title: Should prior FIT results be incorporated as an additional variable to estimate risk of colorectal neoplasia? A prospective study of 5,813 screening colonoscopies.
abstract: BACKGROUND
  Recent studies showed that previous negative results from faecal immunochemical tests (FITs) for colorectal cancer (CRC) screening was associated with lower risk of advanced neoplasia (AN). We evaluated whether prior FIT results should be included to estimate the risk of AN in 2008-2012.
  
  
  METHODS
  A community-based screening practice recruited 5,813 asymptomatic residents aged 50 to 70 years in Hong Kong for CRC screening. We included study participants who had (1). positive FIT with subsequent colonoscopy workup (FIT+ group; n = 356); (2). negative FIT in three consecutive years and received a colonoscopy (FIT- group; n = 857); (3). received colonoscopy without FIT (colonoscopy group; n = 473); and (4). received both colonoscopy and FIT at the same time (combined group; n = 4,127). One binary logistic regression model evaluated whether prior FIT results were associated with colonoscopy findings of AN.
  
  
  RESULTS
  The proportion of participants having AN/CRC was 18.0% (FIT+), 5.5% (FIT-), 8.0% (colonoscopy group), and 4.3% (combined group), respectively. When compared with the colonoscopy group, those in the FIT- group were not significantly more or less likely to have AN/CRC (AOR = 0.77, 95% C.I. = 0.51 to 1.18, p = 0.230). Having one (AOR = 0.73, 95% C.I. 0.48-1.12, p = 0.151) or three consecutive negative FIT result (AOR = 0.98, 95% C.I. 0.60-1.62, p = 0.944) were not associated with lower risks of AN/CRC. Subjects in the FIT+ group was 3.32-fold (95% C.I. 2.07 to 5.32, p < 0.001) more likely to have AN/CRC.
  
  
  CONCLUSIONS
  These findings indicated that subjects with negative FIT findings could be risk stratified similarly as those who had not previously received FIT.
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China; School of Public Health and Primary Care, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Martin C S
authors.initials: MC
authors.lastname: Wong
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Jessica Y L
authors.initials: JY
authors.lastname: Ching
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Victor C W
authors.initials: VC
authors.lastname: Chan
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Shum
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Thomas Y T
authors.initials: TY
authors.lastname: Lam
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Arthur K C
authors.initials: AK
authors.lastname: Luk
authors.affiliation: Institute of Digestive Disease, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Joseph J Y
authors.initials: JJ
authors.lastname: Sung
mesh_terms: D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors