title: [Risk prediction of colorectal cancer with common genetic variants and conventional non-genetic factors in a Chinese Han population].
abstract: OBJECTIVE
  To understand the association between multiple genetic loci identified by genome-wide association studies (GWASs) and colorectal cancer (CRC) risk, and whether these genetic factors, along with traditional risk factors, could contribute to the colorectal cancer risk prediction in a Chinese Han population.
  
  
  METHODS
  A case-control study (1 066 CRC cases and 3 880 controls) was initially conducted to assess the association between 21 recently discovered single-nucleotide polymorphisms (SNPs) and CRC risk. Genetic risk score (GRS) and weighted genetic risk score (wGRS) were calculated to evaluate the joint effects of selected loci. Multiple models combining genetic and non-genetic factors were established and receiver operating characteristic curve analysis was used to compare the discriminatory power of different predictive models.
  
  
  RESULTS
  There were 7 SNPs significantly associated with CRC susceptibility. As the GRS or wGRS increased, the risk of CRC also increased (trend P=0.002 6 for GRS, trend P<0.000 1 for wGRS). The ORs for highest versus lowest quartile of GRS and wGRS were 1.33 (95% CI: 1.12-1.58, P=0.001 0) and 1.76 (95% CI: 1.45-2.14, P<0.000 1) , respectively. The model incorporating wGRS and traditional risk factors, including sex, age, smoking and drinking, was the best one to predict CRC risk in this population, with an area under curve of 0.593 (95% CI: 0.573-0.613).
  
  
  CONCLUSIONS
  Multiple genetic loci identified by GWASs jointly influenced the CRC risk. The combination of genetic factors and conventional non-genetic factors improved the performance of risk predictive model for colorectal cancer.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Jiaoyuan
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Chang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Yajie
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Juntao
authors.initials: J
authors.lastname: Ke
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Jiao
authors.initials: J
authors.lastname: Lou
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhong
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health.
authors.forename: Jing
authors.initials: J
authors.lastname: Gong
authors.affiliation: Clinical Laboratory of the Fourth Affiliated Hospital, Zhejiang University School of Medicine; Email: xiaopingxia@sina.com.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xia
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health; Email: miaoxp@hust.edu.cn.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Miao
mesh_terms: D044466:Asian People; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D005006:Ethnicity; D056426:Genetic Loci; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D012372:ROC Curve; D012307:Risk Factors