Proliferating cell nuclear antigen expression and argyrophilic nucleolar organizer regions as factors influencing prognosis of surgically treated lung cancer patients.

Cell proliferation in 211 primary non-small cell lung carcinomas was assessed by using an immunostaining of proliferating cell nuclear antigen (PCNA) and a silver staining of argyrophilic nucleolar organizer region (Ag-NOR). More than 5% PCNA positive cells was designated PCNA(+), and less than 5% was PCNA(-). A mean number or more of the Ag-NOR was a high Ag-NOR count, and less than the mean number was a low Ag-NOR count. The proportion of the tumors with PCNA(+) and high Ag-NOR counts showed an increase in patients in an advanced stage of the disease (P < 0.05). In 125 patients with stage I disease, the 5-year survival rate was 20% in patients with PCNA(+) and high Ag-NOR counts, compared with 47% in those with either PCNA(+) or high Ag-NOR counts and 76% in those with PCNA(-) and low Ag-NOR counts (P < 0.05). Our data suggest that the tumors with PCNA(+) and high Ag-NOR counts have a high proliferative activity. The combination analysis of PCNA and Ag-NOR may be useful in assessing prognosis in lung cancer, even in stage I disease.