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Background: Energy balance-related factors [body mass index (BMI), waist circumference, physical activity] have been associated with colorectal cancer risk. Warburg effect activation via PI3K/Akt signaling is one of the proposed mechanisms. We investigated whether energy balance-related factors were associated with risk of Warburg subtypes in colorectal cancer. Methods: We investigated this using immunohistochemistry for six proteins involved in the Warburg effect (LDHA, GLUT1, MCT4, PKM2, P53, PTEN) on tissue microarrays of 2,399 incident colorectal cancer cases from the prospective Netherlands Cohort Study (ntotal = 120,852; nsubcohort = 5,000; aged 55-69 in 1986; 20.3 years follow-up). Data analyses included 3,911 subcohort members and 1,972 colorectal cancer cases with complete covariate data. Expression levels of all proteins were combined into a pathway-based sum score and categorized into three "Warburg subtypes" (Warburg-low/moderate/high). Multivariable Cox regression analyses were used to estimate associations of BMI, clothing size (waist circumference proxy), and physical activity with Warburg subtypes in colorectal cancer. Results: BMI and clothing size were positively associated with Warburg-moderate and Warburg-high colon cancer risk in men (Pheterogeneity = 0.192). In women, clothing size was positively associated with Warburg-low and Warburg-high colon cancer (Pheterogeneity = 0.005). Nonoccupational physical activity was inversely associated with Warburg-low and Warburg-moderate colon cancer in women (Pheterogeneity = 0.045), but positively associated with Warburg-high rectal cancer in men (Pheterogeneity = 0.089). Conclusions: The Warburg effect might be involved in associations between adiposity and colon cancer risk, though additional mechanisms could be at play in women as well. The inverse association between physical activity and colon cancer might be explained by mechanisms other than the Warburg effect. [ABSTRACT FROM AUTHOR]

Background: Scoring of immunohistochemistry (IHC) staining is often done by non-pathologists, especially in large-scale tissue microarray (TMA)-based studies. Studies on the validity and reproducibility of scoring results from non-pathologists are limited. Therefore, our main aim was to assess interobserver agreement between trained non-pathologists and an experienced histopathologist for three IHC markers with different subcellular localization (nucleus/membrane/cytoplasm). Methods: Three non-pathologists were trained in recognizing adenocarcinoma and IHC scoring by a senior histopathologist. Kappa statistics were used to analyze interobserver and intraobserver agreement for 6,249 TMA cores from a colorectal cancer series. Results: Interobserver agreement between non-pathologists (independently scored) and the histopathologist was "substantial" for nuclear and membranous IHC markers (Krange= 0.67-0.75 and Krange= 0.61-0.69, respectively), and "moderate" for the cytoplasmic IHC marker (Krange= 0.43-0.57). Scores of the three non-pathologists were also combined into a "combination score" (if at least two non-pathologists independently assigned the same score to a core, this was the combination score). This increased agreement with the pathologist (Knuclear = 0.74; Kmembranous = 0.73; Kcytopasmic = 0.57). Interobserver agreement between non-pathologists was "substantial" (Knuclear = 0.78; Kmembranous = 0.72; Kcytopasmic = 0.61). Intraobserver agreement of non-pathologists was "substantial" to "almost perfect" (Knuclear,range = 0.83-0.87; Kmembranous,range = 0.75-0.82; Kcytopasmic = 0.69). Overall, agreement was lowest for the cytoplasmic IHC marker. Conclusions: This study shows that adequately trained non-pathologists are able to generate reproducible IHC scoring results, that are similar to those of an experienced histopathologist. A combination score of at least two non-pathologists yielded optimal results. [ABSTRACT FROM AUTHOR]

Background: Long-term energy balance-related factors (i.e. lifestyle and physiological factors that influence the equilibrium between energy intake and energy expenditure over an extended period) like body mass index (BMI) are linked to colorectal cancer (CRC) risk, but their impact on CRC survival is unclear. We explored associations between these long-term energy balance-related factors and survival, and examined potential differences across metabolic Warburg-subtypes., Methods: Associations between long-term energy balance-related factors and survival in the total series of CRC patients (n=2,347) obtained from the prospective Netherlands Cohort Study, as well as according to Warburg-subtype (Warburg-low: n=652, Warburg-moderate: n=802, Warburg-high: n=797), were investigated using Cox regression analysis., Results: Among the long-term energy balance-related factors studied, only increasing pre-diagnostic BMI was associated with a borderline significant poorer overall survival in CRC patients (HR5kg/m2 1.07; 95%CI 0.99-1.15). Stratified analyses showed that pre-diagnostic weight gain (HR5kg 1.06; 95%CI 1.00-1.12), and potentially increased height (HR5cm 1.04; 95%CI 0.98-1.11), were associated with poor overall survival only in patients with Warburg-high CRC. Increasing pre-diagnostic BMI was associated with poor survival only in patients with Warburg-moderate CRC (CRC-specific: HR5kg/m2 1.12; 95%CI 0.96-1.32, overall: HR5kg/m2 1.20; 95%CI 1.05-1.36). No consistent patterns were observed across energy-restriction proxies., Conclusions: Maintaining a healthy pre-diagnostic BMI may be beneficial for CRC survival. Moreover, associations between pre-diagnostic BMI, weight change, early-life energy restriction, height and CRC survival differed according to Warburg-subtype., Impact: Understanding the biological pathways involved in associations between energy balance-related factors and CRC survival could help refine prevention strategies in the future.