['Esophageal adenocarcinoma (EAC) incidence increases, maybe due to increasing prevalences of obesity and diabetes. Concurrent hyperinsulinemia might promote carcinogenesis via the insulin-like growth factor-I receptor (IGF-1R). Expression of the IGF-1R was studied in correlation with diabetes and prognostic parameters.', 'Patients with EAC undergoing esophagectomy were prospectively selected. From resected tumors a tissue microarray was constructed. Immunohistochemistry evaluated IGF-1R-expression. Logistic-, cox regression models and survival analyses assessed if diabetes and IGF-1R-expression were associated with prognostic parameters. IGF-1R-expression in normal and Barrett tissues was studied.', 'Absence or low IGF-1R-expression was associated with T3-, grade 3 tumors and R1 resections (P\u2009=\u20090.001, P\u2009=\u20090.025, P\u2009<\u20090.001, respectively). Logistic regression showed that this was associated with R1 resections (HR 0.24, 95%CI 0.11-0.52). Diabetes was not associated with IGF-1R-expression (P\u2009=\u20090.612). Absence or low IGF-1R-expression decreased 5-year overall survival (P\u2009=\u20090.023) univariably, but not multivariably. IGF-1R-expression was present in Barrett tissues, but diminished in high-grade dysplasia.'] Is absence or low IGF-1R-expression in esophageal adenocarcinoma associated with tumor invasiveness and radicality of surgical resection?