title: A colorectal cancer prediction model using traditional and genetic risk scores in Koreans.
abstract: BACKGROUND
  Genome-wide association studies have identified numerous single nucleotide polymorphisms (SNPs) as associated with colorectal cancer (CRC) risk in populations of European descent. However, their utility for predicting risk to CRC in Asians remains unknown. A case-cohort study (random sub-cohort N=1,685) from the Korean Cancer Prevention Study-II (KCPS-II) (N=145,842) was used. Twenty-three SNPs identified in previous 47 studies were genotyped on the KCPS-II sub-cohort members. A genetic risk score (GRS) was calculated by summing the number of risk alleles over all SNPs. Prediction models with or without GRS were evaluated in terms of the area under the receiver operating characteristic curve (AUROC) and the continuous net reclassification index (NRI).
  
  
  RESULTS
  Seven of 23 SNPs showed significant association with CRC and rectal cancer in Koreans, but not with colon cancer alone. AUROCs (95% CI) for traditional risk score (TRS) alone and TRS plus GRS were 0.73 (0.69-0.78) and 0.74 (0.70-0.78) for CRC, and 0.71 (0.65-0.77) and 0.74 (0.68-0.79) for rectal cancer, respectively. The NRI (95% CI) for a prediction model with GRS compared to the model with TRS alone was 0.17 (-0.05-0.37) for CRC and 0.41 (0.10-0.68) for rectal cancer alone.
  
  
  CONCLUSIONS
  Our results indicate genetic variants may be useful for predicting risk to CRC in the Koreans, especially risk for rectal cancer alone. Moreover, this study suggests effective prediction models for colon and rectal cancer should be developed separately.
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, South Korea. KJJUNG@yuhs.ac.
authors.forename: Keum Ji
authors.initials: KJ
authors.lastname: Jung
authors.affiliation: The Catholic University of Korea, Seoul Saint Mary's Hospital, Seoul, South Korea. twrainmaking@gmail.com.
authors.forename: Daeyoun
authors.initials: D
authors.lastname: Won
authors.affiliation: Institute for Health Promotion and Department of Epidemiology and Health Promotion, Graduate School of Public Health, Yonsei University, 50 Yonse-ro, Seodaemun-gu, Seoul, South Korea. CHRISTINAJ@yuhs.ac.
authors.forename: Christina
authors.initials: C
authors.lastname: Jeon
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, South Korea. SORIUL@yuhs.ac.
authors.forename: Soriul
authors.initials: S
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea. taeilkim@yuhs.ac.
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Kim
authors.affiliation: Institute for Health Promotion and Department of Epidemiology and Health Promotion, Graduate School of Public Health, Yonsei University, 50 Yonse-ro, Seodaemun-gu, Seoul, South Korea. jsunha@yuhs.ac.
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Jee
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. tbeaty1@jhsph.edu.
authors.forename: Terri H
authors.initials: TH
authors.lastname: Beaty
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D020641:Polymorphism, Single Nucleotide; D016016:Proportional Hazards Models; D012372:ROC Curve; D012042:Registries; D056910:Republic of Korea / Q000453:epidemiology; D012306:Risk; D012307:Risk Factors