Proliferative activity following induction chemotherapy in squamous cell carcinoma of the head and neck. A histopathological and immunohistochemical study using monoclonal antibodies.

Forty-six patients with advanced head and neck squamous cell carcinomas received two courses of chemotherapy with cisplatinum and bleomycin before undergoing cancer surgery. After surgery, histological serial sections of the resection specimens were examined. Biopsies from each resected specimen were shock-frozen for immunohistochemical examinations using the monoclonal antibodies Ki-67 and RPN-511, which are associated with cell proliferation. In no case did the morphologic analysis demonstrate complete tumor regression after chemotherapy. Thirty-seven patients showed partial tumor regressions histologically, as seen by tumor shrinkage of more than 50%. Nine of the specimens showed only minor regressions, with shrinkage less than 50%. The immunostaining of the frozen sections revealed in all cases the expressions of the Ki-67 nuclear antigen and the presence of specific transferrin (RPN-511) receptors in the proliferative compartments of the carcinomas.