Study Demonstrates New Prognostic Biomarkers in Pancreatic Cancer
In this study, the investigators aimed to evaluate the expression levels of EGFR and IGF-1R proteins and measure IGF-1R gene copy number in pancreatic ductal adenocarcinoma, and correlate these data with the patients' characteristics and prognosis. Using immunohistochemical staining to evaluate expression in formalin-fixed paraffin-embedded tissue derived from tumor specimens recovered during surgery as well as chromogenic in situ hybridization to quantify IGF-1R gene copy number, the investigators were able to meet the primary outcome. Secondary outcomes included associations between EFGR and IGF-1R expression and pathologic variables.
The investigators reported data on 105 patients. EGFR expression was present in 30.4% of cases and was associated with lymph node metastasis (P=.038). IGF-1R was overexpressed in 53% of tumors and correlated with higher tumor grade (P=.033). High membranous expression of EGFR (P <.001) and/or IGF-1R (P=.004), the cytoplasmic detection of EGFR (P=.027), and high expression levels of IGF-1R in the tumoral stroma (P<.001) were all associated with shorter overall survival, being significantly better in patients who simultaneously do not express membranous EGFR or stromal IGF-1R.
The investigators concluded: “EGFR and IGF-1R expression, in neoplastic and stromal cells, seems to be an important prognostic factor.”