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

Purpose: In this study we investigated the prognostic significance of proli feration-associated nucleolar protein p120 in primary resected lung adenoca rcinoma because it reflects tumor growth fractions in vitro. Patients and methods: Expression levels of p120 in tumors were assessed by immunohistochemistry in 74 patients who underwent radical resection. With c linical follow-up data, the prognostic significance of p120 calculated by l abeling indices was evaluated using the Cox proportional hazards model. Results: p120 protein was clearly detected in nucleoli of adenocarcinoma ce lls, 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 foun d between expression levels of p120 and clinicopathologic factors. However, the expression levels of p 120 were negatively correlated with the tumor d oubling time calculated with retrospective chest roentgenograms. Using a cu toff valve of 35% in the labeling index of p120, patients with high express ion of p120 experienced early recurrence and shorter survival compared with those who had low expression of p120. Multivariate analysis showed that p1 20 served as an independent, as well as the strongest, prognostic factor fo r resected lung adenocarcinoma. Conclusion: This report provides the first evidence that expression levels of p120 in tumor tissues can be used as an independent and powerful prognos tic marker for resected lung adenocarcinoma. (C) 1999 by American Society o f Clinical Oncology.