Clinicopathological significance and impact on outcomes of the gene expression levels of IGF-1, IGF-2 and IGF-1R, IGFBP-3 in patients with colorectal cancer: Overexpression of the IGFBP-3 gene is an effective predictor of outcomes in patients with colorectal cancer

Abstract

The insulin‑like growth factors (IGF) system is involved in tumor proliferation, invasion and metastasis in cancer. The current study investigated the association of IGF‑1, IGF‑2 and IGF‑1 receptor (IGF‑1R), IGF binding proteins type 3 (IGFBP‑3) mRNA expression levels with clinicopathological characteristics and outcomes of 202 patients with untreated colorectal cancer (CRC). IGF‑1, IGF‑2, IGF‑1R and IGFBP‑3 mRNA expression levels were analyzed in surgical specimens of cancer tissues and adjacent normal mucosa cells using reverse transcription‑quantitative polymerase chain reaction. The IGF‑1R gene expression level was significantly higher in cancer tissue compared with adjacent normal mucosa. By contrast, IGF‑1 gene expression levels were reduced in cancer tissue compared with normal mucosa. IGF‑2 and IGFBP‑3 gene expression levels did not differ significantly between cancer tissue and adjacent normal mucosa. As for the association of gene expression and clinicopathological characteristics, IGFBP‑3 gene expression was significantly associated with lymph node metastasis. High IGFBP‑3 gene expression was associated with poor 5‑year overall survival compared with patients with low IGFBP‑3 expression. Furthermore, IGFBP‑3 gene expression was identified as an independent prognostic factor using multivariate analysis. Overexpression of the IGFBP‑3 gene is considered an effective independent predictor of outcomes in patients with CRC.