Figure 1.

Flow chart of the study.
Of 1027 invited subjects, 201 were excluded from the study because they provided only fecal immunochemical test for hemoglobin (FIT) or M2-type pyruvate kinase (M2-PK) fecal sample, whereas 254 (24.7%) did not respond to the invitation. Overall, 572 out 1027 subjects underwent both FIT and M2-PK assessment (response rate 55.7%). Subjects with at least one positive fecal test were invited to undergo colonoscopy. Among the 93 participants with at least one positive test (positivity rate 16.3%), 13 subjects declined further investigations or performed colonoscopy elsewhere due to the waiting time for endoscopic examination, whereas 80 subjects underwent colonoscopy (86.0% attendance rate). Of these, 8 subjects reported negative results for neoplasm, 65 subjects were detected with an adenoma that was classified as advanced in 19 cases, and 7 colorectal cancers were diagnosed.