Cristina Hernando

A Gene Signature Combining the Tissue Expression of Three Angiogenic Factors is a Prognostic Marker in Early-stage Non-small Cell Lung Cancer

AbstractBackground Angiogenesis and lymphangiogenesis are key mechanisms for tumor growth and dissemination. They are mainly regulated by the vascular endothelial growth factor (VEGF) family of ligands and receptors. The aim of this study was to analyze relative expression levels of angiogenic markers in resectable non-small cell lung cancer patients in order to asses a prognostic signature that could improve characterization of patients with worse clinical outcomes. Methods RNA was obtained from tumor and normal lung specimens from 175 patients. Quantitative polymerase chain reaction was performed to analyze the relative expression of HIF1A, PlGF, VEGFA, VEGFA165b, VEGFB, VEGFC, VEGFD, VEGFR1, VEGFR2, VEGFR3, NRP1 and NRP2.ResultsUnivariate analysis showed that tumor size and ECOG-PS are prognostic factors for time to progression (TTP) and overall survival (OS). This analysis in the case of angiogenic factors also revealed that PlGF, VEGFA, VEGFB and VEGFD distinguish patients with different outcomes. Taking into account the complex interplay between the different ligands of the VEGF family and to more precisely predict the outcome of the patients, we considered a new analysis combining several VEGF ligands. In order to find independent prognostic variables, we performed a multivariate Cox analysis, which showed that the subgroup of patients with higher relative expression of VEGFA plus lower VEGFB and VEGFD presented the poorest outcome for both TTP and OS.ConclusionsThe relative expression of these three genes can be considered as an angiogenic gene signature whose applicability for the selection of candidates for targeted therapies needs to be further validated.

Prognostic implications of lymphangiogenic markers in early-stage NSCLC.

e21108 Background: The lymphatic system constitutes one of the most important pathways for tumor cell dissemination. The process of lymphangiogenesis is mainly regulated by VEGF family members. Specifically, the activation of VEGFR-3 by the binding of VEGF-C and VEGF-D is the initial signal stimulating the proliferation and migration of lymphatic endothelial cells. The aim of the present study was to analyze the expression of these genes in a cohort of resectable NSCLC patients and to correlate them with clinico-pathological variables and prognosis. METHODS RNA was obtained from tumor and normal lung specimens from 150 resectable NSCLC patients. RT-PCR was performed to assess the expression of VEGF-C, VEGF-D and VEGFR-3. Relative expression was normalized by an endogenous gene (GUS) using the Pfaffl formulae. Differences were considered statistically significant at p<0.05. RESULTS We found that tumor samples had a significant lower expression of VEGF-D compared to normal tissue (0.030X). In regard to the smoking status, the group of active smoking patients showed higher expressions levels of VEGF-C and VEGFR-3 genes (p=0.012 and p=0.014, respectively). There was s trend correlating lower expression of VEGF-D with lymph node metastasis. The survival analysis revealed that the group of patients with values of VEGF-D below the median had a significantly reduced OS rate (p=0.002). CONCLUSIONS VEGF-D is a master control gene of the lymphangiogenic process and may have a crucial role in the development of metastasis, therefore the lower expression of this gene found in tumor samples compared with normal lung tissue needs to be further investigated. Moreover, the expression of VEGF-D below the median is a poor prognostic marker for OS in our cohort of early-stage NSCLC patients. Supported by grants PS09-01149 and RD06/0020/1024 from ISCIII.