Prognostic value of nucleolar protein p120 in patients with resected lung adenocarcinoma.

Abstract

In this study we investigated the prognostic significance of proliferation-associated nucleolar protein p120 in primary resected lung adenocarcinoma because it reflects tumor growth fractions in vitro. Expression levels of p120 in tumors were assessed by immunohistochemistry in 74 patients who underwent radical resection. With clinical follow-up data, the prognostic significance of p120 calculated by labeling indices was evaluated using the Cox proportional hazards model. p120 protein was clearly detected in nucleoli of adenocarcinoma cells. Its expression levels widely varied in each sample from 8.5% to 67. 2%, with a mean +/- SD of 35.2% +/- 15.1%. No significant correlation was found between expression levels of p120 and clinicopathologic factors. However, the expression levels of p120 were negatively correlated with the tumor doubling time calculated with retrospective chest roentgenograms. Using a cutoff value of 35% in the labeling index of p120, patients with high expression of p120 experienced early recurrence and shorter survival compared with those who had low expression of p120. Multivariate analysis showed that p120 served as an independent, as well as the strongest, prognostic factor for resected lung adenocarcinoma. This report provides the first evidence that expression levels of p120 in tumor tissues can be used as an independent and powerful prognostic marker for resected lung adenocarcinoma.