Abstract PD11-01: Adherence to the new WCRF cancer prevention recommendations associates with a decreased breast cancer risk

Abstract Background: Breast cancer remains the leading cancer in women. In 2018, following its summary report, the World Cancer Research Fund (WCRF) issued its recommendations for cancer prevention based on the nutritional risk factors with a sufficient level of evidence, several of which being related to breast cancer. Our objective was to study whether adherence to these new recommendations was actually associated with reduced risk of breast cancer. Methods: A total of 62,546 women from the NutriNet-Santé population-based cohort study (2009-2019) were included in our analyses. Adherence to the 2018 WCRF recommendations was assessed using the operationalized score on a 7-point scale, proposed by Shams-White et al (Nutrients 2019), including: weight, physical activity, fruit and vegetables, dietary fibers, ultra-processed foods, red and processed meat, sugary drinks and alcohol. Usual dietary intakes were assessed using repeated 24h-dietary records and physical activity level using the IPAQ questionnaire. Cox proportional hazard models were computed with adjustment for the following potential confounders: educational level, height, smoking status, number of 24h dietary records, family history of cancer, number of biological children, age at menarche, age at parity, menopausal status, use of oral contraception or hormonal treatment for menopause. Results: During a median follow-up of 7.3 years, 745 women were diagnosed with a first incident breast cancer. The median WCRF 2018 adherence score was 3.75 (IQR: 3.25-4.50). An increase of 1-point increment in the score was associated with a decreased risk of breast cancer (HR=0.92; 95%CI 0.85-1.00; P=0.05), and especially of breast cancer post-menopause (n=456 cases, HR=0.88; 0.79-0.98; P=0.02). No association was observed for breast cancer pre-menopause (n=289, HR=0.99; 0.87-1.12; P=0.8). Sugary drink, alcohol and weight components of the score particularly contributed to the observed association. Conclusions: Our results suggest that a higher adherence to the WCRF 2018 recommendations for cancer prevention is associated to a decreased risk of breast cancer. Considering that the WCRF cancer recommendations are consistent with overall food-based dietary guidelines, such recommendations should be promoted to the general public and transposed as public health actions to contribute to decrease the burden of cancer. Citation Format: Mélanie Deschasaux, Laurent Bourhis, Laurent Zelek, Eloi Chazelas, Charlotte Debras, Serge Hercberg, Paule Latino-Martel, Chantal Julia, Emmanuelle Kesse-Guyot, Bernard Srour, Mathilde Touvier. Adherence to the new WCRF cancer prevention recommendations associates with a decreased breast cancer risk [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD11-01.