Abstract
BACKGROUND: The incidence of rectal cancer in patients younger than 50 years is increasing. To test the hypothesis that the biology in this younger cohort may differ, this study compared survival patterns, stratifying patients according to National Comprehensive Cancer Network (NCCN) guideline-driven care and age. METHODS: The National Cancer Data Base was queried for patients treated with curative-intent transabdominal resections with negative surgical margins for stage I to III rectal cancer between 2004 and 2014. Outcomes and overall survival for patients younger than 50 years and patients 50 years old or older were compared by subgroups based on NCCN guideline-driven care. RESULTS: A total of 43,106 patients were analyzed. Younger patients were more likely to be female and minorities, to be diagnosed at a higher stage, and to have travelled further to be treated at academic/integrated centers. Short- and long-term outcomes were significantly better for patients younger than 50 years, with age-specific survival rates calculated. Younger patients were more likely to receive radiation treatment outside NCCN guidelines for stage I disease. In younger patients, the administration of neoadjuvant chemoradiation for stage II and III disease was not associated with an overall survival benefit. CONCLUSIONS: Age-specific survival data for patients with rectal cancer treated with curative intent do not support an overall survival benefit from NCCN guideline-driven therapy for stage II and III patients younger than 50 years. These data suggest that early-onset disease may differ biologically and in its response to multimodality therapy.