Abstract
B90
Different subtypes of ovarian cancer appear to have different causes yet few studies have examined the relation between body-size and weight and the various types of ovarian cancer. We therefore examined the associations between body mass index (BMI) and weight gain in adulthood and risk of the different histological subtypes of epithelial ovarian cancer in a national case-control study in Australia. Cases aged 18-79 years with a new diagnosis of invasive epithelial ovarian cancer (n=1269) or low malignant potential tumour (n=311) were identified through a network of clinics, physicians and state cancer registries throughout Australia. Controls (n=1509) were selected from the Commonwealth Electoral Roll. Height and weight one year prior to diagnosis for cases or prior to date of questionnaire completion for controls, at age 20 years and maximum weight, together with other risk factor information were ascertained by means of a self-administered questionnaire. Obesity (at one year prior) was associated with increased risk of invasive clear cell tumours (OR 2.3, 95% CI 1.2-4.2), serous tumours of the peritoneum (OR 2.9, 95% CI 1.7-4.9), and also borderline serous tumours (OR 1.8, 95% CI 1.1-2.8). Obesity was not associated with mucinous (invasive or borderline) or endometrioid tumours. Overweight (at one year prior) was associated with increased risk of serous tumours of the peritoneum (OR 2.2, 95% CI 1.3-3.6) and also serous tumours of the ovary and fallopian tube (premenopausal women only) (OR 2.4, 95% CI 1.4-4.3). There was no significant association with BMI at age 20 years, or weight gain for any of the histological subtypes, although there was a suggestion that the excess risk associated with high BMI at maximum lifetime weight was seen only for those women who remained obese one year prior to diagnosis. These results suggest that the association between BMI and epithelial ovarian cancer varies by histological subtype.
Sixth AACR International Conference on Frontiers in Cancer Prevention Research-- Dec 5-8, 2007; Philadelphia, PA