Nucleolar organizer regions as a prognostic indicator for stage I non-small cell lung cancer.

When the number of silver-stained nucleolar organizer regions (Ag-NORs) was counted in 274 patients with non-small cell lung cancer, the mean number per nucleus in patients overall was 5.07 +/- 1.92 (SD). With the use of the tumor (T)-nodes (N)-metastasis (M) classification, the mean Ag-NOR count for patients with T1 and T2 disease was statistically lower than that for those with T3 and T4 disease (P less than 0.01). The mean Ag-NOR counts were lower in patients with N0 disease than in those with N1 and N2 disease (P less than 0.01); lower in patients with stage I disease than in those with stage II, IIIA, IIIB, or IV disease (P less than 0.01); and lower in patients with adenocarcinoma than in those with squamous cell carcinoma (P less than 0.01) or large-cell carcinoma (P less than 0.05). In 131 patients with stage I disease, the mean Ag-NOR count was 3.80 +/- 1.32, and the 5-year survival rates of patients with Ag-NOR counts of less than 3.80 and greater than or equal to 3.80 were 78 and 44%, respectively, including 78% and 25% for adenocarcinoma, respectively (P less than 0.01). However, there was no statistically significant difference for those in stage II, IIIA, IIIB, or IV, and in stage I (without an adenocarcinoma). Because patients with stage I non-small cell lung cancer and a high number of Ag-NORs had a poor prognosis, Ag-NORs can serve as a pertinent marker of an early recurrence.