Screening-detected colorectal cancers show better long-term survival compared with stage-matched symptomatic cancers
Purpose: the aim of this study was to compare overall and disease-free survival among patients with colorectal cancer detected via a screening program as compared to those with symptomatic cancer.
Material and methods: patients diagnosed via colonoscopy (screening group) and those with clinical symptoms (non-screening) were identified from 1995 to 2014. Demographic, clinical, surgical and pathologic variables were recorded. Stage I, II and III cancers were included. Overall and disease-free survival were calculated at five and ten years after tumor resection and survival was calculated by matching both groups for cancers at stage I, II and III.
Results: two hundred and fifty patients were identified as a result of screening procedures and 1,330 patients presented with symptomatic cancers.There were no significant differences in the baseline characteristics between the two groups. Pathologic stage, degree of differentiation, perineural invasion and lymphovascular invasion were lower in the screening group (p < 0.01). Overall and disease-free survival at five and ten years were higher in the screening group (p < 0.01). However, when the subjects were matched for pathologic stage, significant differences were found between the two groups with regard to stage I and III tumors. Disease-free survival in stage III at five years (79.1 vs 61.7%; p < 0.001) and ten years (79.1% vs 58.5%; p < 0.001) were significantly higher in the screening group.
Conclusions: patients with stage I and III tumors that were diagnosed via a screening program have a higher overall and disease-free survival at five and ten years.