Grant Details
Grant Number: |
5R01CA078698-02 Interpret this number |
Primary Investigator: |
Collet, Jean Paul |
Organization: |
Sir Mortimer B. Davis Jewish Gen Hosp |
Project Title: |
Hormonal Replacement Therapy and Risk of Colon Cancer |
Fiscal Year: |
1999 |
Abstract
DESCRIPTION: Colorectal cancer is the third most frequent cancer and the
second cause of cancer mortality in women in the Western World. Although
the mechanism has not been confirmed, epidemiological studies and some
evidence from animal studies suggest that reproductive hormones,
specifically estrogens, may protect against the development of colon
cancer in post-menopausal women. This historical population-based nested
case-control study will investigate the effect of past exposure to
hormonal replacement therapy (HRT) on the risk of developing colon cancer.
Methods: The source population for the study will be the dynamic cohort
defined by membership in the Saskatchewan Prescription Drug Plan (SPDP).
Incident cases of colon cancer over 50 years of age will be accrued by the
provincial cancer registry from 1981 to 98 (n=2,400). Four age-matched
controls per case will be selected from the source population, using
incidence density sampling. Detailed prescription drug exposure data on
HRT over a minimum of 5 years before diagnosis and up to a maximum 20
years will be obtained from the SPDP. Also obtained from the SPDP for this
same time period will be prescription information on oral contraceptives
and NSAIDs. Data on potential confounders will be obtained from a sample
of the subjects accrued from January 1, 1994 to December 31, 1998 by means
of telephone interviews carried out blind to disease status. The sampling
fractions will vary according to disease and drug exposure status, so that
the second stage sample will contain about 150 exposed cases and controls
and 150 unexposed cases and controls (total=500-650 subjects). Confounding
will be controlled and effect modification will be studied with logistic
regression, using appropriate correction for the second stage-sampling
scheme.
Significance: The applicant is in a unique position to examine the
respective effect of dose, duration and timing of HRT exposure on the risk
of developing colon cancer, for a period of time as far back as 20 years
prior to the index data. The findings will elaborate on the risk/benefit
profile of HRT, which will assist women and their physicians to make
informed decisions. In addition the results will be of value in the
development of comprehensive practice guidelines for HRT.
Publications
Two-stage Case-control Studies: Precision Of Parameter Estimates And Considerations In Selecting Sample Size
Authors: Hanley J.A.
, Csizmadi I.
, Collet J.P.
.
Source: American Journal Of Epidemiology, 2005-12-15 00:00:00.0; 162(12), p. 1225-34.
PMID: 16269581
Related Citations
Defining Hormone Replacement Therapy In Longitudinal Studies: Impact On Measures Of Effect
Authors: Csizmadi I.
, Collet J.P.
, Benedetti A.
, Boivin J.F.
, Hanley J.A.
.
Source: Pharmacoepidemiology And Drug Safety, 2004 Apr; 13(4), p. 215-25.
PMID: 15255088
Related Citations
Health-related Behavior And The Use Of Hormone Replacement Therapy
Authors: Csizmadi I.
, Collet J.P.
, Boivin J.F.
, Hanley J.A.
, Benedetti A.
.
Source: Pharmacoepidemiology And Drug Safety, 2004 Feb; 13(2), p. 65-71.
PMID: 14998067
Related Citations
The Effects Of Transdermal And Oral Oestrogen Replacement Therapy On Colorectal Cancer Risk In Postmenopausal Women
Authors: Csizmadi I.
, Collet J.P.
, Benedetti A.
, Boivin J.F.
, Hanley J.A.
.
Source: British Journal Of Cancer, 2004-01-12 00:00:00.0; 90(1), p. 76-81.
PMID: 14710210
Related Citations
Use Of Postmenopausal Estrogen Replacement Therapy From 1981 To 1997
Authors: Csizmadi I.
, Benedetti A.
, Boivin J.F.
, Hanley J.A.
, Collet J.P.
.
Source: Cmaj : Canadian Medical Association Journal = Journal De L'association Medicale Canadienne, 2002-01-22 00:00:00.0; 166(2), p. 187-8.
PMID: 11826941
Related Citations