Overexpression of integrin αv correlates with poor prognosis in colorectal cancer

Aims Integrin alpha v subunits are involved in tumour angiogenesis and tumour progression in various types of cancers. Clinical trials evaluating agents targeting integrin alpha v are ongoing. Integrin alpha v expression has been reported in several cancers in association with tumour progression or poor survival. However, no study has addressed the prognostic influence of integrin alpha v expression on survival of patients with colorectal cancer (CRC). Methods Immunohistochemical staining of integrin alpha v was performed in 198 CRC samples to evaluate its prognostic significance. Results High expression of integrin alpha v was observed in 58.1% (115/189) of colorectal adenocarcinoma samples, while only in 11.5% (3/26) of tubular adenoma samples and in none of normal mucosa or hyperplastic polyp samples. It was more frequently found in female patients and less frequently observed in well differentiated tumours. The proportion of cases with high expression of integrin alpha v showed an increasing trend with increased T stage (p=0.032), N stage (p=0.006) and TNM stage (p=0.001). Patients displaying exuberant expression of integrin alpha v showed shorter overall survival (p=0.001) and disease-free survival (p=0.004). Elevated integrin alpha v expression was an independent prognostic factor for overall survival (HR: 2.04, 95% CI 1.16 to 3.56; p=0.013) and disease-free survival (HR: 2.19, 95% CI 1.16 to 4.13; p=0.015). Conclusions Overexpression of integrin alpha v is associated with advanced T and N stage and as an independent prognostic factor in CRC.