Body fatness, physical activity and the risk of cervical cancer: Results from the EPIC cohort

Background: Obesity is a recognized risk factor for several types of cancer, while being physically active is known to reduce cancer risk. However, evidence for both remains inconclusive for cervical cancer. We evaluated the associations between body fatness and physical activity and the risk of invasive cervical cancer (ICC) within the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. Methods: This analysis included 293,523 women who completed lifestyle questionnaires and provided serum samples at baseline. The anthropometric indicators assessed were Body Mass Index (BMI), “a body shape index” (ABSI), waist circumference and waist-to-hip ratio. Physical activity was evaluated using a combined index of total physical activity (occupational, household and recreational activities), an index of physical activity determined in a Cambridge validation study (occupational and recreational activities excluding walking), and a specific recreational activity variable (walking, cycling, sports). Over a median follow-up of 15 years, 369 incident ICC cases were reported. In a nested case-control study, serum from 171 cases and 342 matched controls were tested for L1 antibodies against Human Papillomavirus (HPV) types 11, 16, 18, 31, 33, 35, 45, 52, 58, Chlamydia trachomatis and Human herpesvirus 2. Multivariable Cox and conditional regression models adjusted for potential confounders were performed. Results: Women with BMI over 30 kg/m2 had a nonsignificant increased risk of ICC (Hazard Ratio (HR)=1.19, 95%CI: 0.87-1.65) compared to women with BMI between 18.5-24.9 kg/m2. Women engaging occupational, household and recreational activities had a reduced risk of ICC (HR=0.74, 95%CI: 0.55-0.99) compared to being inactive. Sensitivity analysis incorporating HPV serology yielded similar results. Conclusions: These findings support the potential protective effect of physical activity against ICC, though the evidence for anthropometric measures remains inconclusive. Article category : Research article – Cancer Epidemiology