Physical activity and risk of colorectal cancer in men and women

Abstract

Summary We examined the association between self-reported occupational and recreational physical activity and the subsequent risk of colorectal cancer in a population-based cohort in Norway. During a mean follow-up time of 16.3 years for males and 15.5 years for females, 236 and 99 colon cancers and 170 and 58 rectal cancers were observed in males and females, respectively, among 53 242 males and 28 274 females who attended the screening between 1972 and 1978. Physical activity at a level equivalent to walking or bicycling for at least four hours a week during leisure-time was associated with decreased risk of colon cancer among females when compared with the sedentary group (RR=0.62, 95% CI 0.40-0.97). Reduced risk of colon cancer was particularly marked in the proximal colon (RR=0.51, 95% CI 0.28-0.93). This effect was not observed for occupational physical activity alone, probably due to a narrow range of self-reported physical activity at work among females. However, by combining occupational and recreational physical activity we observed an inverse dose-response effect as increasing total activity significantly reduced colon cancer risk (P for trend=0.04). Among males 45 years or older at entry to the study, an inverse dose-response effect was observed between total physical activity and colon cancer risk (P for trend = 0.04). We also found in males a stronger preventive effect for physical activity in the proximal as compared to distal colon. In addition, we found a borderline significant decrease in colon cancer risk for occupational physical activity in males 45 years or older when compared to the sedentary group (RR = 0.74, 95% CI 0.53-1.04). All results were adjusted for age, body mass index, serum cholesterol and geographic region. No association between physical activity and rectal cancer was observed in males or females. The protective effect of physical activity on colon cancer risk is discussed in regard to energy balance, dietary factors, age, social class, body mass index and gastrointestinal transit time.Keywords: physical activity; colorectal cancer; cohort study; gender differences; subsites Cancer of the large intestine is one of the most common neoplasms in western countries (Muir et al., 1987; Engeland et al., 1993). Recently, the role of exercise in the aetiology of colon carcinogenesis has drawn particular interest. A growing number of epidemiological studies have reported a protective effect of occupational physical activity on colon cancer risk (Garabrant et al., 1984;Gerhardsson et al., 1986;Brownson et al., 1989;Peters et al., 1989;Arbman et al., 1993; Chow et al., 1993;Fraser and Pearce, 1993). Others have observed that recreational physical activity protects against colon cancer (Wu et al., 1987;Slattery et al., 1988;Gerhardsson et al., 1988;Severson et al., 1989;Ballard-Barbash et al., 1990;Lee et al., 1991;Markowitz et al., 1992; Giovannuci et al., 1995). In contrast, the association between physical activity and risk of rectal cancer is more inconsistent (Vena et al., 1985;Ge...

Prospective study of colorectal cancer risk and physical activity, diabetes, blood glucose and BMI: exploring the hyperinsulinaemia hypothesis

“…Several cohort studies have shown that physical activity is negatively associated with colorectal cancer risk, and in accordance with our findings in men, a reduction of 40 to 50% has been reported (Wu et al, 1987;Lee et al, 1991;Giovannucci et al, 1995Giovannucci et al, , 1996Thune and Lund, 1996;Martinez et al, 1997). Two interpretations have been proposed for the reduced risk.…”

“…Contrary to some other studies, we found no significant association with physical activity among women (Thune and Lund, 1996;Martinez et al, 1997). We also explored the effect of extreme levels of physical activity in women, but this did not change the results.…”

Physical activity, sedentary behavior, and the risk of colon and rectal cancer in the NIH-AARP Diet and Health Study

“…Few cohort studies of physical activity and colon cancer have conducted analyses stratified by tumor sub-site [6,12,13,[16][17][18][32][33][34]36,37,48,49], with those that did yielding conflicting results. Some studies reported stronger inverse findings for the proximal colon [12,16,17,33,48], while others observed stronger inverse associations for distal colon sites [6,13,18,36,37]. Observed differences may be due to varying etiologies between tumors of the proximal and distal colon [50].…”

“…Results of the Fukuoka Colorectal Cancer Study showed that job-related as well as total and moderate leisure-time physical activity were associated with a significant reduction of rectal cancer risk in men only [51]. In contrast, several cohort studies [12,17,33] have failed to detect an association between physical activity and rectal cancer.…”

Physical Inactivity, Water Intake and Constipation as Risk Factors for Colorectal Cancer among Adults in Jordan

“…Many studies divided the physical activity into occupational and recreational (Thune and Lund, 1996;Marchand et al, 1997;Simons et al, 2013). Thune and Lund (1996) and Marchand et al (1997) documented that both occupational and recreational physical activities were inversely associated with colon cancer risk.…”