There were no significant differences between the two hospital control groups with respect to food groups, total energy intake and other variables, with the exception of dairy products and vegetable oil (which had little association with ovarian cancer risk). The mean intakes of food groups by the community controls were also similar but they consumed less salted vegetables and animal fat than the hospital controls. Data from all three control groups were then combined to form a single control group in subsequent analyses. Results from recent patients and all cases were also similar (data not provided for brevity but were available upon request). Therefore, we report the combined results of all cases below.
There were no differences in mean age at interview, locality (urban or rural areas), education, BMI (5 years ago), smoking, alcohol consumption, marital and menopause status, and tubal ligation between cases and controls. Compared to controls, patients with epithelial ovarian cancer tended to have a higher family income, less oral contraceptive use, lower parities, and less physical activity. More of them had apparent family susceptibility. contrasts the sample characteristics of women with and without ovarian cancer.
Characteristics of Chinese women with and without ovarian cancer
gives the odds ratios of ovarian cancer according to intake quartile of food groups, together with results of linear trend tests for the corresponding continuous variables. The risk tended to decline with increasing consumption of vegetables and fruits. Intakes of animal fat and preserved vegetables were associated with an elevated risk of ovarian cancer. The adjusted OR's of the upper quartile, relative to the lower quartile, were 0.24 for vegetables, 0.36 for fruits, 4.6 for animal fat and 3.4 for preserved vegetables, with significant dose-response relationships. Higher intakes of fresh meat appeared to be positively associated with ovarian cancer, whereas the intake of staple foods seemed to offer some protection, but both chi-square tests of linear trend were insignificant. Among the subgroups of vegetables, the estimated OR's were 0.38 for allium vegetables and 0.4 for soybean products. No significant association was evident with respect to preserved animal foods, fresh fish, poultry, eggs, dairy products and plant oil.
Adjusted odds ratiosa (95% confidence interval) of epithelial ovarian cancer for intake quartilesb of food groups with cut-points (kg per year)
gives the OR for eating habits, the frequency of which were also subjected to linear trend testing. The risk of ovarian cancer appeared to increase with preference to fat, fried, cured and smoked foods. The estimated OR's of frequent intake compared to the never/seldom category were 1.96 for fat, 2.50 for fried food, 4.46 for cured food and 9.60 for smoked food, with all the corresponding trends being significant at the 5% level.
Adjusted odds ratiosa (95% confidence interval) of epithelial ovarian cancer for eating habitsb