Manisha Pahwa1, M Anne Harris2, Jill MacLeod3, Michael Tjepkema4, Paul A Peters5, Paul A Demers6. 1. Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, Ontario M5G 2L3, Canada. Electronic address: manisha.pahwa@occupationalcancer.ca. 2. Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, Ontario M5G 2L3, Canada; School of Occupational and Public Health, Ryerson University, 350 Victoria Street, POD 249, Toronto, Ontario M5B 2K3, Canada; Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, Ontario M5T 3M7, Canada. 3. Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, Ontario M5G 2L3, Canada. 4. Health Analysis Division, Statistics Canada, 150 Tunney's Pasture Driveway, Ottawa, Ontario K1A 0T6, Canada. 5. Departments of Sociology and Economics, University of New Brunswick Fredericton Campus, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada. 6. Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, Ontario M5G 2L3, Canada; Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, Ontario M5T 3M7, Canada; CAREX Canada, Faculty of Health Sciences, Blusson Hall 11300, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
Abstract
BACKGROUND: Sedentary behaviour is a potential risk factor for colorectal cancer. We examined the association between sedentary work, based on body position, and colorectal cancer risk in Canadians. METHODS: A working body position category (a. sitting; b. standing and walking; c. sitting, standing, and walking; d. other) was assigned to occupations reported by 1991 Canadian Census respondents based on national occupational counselling guidelines. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) were estimated for cancers of the colon (overall, proximal, and distal) and rectum in men and women newly diagnosed from 1992 to 2010. RESULTS: Compared to "sitting" jobs, men in occupations with "other" (non-sitting, -standing, or -walking) body positions had a weakly significant reduced colon cancer risk (HR=0.93, 95% CI: 0.89, 0.98) primarily attributed to protection at the distal site (HR=0.90, 95% CI: 0.84, 0.97). Men in "standing and walking" and "sitting, standing, and walking" jobs did not have significantly reduced colon cancer risks. No effects were observed for rectal cancer in men or colon and rectal cancer in women. CONCLUSION: The two significant findings of this analysis should be followed-up in further investigations with additional information on potential confounders. Null findings for rectal cancer were consistent with other studies.
BACKGROUND: Sedentary behaviour is a potential risk factor for colorectal cancer. We examined the association between sedentary work, based on body position, and colorectal cancer risk in Canadians. METHODS: A working body position category (a. sitting; b. standing and walking; c. sitting, standing, and walking; d. other) was assigned to occupations reported by 1991 Canadian Census respondents based on national occupational counselling guidelines. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) were estimated for cancers of the colon (overall, proximal, and distal) and rectum in men and women newly diagnosed from 1992 to 2010. RESULTS: Compared to "sitting" jobs, men in occupations with "other" (non-sitting, -standing, or -walking) body positions had a weakly significant reduced colon cancer risk (HR=0.93, 95% CI: 0.89, 0.98) primarily attributed to protection at the distal site (HR=0.90, 95% CI: 0.84, 0.97). Men in "standing and walking" and "sitting, standing, and walking" jobs did not have significantly reduced colon cancer risks. No effects were observed for rectal cancer in men or colon and rectal cancer in women. CONCLUSION: The two significant findings of this analysis should be followed-up in further investigations with additional information on potential confounders. Null findings for rectal cancer were consistent with other studies.
Authors: Madar Talibov; Jorma Sormunen; Elisabete Weiderpass; Kristina Kjaerheim; Jan-Ivar Martinsen; Per Sparen; Laufey Tryggvadottir; Johnni Hansen; Eero Pukkala Journal: Saf Health Work Date: 2019-01-09