Prognostic significance of argyrophilic nucleolar organizer region (AgNOR) in resected non-small cell lung cancer (NSCLC)

The expression of the nucleolar organizer regions (NORs) was quantified inparaffin sections of tumors and lymph node metastasis, by means of digitalimage analysis, in 75 patients with resected non-small cell lung cancer(NSCLC). Patients were divided in two groups: early stage (stages I and II)and advanced stage (stages IIIa, IIIb and IV). The prognostic significanceof AgNOR expression was tested by Cox regression analysis in modelscontrolled for age, sex, vital status, stage and histological type. Tumorsat early stages had a lower expression of AgNOR than those at more advanceddiseases. The mean values obtained for NORs in advanced disease were almostthe same as those in the primary tumors when compared with thecorresponding lymph node metastasis (r = 0.90; p < 0.01; linearregression). The prognostic role of AgNOR was significant only for tumorsat stages I and II and not for advanced neoplasms (stages IIIa, IIIb andIV). These results encourage the inclusion of AgNOR quantitation in routinematerial, especially in early lung cancer.