Physical activity and the risk of ovarian cancer: A case‐control study in Canada

Abstract

We evaluated the impact of recreational and occupational physical activity on ovarian cancer risk using data from a population-based case-control study of 442 cases with histologically confirmed incident ovarian cancer and 2,135 controls aged 20-76 years, conducted in 1994-1997 in Canada. Frequency and intensity of physical activity were collected through self-administered questionnaires. Compared to women in the lowest tertiles of moderate, vigorous and total recreational activity, those in the highest tertiles had multivariable-adjusted odds ratios (and 95% confidence intervals) of 0.67 (0.50-0.88), 0.93 (0.70-1.24) and 0.73 (0.58-0.98), respectively. There were statistically significant trends of decreasing risk with increasing levels of moderate and total recreational activity, with similar patterns for premenopausal and postmenopausal women. A significant reduction in risk associated with higher level of moderate recreational activity was observed for serous, endometrioid and other but not mucinous types of tumors. The analyses in one province with the largest number of cases and controls indicated that occupational activity was associated with reduced ovarian cancer risk by lifetime activity and by various life periods (early 20s, early 30s, early 50s and 2 years before interview). Our study suggests that occupational and regular moderate recreational physical activity reduce ovarian cancer risk. ' 2005 Wiley-Liss, Inc.Key words: case-control studies; exercise; ovarian neoplasms; occupation; recreation Although the evidence for a protective effect of physical activity on colon and breast cancer is convincing, the evidence for an inverse association between physical activity and ovarian cancer is insufficient. 1,2 If proven to reduce ovarian cancer risk, physical activity-a modifiable lifestyle factor-could provide a method to prevent this fourth most common neoplasm in women, which has a poor prognosis.The influence of physical activity on ovarian cancer risk was examined in 10 studies with inconsistent results. [3][4][5][6][7][8][9][10][11][12] Five studies suggested a decreased risk of ovarian cancer with high levels of physical activity, 3-7 3 found no association, [8][9][10] and 2 observed a positive association. 11,12 The discrepancy could be due to the fact that different studies assessed different parameters (including type, frequency, duration, intensity) of physical activity in populations with different profiles.Using data from the Canadian National Enhanced Cancer Surveillance System (NECSS), which collected detailed information on recreational physical activity, occupational physical activity (in 1 province) and other risk factors for cancers, we further evaluated the relation of physical activity to ovarian cancer risk. Material and methods Study populationThe NECSS was a multicomponent, collaborative project of Health Canada and the provincial cancer registries. The case-control component included individual data from 21,020 Canadians with 1 of 19 types of cancers and 5,039 population contro...

Physical Activity and Cancer

“…In contrast to the finding that physical activity has a stronger protective effect against breast cancer in lean than overweight women, Pan et al (2005) observed the reverse with regards to ovarian cancer risk, in that a stronger effect was identified in overweight and obese, compared to lean, women. It may be that overweight and obesity exert a stronger influence on ovarian cancer than on breast cancer.…”

Prospective study of physical activity in different periods of life and the risk of ovarian cancer

“…11 As summarized in Table I, the results of case-control studies have been inconclusive as well. [12][13][14][15][16][17][18][19] We studied the association between physical activity and ovarian cancer incidence over an average of 11 years of follow-up in the large, population-based prospective Women's Lifestyle and Health Study. From the biological effects described earlier, we hypothesized that moderate to high levels of physical activity would protect against ovarian cancer.…”

Recreational Physical Activity and Risk of Ovarian Cancer: a Meta-analysis

“…Among the left 24 studies, 18 literatures (5 the interested exposure was not RPA; 1 was duplication, 12 evaluation of RPA was not MET-hr/week) were excluded according to the inclusion and exclusion criteria. As a result, 6 literatures were included in this meta-analysis (Bertone et al, 2001;Bertone et al, 2002;Pan et al, 2005;Patel et al, 2006;Lahmann et al, 2009;Rossing et al, 2010).…”

“…The 6 included articles were 3 prospective cohort studies (Bertone et al, 2001;Patel et al, 2006;Lahmann et al, 2009) and 3 case control studies (Bertone et al, 2002;Pan et al, 2005;Rossing et al, 2010). Four researches were conducted in American (Bertone et al, 2001;Patel et al, 2006;Rossing et al, 2010).…”

“…Four researches were conducted in American (Bertone et al, 2001;Patel et al, 2006;Rossing et al, 2010). The other two studies were conducted in European (Lahmann et al, 2009) and Canada (Pan et al, 2005), respectively. A total of 435398 participants including 2983 OC patients were included in this meta-analysis.…”