TY - JOUR
T1 - Exogenous hormones and colorectal cancer risk in Canada
T2 - Associations stratified by clinically defined familial risk of cancer
AU - Campbell, Peter T.
AU - Newcomb, Polly
AU - Gallinger, Steven
AU - Cotterchio, Michelle
AU - McLaughlin, John R.
N1 - Funding Information:
Acknowledgments The authors thank Dr Elizabeth Dicks, Dr Darshana Daftary, Teresa Mulvenna, and staff and investigators of the Ontario and Newfoundland Colorectal Cancer Registries for their contributions to this project. PTC thanks Professors Anthony Hanley, Mary Chipman, Loraine Marrett, and Edward Giovannucci for helpful discussions of this work.This work was supported by the National Cancer Institute, National Institutes of Health under RFA # CA-96-011 and through cooperative agreements with members of the Colon Cancer Family Registry (CFR) and P.I.s. The content of this manuscript does not necessarily reflect the views or policies of the National Cancer Institute or any of the collaborating institutions or investigators in the Colon CFR, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government or the Colon CFR. Data collection in Newfoundland and Labrador was funded by the Canadian Institutes of Health Research (CRT 43821). PTC was partially supported by a National Cancer Institute of Canada Doctoral Fellowship (#13523) with funds from the Canadian Cancer Society.
PY - 2007/9
Y1 - 2007/9
N2 - Objective: This work assessed associations between colorectal cancer risk and postmenopausal/contraceptive hormones; subgroup analyses included women with a clinically defined family history of cancer. Methods: A population based case-control study of incident colorectal cancer was conducted among women aged 20-74 years in Ontario and Newfoundland & Labrador, Canada. Incident cases (n = 1,404) were selected from provincial cancer registries and controls (n = 1,203) were identified through property records, and other means, between January 1997 and April 2006. Family history of cancer, exogenous hormone-use, and other risk factors were collected via self-administered questionnaires. Multivariate unconditional logistic regression analyses were used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Results: Decreased risks of colorectal cancer were observed with ever-users of: hormonal contraceptives (OR: 0.77; CI: 0.65-0.91), estrogen-only postmenopausal hormones (OR: 0.60; CI: 0.47-0.75), and estrogen-progestin postmenopausal hormones (OR: 0.70; CI: 0.52-0.95). Risk estimates were similar between women with and without a strong familial history of cancer. Age at initiation of hormonal contraceptives was associated with colorectal cancer risk; women who initiated use at younger ages (age <22 years: OR: 0.60; CI: 0.47-0.77) experienced a greater reduced risk of disease than women who initiated use at later ages (age 30+: OR: 0.92; CI: 0.68-1.24; p trend: 0.0026). Conclusions: These results indicate that exogenous hormone-use is linked with reduced risk of colorectal cancer among women with a strong familial risk of cancer, consistent with observations on population samples of sporadic colorectal cancer cases. A potential age-effect for use of hormonal contraceptives warrants further attention.
AB - Objective: This work assessed associations between colorectal cancer risk and postmenopausal/contraceptive hormones; subgroup analyses included women with a clinically defined family history of cancer. Methods: A population based case-control study of incident colorectal cancer was conducted among women aged 20-74 years in Ontario and Newfoundland & Labrador, Canada. Incident cases (n = 1,404) were selected from provincial cancer registries and controls (n = 1,203) were identified through property records, and other means, between January 1997 and April 2006. Family history of cancer, exogenous hormone-use, and other risk factors were collected via self-administered questionnaires. Multivariate unconditional logistic regression analyses were used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Results: Decreased risks of colorectal cancer were observed with ever-users of: hormonal contraceptives (OR: 0.77; CI: 0.65-0.91), estrogen-only postmenopausal hormones (OR: 0.60; CI: 0.47-0.75), and estrogen-progestin postmenopausal hormones (OR: 0.70; CI: 0.52-0.95). Risk estimates were similar between women with and without a strong familial history of cancer. Age at initiation of hormonal contraceptives was associated with colorectal cancer risk; women who initiated use at younger ages (age <22 years: OR: 0.60; CI: 0.47-0.77) experienced a greater reduced risk of disease than women who initiated use at later ages (age 30+: OR: 0.92; CI: 0.68-1.24; p trend: 0.0026). Conclusions: These results indicate that exogenous hormone-use is linked with reduced risk of colorectal cancer among women with a strong familial risk of cancer, consistent with observations on population samples of sporadic colorectal cancer cases. A potential age-effect for use of hormonal contraceptives warrants further attention.
KW - Amsterdam criteria
KW - Bethesda criteria
KW - Colorectal cancer
KW - Contraceptives
KW - Family history of cancer
KW - HRT
KW - Postmenopausal hormones
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U2 - 10.1007/s10552-007-9015-7
DO - 10.1007/s10552-007-9015-7
M3 - Article
C2 - 17549595
AN - SCOPUS:34250877469
SN - 0957-5243
VL - 18
SP - 723
EP - 733
JO - Cancer Causes and Control
JF - Cancer Causes and Control
IS - 7
ER -