2005. Patients were separated into 10-year age groups. Five-year cancer cause-specific survival and overall survival data were obtained. Kaplan-Meier methods were adopted and multivariable Cox regression models were built for the analysis of long-term survival outcomes and risk factors. RESULTS: In the operated group, those aged 51–60 had the best prognosis with 5-year cause-specific survival of 72.3% and 5-year overall survival of 68.3%.In the non-operated group, those of young age 15–30 had the best prognosis with 5-year cause-specific survival of 21.2% and 5-year overall survival of 18.2%, and there was continued worsening in cause-specific survival and overall survival with increasing age, except for a small increase in the 51–60 age group (P < 0.001). Multivariable analysis demonstrated a statistically significant disadvantage in cause-specific survival in patients older than 60 (P < 0.001), but the difference between the 51–60 age group and the younger age group (15–30, 31–40, 41–50) wasn’t statistically significant (P > 0.05) in both operated and non-operated patients. CONCLUSIONS: There was no apparent difference in survival in colorectal cancer patients 60 and younger, but in those older than 60 years, there was worsening in overall survival and cause-specific survival in both operated and non-operated patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12885-015-1071-x) contains supplementary material, which is available to authorized users.