Occupational and leisure-time physical activity and risk of colon cancer by subsite.
OBJECTIVE
Studies of physical activity and colon cancer risk by anatomic site have provided inconsistent results.


METHODS
We analyzed data from a population-based case-control study conducted in Iowa involving 685 colon cancer cases and 2434 control subjects.


RESULTS
Among those who reported recreational activity more than twice per week, a 30% risk reduction of colon cancer was observed for all sites with a 40% risk reduction for cancer of the right colon. Occupational physical activity was also associated with a reduced risk of colon cancer. The risk was the lowest for those with both high occupational and recreational physical activity (odds ratio, 0.5; 95% confidence interval, 0.3-0.8).


CONCLUSIONS
Increased physical activity was inversely associated with colon cancer risk. The inverse associations were stronger for the right than for the left colon.
Yale University School of Public Health, New Haven, Connecticut, USA.
Yawei
Y
Zhang
Kenneth P
KP
Cantor
Mustafa
M
Dosemeci
Charles F
CF
Lynch
Yong
Y
Zhu
Tongzhang
T
Zheng
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000453:epidemiology*; D015444:Exercise; D005260:Female; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D009790:Occupations; D012306:Risk