Background/Objectives: There is strong evidence that a proportion of cancer cases are related to a combination of modifiable risk factors. The prevalence of obesity-related cancers (ORC) has risen sharply in recent decades, representing a major public health challenge. Our aim was to assess the association between adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations and the incidence of ORCs in the "Seguimiento Universidad de Navarra" (SUN) cohort.

Methods: Data from 18,446 participants in the SUN cohort were analyzed. An 8-item score was constructed to measure adherence to the 2018 WCRF/AICR recommendations at baseline, including body mass index, physical activity, consumption of fruits/vegetables and dietary fiber, “fast-food”, red and processed meat, sugar-sweetened beverages, alcohol intake and breastfeeding to build a 0 to 7 score (subsequently categorized in 3 groups: 0 to 3, > 3 to 5, and > 5).

Results: Over a median of 13 years of follow up, 269 incidence ORC cases were confirmed. An inverse significant association was observed for both the continuous (hazard ratio [HR] 0.75, 95% confidence interval [CI]: 0.65-0.88, p value ≤ 0.001 per each additional item in the 0-to-8 score) and categorized (HR > 5 vs. 0-to-3 points 0.66, 95%CI: 0.44-0.99, p trend = 0.035) scores, after multivariate adjustments. Adherence was very low for specific components, including limiting processed and red meat (1.5%), fiber intake (18.1%), and alcohol consumption (20.7%).

Conclusions/Recommendations: In the SUN cohort, higher adherence to the 2018 WCRF/AICR recommendations was associated with a reduced risk of ORC, underscoring their potential for ORC prevention despite the generally low adherence observed.

Funding: el Proyecto SUN ha recibido financiación del Gobierno de España-Instituto de Salud Carlos III y del Fondo Europeo de Desarrollo Regional (FEDER) (RD 06/0045, CIBER-OBN, ayudas PI10/02658, PI10/02293, PI13/00615, PI14/01668, PI14/01798, PI14/01764, PI17/01795, PI20/00564, PI23/01332, G03/140), del Gobierno de Navarra (27/2011, 45/2011, 122/2014), del Plan Nacional sobre Drogas (2020/021) y de la Universidad de Navarra. Ninguna de las entidades financiadoras participó en el diseño, el análisis o la redacción del presente artículo, ni impuso restricciones a su publicación.