title: A predictive model combining fecal calgranulin B and fecal occult blood tests can improve the diagnosis of colorectal cancer.
abstract: OBJECTIVE
  Current fecal screening tools for colorectal cancer (CRC), such as fecal occult blood tests (FOBT), are limited by their low sensitivity. Calgranulin B (CALB) was previously reported as a candidate fecal marker for CRC. This study investigated whether a combination of the FOBT and fecal CALB has increased sensitivity and specificity for a diagnosis of CRC.
  
  
  METHODS
  Patients with CRC (n = 175), and healthy individuals (controls; n = 151) were enrolled into the development (81 cases and 51 controls) and validation (94 cases and 100 controls) sets. Stool samples were collected before bowel preparation. CALB levels were determined by western blotting. FOBT and fecal CALB results were used to develop a predictive model based on logistic regression analysis. The benefit of adding CALB to a model with only FOBT was evaluated as an increased area under the receiver operating curve (AUC), partial AUC, and reclassification improvement (RI) in cases and controls, and net reclassification improvement (NRI).
  
  
  RESULTS
  Mean CALB level was significantly higher in CRC patients than in controls (P<0.001). CALB was not associated with tumor stage or cancer site, but positivity on the FOBT was significantly higher in advanced than in earlier tumor stages. At a specificity of 90%, the cross-validated AUC and sensitivity were 89.81% and 82.72%, respectively, in the development set, and 92.74% and 79.79%, respectively, in the validation set. The incremental benefit of adding CALB to the model, as shown by the increase in AUC, had a p-value of 0.0499. RI in cases and controls and NRI all revealed that adding CALB significantly improved the prediction model.
  
  
  CONCLUSIONS
  A predictive model using a combination of FOBT and CALB may have greater sensitivity and specificity and AUC for predicting CRC than models using a single marker.
authors.affiliation: Center for Colorectal Cancer, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Center for Cancer Prevention and Detection, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Byung Chang
authors.initials: BC
authors.lastname: Kim
authors.affiliation: Biometric Research Branch, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Jungnam
authors.initials: J
authors.lastname: Joo
authors.affiliation: Center for Colorectal Cancer, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Research Institute and Hospital, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Chang
authors.affiliation: Research Institute and Hospital, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Hyun Yang
authors.initials: HY
authors.lastname: Yeo
authors.affiliation: Research Institute and Hospital, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Byong Chul
authors.initials: BC
authors.lastname: Yoo
authors.affiliation: Biometric Research Branch, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Boram
authors.initials: B
authors.lastname: Park
authors.affiliation: Center for Colorectal Cancer, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Research Institute and Hospital, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: Center for Colorectal Cancer, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Center for Cancer Prevention and Detection, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Research Institute and Hospital, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Dae Kyung
authors.initials: DK
authors.lastname: Sohn
authors.affiliation: Center for Colorectal Cancer, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Center for Cancer Prevention and Detection, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Chang Won
authors.initials: CW
authors.lastname: Hong
authors.affiliation: Center for Colorectal Cancer, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea; Center for Cancer Prevention and Detection, National Cancer Center, Ilsan-gu, Goyang, Gyeonggi, Korea.
authors.forename: Kyung Su
authors.initials: KS
authors.lastname: Han
mesh_terms: D015153:Blotting, Western; D040502:Calgranulin B / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D005243:Feces / Q000737:chemistry*; D006801:Humans; D008962:Models, Theoretical; D009780:Occult Blood
chemical_list: D040502:Calgranulin B