Nucleolar Organizer Regions as a Prognostic Indicator for Stage I Non-Small Cell Lung Cancer

Abstract

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 < 0.01). The mean Ag-NOR counts were lower in patients with N₀ disease than in those with N₁ and N₂ disease (P < 0.01); lower in patients with stage I disease than in those with stage II, IIIA, IIIB, or IV disease (P < 0.01); and lower in patients with adenocarcinoma than in those with squamous cell carcinoma (P < 0.01) or large-cell carcinoma (P < 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 <3.80 and ≥3.80 were 78 and 44%, respectively, including 78% and 25% for adenocarcinoma, respectively (P < 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.