"Differences in Expression and Prognostic Values of p16(Ink4) and VEGF in Squamous and Adenocarcinoma of the Lung"

Growing body of evidence suggests that molecular markers are an important prognostic marker for non-small lung cancer (NSCLC). Using targeted therapy based on these markers leads to improved outcomes in lung adenocarcinoma. However, progress of targeted therapy in squamous lung cancer is still modest. p16(ink) protein acts as tumor suppressor and vascular endothelial growth factor (VEGF) promotes tumor angiogenesis. Purpose of this study was to evaluate the difference in p16(ink4) and VEGF expression between squamous and adenocarcinoma of the lung; to evaluate the relationship of p16(ink4) and VEGF expression to survival outcomes in NSCLC patients, and the difference of their prognostic values between squamous and adenocarcinoma subtypes. 100 NSCLC patients (50 squamous and 50 adenocarcinoma) and 80 healthy individuals were included. p16(ink4) and VEGF proteins were immunohistochemicaly detected on formalin-fixed tissues. One- and 2-year progression-free survival (PFS) and overall survival (OS) were observed. p16(ink4) expression was significantly lower in squamous type compared to adenocarcinoma. In both squamous and adenocarcinoma, high VEGF expression correlated with worse 1-year PFS and OS, but only with worse 2-year PFS. Low p16(ink4) expression correlated with worse 1- and 2-year PFS, as well as OS, in both NSCLC subtypes. In squamous lung cancer p16(ink4) expression was an independent negative prognostic marker. Our study confirms the difference of p16(ink4) protein expression in squamous and adenocarcinoma of the lung. Besides anti-VEGF therapy, the regulation of p16(ink4) expression could have a therapeutic potential in NSCLC, especially in squamous lung cancer.