Main effects and interactions of carbonic anhydrase IX, hypoxia-inducible factor-1α, ezrin and glucose transporter-1 in multivariate analysis for disease outcome in rectal cancer.

Strong expression of carbonic anhydrase IX (CA IX), hypoxia-inducible factor-1α (HIF-1α), ezrin and glucose transporter-1 (GLUT-1) were previously shown to be interrelated and to affect clinicopathological prognostic factors. In the current study, operative samples from 178 rectal cancer patients, 77 treated with short-course, 47 with long-course preoperative radiotherapy (RT), and 54 with no preoperative treatment, as well as 80 preoperative biopsies from the RT group were analysed using multivariate modelling in order to assess the role of these markers as predictors of disease outcome. Multivariate survival analysis revealed several sets of panels with the potential ability to identify patients at increased or decreased risk of dying from their disease or disease recurrence. The most remarkable panel, consisting of moderate/strong expression of CA IX, positive HIF-1α expression and negative/weak GLUT-1 expression in operative samples and negative/weak ezrin expression in preoperative biopsies was associated with 47.5-fold risk of death from this disease. These results should, however, be interpreted with caution due to the heterogeneity of the patient population in this retrospective study.