Relationship between expression of IGFBP7 and clinicopathological variables in gastric cancer

Aims Insulin-like growth factor binding protein 7 (IGFBP7) is reported to have tumour suppressor function through an IGF-dependent pathway in various malignant tumours. However, the expression of IGFBP7 in adenocarcinoma and its relationship with tumour progression and survival differs among studies. Our aims were to investigate the relationship between the expression of IGFBP7 and clinicopathological variables and outcomes of patients with gastric cancer. Methods Tumour samples were obtained from 219 patients with gastric cancer who underwent gastrectomy. The expression of IGFBP7 protein was examined by immunohistochemical staining. IGFBP7 mRNA levels were analysed using real-time quantitative reverse-transcriptase PCR in 24 of the gastric cancer tumours and in adjacent non-tumour tissues. Correlation of IGFBP7 expression with clinicopathological features was analysed. Results The protein expression of IGFBP7 was positively correlated with depth of invasion, lymph node metastasis, distant metastasis or recurrence and pathological stage. High expression of IGFBP7 protein was associated with a significantly worse disease-specific survival (p<0.001) and was an independent prognostic factor in multivariable analysis (HR, 4.8; 95% CI 2.1 to 10.6; p<0.001). The IGFBP7 mRNA level was significantly higher in advanced gastric cancer than in early gastric cancer, in tumours with lymph node metastasis than in tumours without lymph node metastasis, and in tumours with distant metastasis or recurrence than in tumours without distant metastasis or recurrence. Conclusions Overexpression of IGFBP7 was associated with tumour progression and poor survival in gastric cancer. IGFBP7 may play a role in tumour progression in gastric cancer.