Association between long-term energy balance-related factors and survival in colorectal cancer overall and by metabolic Warburg-subtypes.

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.

Expression of proteins associated with the Warburg-effect and survival in colorectal cancer.

Previous research has suggested that the expression of proteins related to the Warburg effect may have prognostic value in colorectal cancer (CRC), but results remain inconsistent. Our objective was to investigate the relationship between Warburg-subtypes and patient survival in a large population-based series of CRC patients. In the present study, we investigated the expression of six proteins related to the Warburg effect (LDHA, GLUT1, MCT4, PKM2, p53, PTEN) by immunohistochemistry on tissue microarrays (TMAs) from 2,399 incident CRC patients from the prospective Netherlands Cohort Study. Expression levels of the six proteins were combined into a pathway-based sum-score and patients were categorised into three Warburg-subtypes (low/moderate/high). The associations between Warburg-subtypes and CRC-specific and overall survival were investigated using Kaplan-Meier curves and Cox regression models. CRC patients were classified as Warburg-low (n = 695, 29.0%), Warburg-moderate (n = 858, 35.8%) or Warburg-high (n = 841, 35.1%). Patients with Warburg-high CRC had the poorest CRC-specific [hazard ratio (HR) 1.17; 95% CI 1.00-1.38] and overall survival (HR 1.19; 95% CI 1.05-1.35), independent of known prognostic factors. In stratified analyses, this was particularly true for patients with tumour-node-metastasis (TNM) stage III CRC (HRCRC-specific 1.45; 95% CI 1.10-1.92 and HRoverall 1.47; 95% CI 1.15-1.87), and cancers located in the rectum (HRoverall 1.56; 95% CI 1.15-2.13). To our knowledge, this is the first study to identify the prognostic value of immunohistochemistry-based Warburg-subtypes in CRC. Our data suggest that Warburg-subtypes are related to potentially important differences in CRC survival. Further research is required to validate our findings and to investigate the potential clinical utility of these Warburg-subtypes in CRC.