ARGYROPHILIC NUCLEOLAR ORGANIZER REGION COUNTS IN SQUAMOUS-CELL CARCINOMAS OF THE HEAD AND NECK AFTER IRRADIATION AND CHEMOTHERAPY

After irradiation or chemotherapy of tumors of the head and neck, hist ological alterations might be difficult to assess. In 30 cases of squa mous cell carcinomas of the pharynx, changes in argyrophilic nucleolar organizer region (AgNOR) counts were investigated after therapy. Afte r treatment a significant decrease of AgNOR counts was detected (P < 0 .001). No significant differences could be found between groups treate d with radiotherapy, chemotherapy or a combination of radiotherapy and chemotherapy. These findings suggest that AgNOR counts might be usefu l to assess cytotoxic effects on a subcellular level.