TY - JOUR
T1 - Reproductive and menstrual factors and colorectal cancer incidence in the Women's Health Initiative Observational Study
AU - Murphy, Neil
AU - Xu, Linzhi
AU - Zervoudakis, Alice
AU - Xue, Xiaonan
AU - Kabat, Geoffrey
AU - Rohan, Thomas E.
AU - Wassertheil-Smoller, Sylvia
AU - O'Sullivan, Mary Jo
AU - Thomson, Cynthia
AU - Messina, Catherine
AU - Strickler, Howard D.
AU - Gunter, Marc J.
N1 - Funding Information:
National Institutes of Health, National Heart Lung and Blood Institute, contract number HHSN268200900010C (to PI, MG). The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, US Department of Health and Human Services through contracts HHSN268201100046C, HHSN268201600003C, HHSN268201600002C, HHSN26820160 0004C, HHSN268201600001C and HHSN271201100004C. WHI Investigators: Program Office: National Heart, Lung, and Blood Institute, Bethesda, MD, USA: Jacques Rossouw, Shari Ludlam, Dale Burwen, Joan McGowan, Leslie Ford and Nancy Geller. Clinical Coordinating Center: Fred Hutchinson Cancer Research Center, Seattle, WA, USA: Garnet Anderson, Ross Prentice, Andrea LaCroix and Charles Kooperberg. Investigators and Academic Centers: Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA: JoAnn E Manson; MedStar Health Research Institute/Howard University, Washington, DC, USA: Barbara V Howard; Stanford Prevention Research Center, Stanford, CA, USA: Marcia L Stefanick; The Ohio State University, Columbus, OH, USA: Rebecca Jackson; University of Arizona, Tucson/Phoenix, AZ, USA: Cynthia A Thomson; University at Buffalo, Buffalo, NY, USA: Jean Wactawski-Wende; University of Florida, Gainesville/Jacksonville, FL, USA: Marian Limacher; University of Iowa, Iowa City/Davenport, IA, USA: Robert Wallace; University of Pittsburgh, Pittsburgh, PA, USA: Lewis Kuller; Wake Forest University School of Medicine, Winston-Salem, NC, USA: Sally Shumaker
Publisher Copyright:
© 2017 Cancer Research UK. All rights reserved.
PY - 2017/1/3
Y1 - 2017/1/3
N2 - Background:Reproductive and menstrual factors have been evaluated as surrogates for long-term hormonal exposures in several prospective studies of colorectal cancer, yet findings have been conflicting.Methods:The relation of reproductive and menstrual factors (self-reported via a reproductive history questionnaire) with incident colorectal cancer was investigated among women enrolled in the Women's Health Initiative Observational Study (WHI-OS), a longitudinal cohort of 93 676 postmenopausal women (aged 50-79 years at enrolment) in which 1149 incident cases of colorectal cancer occurred over a median follow-up of 11.9 years. Multivariable Cox proportional hazards models that included established colorectal cancer risk factors were constructed to examine the association of colorectal cancer incidence with reproductive and menstrual factors.Results:Having had two children (vs nulliparous: hazard ratio (HR)=0.80, 95% confidence interval (CI): 0.64-0.99) was inversely associated with colorectal cancer risk. Compared with never users, ever use of oral contraceptives was associated with lower colorectal cancer risk (HR=0.74, 95% CI: 0.63-0.86); however, no relationship was observed for duration of oral contraceptives use (4 years vs 1 year: HR=0.94, 95% CI: 0.67-1.32). None of the remaining reproductive and menstrual factors was associated with colorectal cancer incidence.Conclusions:Parity and prior use of oral contraceptives were associated with lower colorectal cancer risk in this cohort of postmenopausal women.
AB - Background:Reproductive and menstrual factors have been evaluated as surrogates for long-term hormonal exposures in several prospective studies of colorectal cancer, yet findings have been conflicting.Methods:The relation of reproductive and menstrual factors (self-reported via a reproductive history questionnaire) with incident colorectal cancer was investigated among women enrolled in the Women's Health Initiative Observational Study (WHI-OS), a longitudinal cohort of 93 676 postmenopausal women (aged 50-79 years at enrolment) in which 1149 incident cases of colorectal cancer occurred over a median follow-up of 11.9 years. Multivariable Cox proportional hazards models that included established colorectal cancer risk factors were constructed to examine the association of colorectal cancer incidence with reproductive and menstrual factors.Results:Having had two children (vs nulliparous: hazard ratio (HR)=0.80, 95% confidence interval (CI): 0.64-0.99) was inversely associated with colorectal cancer risk. Compared with never users, ever use of oral contraceptives was associated with lower colorectal cancer risk (HR=0.74, 95% CI: 0.63-0.86); however, no relationship was observed for duration of oral contraceptives use (4 years vs 1 year: HR=0.94, 95% CI: 0.67-1.32). None of the remaining reproductive and menstrual factors was associated with colorectal cancer incidence.Conclusions:Parity and prior use of oral contraceptives were associated with lower colorectal cancer risk in this cohort of postmenopausal women.
UR - http://www.scopus.com/inward/record.url?scp=85000786012&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85000786012&partnerID=8YFLogxK
U2 - 10.1038/bjc.2016.345
DO - 10.1038/bjc.2016.345
M3 - Article
C2 - 27898658
AN - SCOPUS:85000786012
SN - 0007-0920
VL - 116
SP - 117
EP - 125
JO - British Journal of Cancer
JF - British Journal of Cancer
IS - 1
ER -
