Abstract
BACKGROUND: This study investigated the relationship of obesity, insulin resistance, inflammation and angiogenesis with cancer progression and survival in a colorectal cancer cohort.
METHODS: Clinical and pathological data, along with anthropometric and follow-up data, were collected from 344 consecutive colorectal cancer patients. Serum samples at diagnosis were analysed by immunoassay for adiponectin, C-reactive protein (CRP), vascular endothelial growth factor-A (VEGF-A), angiopoietin-2 (Ang-2), insulin-like growth factor-1 (IGF-1), insulin and C-peptide.
RESULTS: Serum Ang-2 and VEGF-A levels increased with tumour T stage (P = 0.007 and P = 0.025, respectively) and N stage (P = 0.02 and P = 0.03, respectively), and correlated with CRP levels (r = 0.43, P<0.001 and r = 0.23, P<0.001, respectively). Angiopoietin-2 correlated with C-peptide (r = 0.14, P = 0.007) and VEGF-A with IGF-1 in males (r = 0.25, P = 0.001). Kaplan-Meier analysis showed that patients with high serum levels of CRP and Ang-2 had significantly reduced survival (both P <= 0.001). After adjusting for tumour stage and age, Ang-2 remained a significant predictor of survival. The CRP levels were inversely associated with survival in American Joint Committee on Cancer stage II patients (P = 0.038), suggesting that CRP could be used to support treatment decisions in this subgroup. Serum markers and anthropometric measures of obesity correlated with each other, but not with survival.
CONCLUSION: Our study supports the concept that obesity-related inflammation, rather than obesity itself, is associated with colorectal cancer progression and survival. The study confirms serum Ang-2 as a predictive marker for outcome of colorectal cancer. British Journal of Cancer (2011) 104, 51-59. doi:10.1038/sj.bjc.6606005 www.bjcancer.com Published online 16 November 2010 (C) 2011 Cancer Research UK