title: Incidence of colorectal cancer in BRCA1 and BRCA2 mutation carriers: results from a follow-up study.
abstract: BACKGROUND
  The BRCA1 and BRCA2 genes confer increased susceptibility to breast and ovarian cancer and to a spectrum of other cancers. There is controversy regarding the risk of colorectal cancer conferred by germline mutations in these two genes.
  
  
  METHODS
  We followed 7015 women with a BRCA mutation for new cases of colorectal cancer. Incidence rates in carriers were compared with population-specific incidence rates, and standardised incidence ratios (SIRs) were estimated. The expected numbers of cancers were computed by multiplying person-years at risk by the appropriate age-, sex- and country-specific incidence rates from the five countries.
  
  
  RESULTS
  Twenty-one incident colorectal cancer cases were observed among all mutation carriers, compared with 23.6 cases expected. The SIR for BRCA1 carriers was 0.92 (95% confidence interval (CI), 0.54-1.40, P=0.7) and for BRCA2 carriers was 0.82 (95% CI, 0.30-1.81, P=0.7). The SIR for colon cancer was 3.81 (95% CI 1.77-7.23) for women below the age of 50 years (both genes combined) and was 0.60 (95% CI 0.33-1.00) for women aged 50 years and above.
  
  
  CONCLUSIONS
  The risk of colorectal cancer is increased in female carriers of BRCA1 mutations below the age of 50 years but not in women with BRCA2 mutations or in older women.
authors.affiliation: Department of Cancer Epidemiology, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, FL 33647, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Phelan
authors.affiliation: Familial Breast Cancer Research, Women's College Research Institute, 790 Bay Street, Toronto, Ontario M5G 1N8, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Iqbal
authors.affiliation: Department of Preventive Medicine and Public Health, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Lynch
authors.affiliation: International Hereditary Cancer Center, Pomeranian Medical University, Al. Powstancow Wlpk. 72, 70-111 Szczecin, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Lubinski
authors.affiliation: International Hereditary Cancer Center, Pomeranian Medical University, Al. Powstancow Wlpk. 72, 70-111 Szczecin, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Gronwald
authors.affiliation: Norwegian Radium Hospital N-0310, Oslo, Norway.
authors.forename: P
authors.initials: P
authors.lastname: Moller
authors.affiliation: Epidemiology Research Unit, Research Centre of the University of Montreal Hospital Centre (CRCHUM), 3850 Street, Urbain, Montreal, Quebec H2W 1T8, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Ghadirian
authors.affiliation: Program in Cancer Genetics, Department of Oncology, McGill University, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4, Canada.
authors.forename: W D
authors.initials: WD
authors.lastname: Foulkes
authors.affiliation: Department of Obstetrics and Gynecology, University of Toronto and Gynecologic Oncology, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Armel
authors.affiliation: Sunnybrook Regional Cancer Centre, Toronto, Ontario M4N 3M5, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Eisen
authors.affiliation: Department of Population Sciences, Beckmann Research Institute, City of Hope, Duarte, CA 91010, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Neuhausen
authors.affiliation: Division of Human Genetics, The Ohio State University Medical Center, Comprehensive Cancer Center, Columbus, OH 43210, USA.
authors.forename: L
authors.initials: L
authors.lastname: Senter
authors.affiliation: Department of Obstetrics and Gynecology and Comprehensive Cancer Center, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
authors.forename: C F
authors.initials: CF
authors.lastname: Singer
authors.affiliation: London Regional Cancer Program, London, Ontario N6A 4L6, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Ainsworth
authors.affiliation: BC Cancer Agency, 675 West 10th Avenue, Vancouver, BC V5Z 1L3, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Kim-Sing
authors.affiliation: Beth Israel Deaconess Medical Center, Cancer Risk and Prevention Program, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: N
authors.initials: N
authors.lastname: Tung
authors.affiliation: Familial Breast Cancer Research, Women's College Research Institute, 790 Bay Street, Toronto, Ontario M5G 1N8, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Llacuachaqui
authors.affiliation: Department of Cancer Epidemiology, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, FL 33647, USA.
authors.forename: G
authors.initials: G
authors.lastname: Chornokur
authors.affiliation: Familial Breast Cancer Research, Women's College Research Institute, 790 Bay Street, Toronto, Ontario M5G 1N8, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Ping
authors.affiliation: Familial Breast Cancer Research, Women's College Research Institute, 790 Bay Street, Toronto, Ontario M5G 1N8, Canada.
authors.forename: S A
authors.initials: SA
authors.lastname: Narod
mesh_terms: D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein / Q000235:genetics*; D002170:Canada / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics*; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D012306:Risk; D014481:United States / Q000453:epidemiology
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human