A literature scanning and prioritization framework to guide future systematic reviews for World Cancer Research Fund International's Global Cancer Update Programme

BackgroundThe 2018 World Cancer Research Fund (WCRF)/American Institute for Cancer Research Third Expert Report (TER) on diet, adiposity, physical activity and risk of 19 cancers could be enhanced with new data. A framework is needed to prioritize future systematic reviews. MethodsWe searched PubMed (January 2019-February 2024) for meta-analyses, pooled analyses, randomized controlled trials (RCTs), Mendelian randomization (MR) studies, and large (>100,000 participants) cohort studies. We assessed TER findings using conditional power (CP) and fail-safe number (FSN) statistics. We developed an exposure-based prioritization score (PS) by awarding or subtracting points considering the quantity, statistical significance, direction, and novelty of associations. ResultsWe compared 366 meta-analyses, 121 pooled analyses, 19 RCTs, 174 MR studies, and 391 cohort studies covering 151 exposures and 28 cancers with 1,371 TER meta-analyses. Based on CP, non-significant TER associations likely to become significant with additional evidence included folate and colorectal, waist circumference and lung, total fat and ovarian, tea and ovarian, and red meat and kidney cancers. The FSN indicated that most significant TER associations are unlikely to change with additional evidence. The median PS was 6 (range: -15 to 163), with top scores observed for anthropometric measurements (PSheight=40 to PSBMI=163), physical activity (PS=100), sedentary behavior (PS=64), alcohol (PS=52), tea (PS=36), dietary fiber (PS=31), milk/dairy (PS=29), micronutrients (PSretinol=27 to PSiron=38), vitamins (PSB12=22 to PSvitD=91), soy (PS=24), isoflavones (PS=23), and sugar-sweetened beverages (PS=22). Conclusions and ImpactThe prioritization framework can help identify impactful systematic reviews to complement TER conclusions and enhance our understanding of emerging research.