The prognostic significance of N‐myc downregulated gene 1 in lung adenocarcinoma

Abstract

It has been reported that N-myc downstream regulated gene 1 (NDRG1) is related to the prognosis of non-small cell lung cancer (NSCLC), and associated with c-Myc degradation in NSCLC cell lines. However, the relationship of NDRG1 to prognosis or c-Myc expression in lung adenocarcinoma has not been well clarified. The present study was designed to investigate the prognostic significance of NDRG1 and/or c-Myc expression in lung adenocarcinoma using immunohistochemistry with a tissue microarray. We examined 184 lung adenocarcinomas and observed low expression of NDRG1 in adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), whereas high expression of NDRG1 was seen in invasive adenocarcinoma. Each of the clinicopathological features except age was significantly correlated with NDRG1 expression. Kaplan-Meier curves indicated that high expression of NDRG1 was significantly correlated with poor prognosis in comparison with low expression (log-rank, P < 0.001). Univariate and multivariate analyses indicated that vascular invasion (P = 0.012), lymphatic permeation (P = 0.038), and NDRG1 expression (P = 0.026) were independent prognostic factors. Expression of NDRG1 and positivity for c-Myc were significantly correlated (P = 0.005). These findings indicate that NDRG1 expression is associated with both prognosis and c-Myc expression in lung adenocarcinoma.