Objective: Whether adiposity and lack of physical activity affect the risk for developing meningioma and glioma is poorly understood. Our objective was to characterize these associations in detail. Methods: We conducted a systematic review and meta-analysis of adiposity and physical activity in relation to meningioma and glioma using cohort and case-control studies published through February 2015. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: We identified 12 eligible studies of body mass index (BMI) and 6 studies of physical activity, comprising up to 2,982 meningioma cases and 3,057 glioma cases. Using normal weight as the reference group, overweight (summary relative risk [RR] = 1.21, 95% confidence interval [CI] = 1.01–1.43) and obesity (RR = 1.54, 95% CI = 1.32–1.79) were associated with increased risk of meningioma. In contrast, overweight (RR = 1.06, 95% CI = 0.94–1.20) and obesity (RR = 1.11, 95% CI = 0.98–1.27) were unrelated to glioma. Similarly, dose-response meta-analyses revealed a statistically significant positive association of BMI with meningioma, but not glioma. High vs low physical activity levels showed a modest inverse relation to meningioma (RR = 0.73, 95% CI = 0.61–0.88) and a weak inverse association with glioma (RR = 0.86, 95% CI = 0.76–0.97). Relations persisted when the data were restricted to prospective studies, except for the association between physical activity and glioma, which was rendered statistically nonsignificant (RR = 0.91, 95% CI = 0.77–1.07). Conclusions: Adiposity is related to enhanced risk for meningioma but is unassociated with risk for glioma. Based on a limited body of evidence, physical activity is related to decreased risk of meningioma but shows little association with risk of glioma.
10 December 2019 in American Journal of Gastroenterology
OBJECTIVE: Fecal immunochemical tests (FITs) detect the majority of colorectal cancers (CRCs), but evidence for variation in sensitivity according to the CRC stage is sparse and has not yet been systematically synthesized. Thus, our objective was to systematically review and summarize evidence on the stage-specific sensitivity of FITs. METHODS: We screened PubMed, Web of Science, Embase, and the Cochrane Library from inception to June 14, 2019, for English-language articles reporting on the stage-specific sensitivity of FIT for CRC detection using colonoscopy as a reference standard. Studies reporting stage-specific sensitivities and the specificity of FIT for CRC detection were included. Summary estimates of sensitivity according to the CRC stage and study setting (screening cohorts, symptomatic/diagnostic cohorts, and case-control studies) were derived from bivariate meta-analysis. RESULTS: Forty-four studies (92,447 participants including 3,034 CRC cases) were included. Pooled stage-specific sensitivities were overall very similar but suffered from high levels of imprecision because of small case numbers when calculated separately for screening cohorts, symptomatic/diagnostic cohorts, and case-control studies. Pooled sensitivities (95% confidence intervals) for all studies combined were 73% (65%–79%) for stage-I-CRCs and 80% (74%–84%), 82% (77%–87%), and 79% (70%–86%) for the detection of CRC stages II, III, and IV, respectively. Even substantially larger variation was seen in sensitivity by T-stage, with summary estimates ranging from 40% (21%–64%) for T1 to 83% (68%–91%) for T3-CRC. DISCUSSION: Although FITs detect 4 of 5 CRCs at stages II–IV, the substantially lower sensitivity for stage-I-CRC and, in particular, T1 CRC indicates both need and potential for further improvement in performance for the early detection of CRC.
1 December 2020 in Clinical Gastroenterology and Hepatology
Background: Meta-analyses of randomized controlled trials have shown that vitamin D supplementation reduces cancer mortality by 13%. Vitamin D fortification of foods may increase vitamin D levels in a similar manner as vitamin D supplementation and could achieve similar reductions in cancer mortality. Whereas some European countries already implemented widespread fortification of foods with vitamin D, in other countries only few or no foods are fortified. In this study, we estimated the reduction in cancer mortality presumably already achieved by current fortification policies in 2017 and the potential for further reductions if all countries had effective fortification. Methods: We reviewed scientific literature, publicly available information, and contacted health authorities to obtain information on current vitamin D food fortification policies in 34 European countries. Together with country-specific cancer death statistics from Eurostat, information on life expectancy, and country-specific fortification policies, we used data from studies on supplementation and serum 25(OH)D increases and cancer mortality to estimate numbers of probably already prevented cancer deaths and numbers of potentially further preventable deaths and years of life lost. Results: Current vitamin D fortification is estimated to prevent approximately 11,000 in the European Union and 27,000 cancer deaths in all European countries considered per year. If all countries considered here would implement adequate vitamin D fortification of foods, an estimated additional 129,000 cancer deaths (113,000 in the European Union) could be prevented, corresponding to almost 1.2 million prevented years of life lost (1.0 million in the EU) or approximately 9% of cancer deaths (10% in the EU). Interpretation: Systematic fortification of foods might considerably reduce the burden of cancer deaths in Europe.