Prognostic Analyses of Resected Primary Lung Cancer by the Cox's Proportional Hazard Model, Using Tumor Doubling Time, Argyrophil Nucleolar Organizer Regions and Nuclear DNA content

A total of 65 resected cases of primary lung cancer were examined with regard to tumor doubling time (DT), argyrophil nucleolar organizer regions (Ag-NORs) and nuclear DNA content. Survival rates were compared among various categories according to each prognostic factor (univariate analyses), and significant factors affecting survival were determined by multivariate analyses using Cox's proportional hazard model. Univariate analyses showed significant differences in survival in relation to DT, smoking history, T factor, N factor, mean Ag-NOR counts, and DNA ploidy. Results of multivariate analyses proved that N factor, mean Ag-NOR counts, DNA ploidy and T factor were significant prognostic factors. There was a difference in biological significance between mean Ag-NOR counts and DNA ploidy. Mean Ag-NOR counts correlated to growth rate of tumor. DNA ploidy did not correlate with other prognostic factors, but was an independently significant prognostic factor.