Nucleolar organizer regions in glottic carcinomas: comparison of DNA cytofluorometry and clinicopathological analysis

The significance of nucleolar organizer regions (NORs) and nuclear DNA content in 73 glottic carcinomas was assessed for proliferative activity and tumor progression. NORs stained with silver colloid were counted, and nuclear DNA content was assayed by cytofluorometry. The cytofluorometric study demonstrated that the percentage of tumors with aneuploidy tended to increase as histological differentiation decreased. Survival rates of patients with diploid and aneuploid tumors were not significantly different. AgNOR staining revealed that mean AgNOR numbers rose as histological differentiation of tumors decreased. Moreover, as T and N categories and stages showed advancing malignancy, mean AgNOR numbers tended to rise. However, there was no significant difference in survival rates between tumors with low and with high AgNOR counts. These studies indicate that while AgNOR staining is better than DNA cytofluorometry for determining histological differentiation of glottic carcinoma, neither is of prognostic value at the present time.