Vegfr-2 in late stage/high grade squamous cell carcinoma of the lung: A cohort study

Background: VEGFR-2 is a critical molecule for tumor angiogenesis and a target for assessment of anti-angiogenic therapy. Although, its expression and functionality has been correlated in various cancers, not many studies are available in the context of lung cancer. Patients and Methods: In this study, the expression of VEGFR-2 was analyzed in clinically relevant tissue samples of Non-Small Cell Lung Cancer (NSCLC) patients (n=108, surgically resected archival tumor samples) with histopathologically confirmed Squamous Cell Carcinoma (SCC) sub-type and compared with appropriate controls. Expression of endogenous level of VEGFR-2 was assessed by Western blotting and densitometry. Results: Clinicopathological data suggested that the incidence of SCC in local population with respect to age, sex, tumor stage and histology was typical and consistent with reported global incidence of NSCLC. We observed differential expression of VEGFR-2 based on the staging of tumors. Poorly differentiated SCC samples show higher expression of VEGFR-2, expression levels of VEGFR-2 in moderately differentiated SCC were comparable while expression was lower in well differentiated SCC samples when compared to their available respective controls. Further corroborating this observation, external control samples (non-tumor patient samples) expressed VEGFR-2 levels comparable to patient tissue controls in turn pointing to a possible stage-based prognostic significance for SCC. Conclusion: Our results highlight a strong correlation of VEGFR-2 expression, with late stage SCC compared to early stage SCC. Thus, VEGFR-2 may be actively involved in late progression of SCC, which constitutes a major chunk of NSCLC and may also have prognostic and therapeutic relevance.