Evaluation of colonoscopy results of patients in a colorectal cancer screening program: A retrospective cohort study

Abstract

Background/Aim: Colorectal cancer is at the forefront of cancer-related deaths. Early detection and treatment of precursor lesions with screening programs are imperative. In this study, we aimed to determine the outcomes of colonoscopy and the effectiveness of screening. Methods: The colonoscopy results of 758 patients who were referred for positive fecal occult blood tests between October 2015 and January 2020 were examined in this retrospective cohort study. The demographic, pathological, and colonoscopic findings were recorded. Results: No pathology was detected in 53.3% of patients during colonoscopy. In patients with a pathology, polyps (28.5%), diverticular disease (15.44%), and colitis (2.37%) were most common. Patients with malignancy accounted for 3.69% of all patients and 12.96% of patients with polyps. Among adenoma types, the risk of dysplasia and/or malignancy was higher in villous polyps compared to tubulovillous and tubular polyps, and in tubulovillous polyps compared to tubular polyps (P<0.01). The presence of dysplasia and/or malignancy was evaluated mutually between the subgroups according to polyp size. There was no significant difference in the incidence of dysplasia between the patients with polyps of 6-10 mm and those with polyps of 11-20 mm (P=0.192). Among all other subgroups, an increase in polyp size caused a significant increase in dysplasia and/or malignancy (P<0.001). Conclusion: The results of this study showed that colonoscopy performed on colorectal cancer screening patients with a positive fecal occult blood test was quite successful in diagnosing precancerous lesions and colorectal cancer.