The association of immunodeficiency with
head and neck squamous cell carcinoma has generated the concept of supplying immunologically active agents as a means of treating these
cancers. One of the most active immunologic messengers is
interferon gamma, which has been observed in our laboratories to also have a direct cytotoxic effect on cultures of
squamous cell carcinoma derived from the head and neck. To test the feasibility of treating patients with advanced but resectable
head and neck cancer with this agent, we designed a phase I-II trial of recombinant human
interferon gamma using a 24-hour infusion repeated weekly for four times. In this study, both
tumor and immunologic parameters were studied before and
after treatment. Eight patients were entered into the study with the highest recombinant human
interferon gamma dose attempted being 0.25 mg/m2 per 24 hours. Minimal side effects were observed. Three patients had clinically measurable responses, four had stabilization of disease, and one had progression while receiving treatment. Histopathologic results of treatment were similar to in vitro observations.
Necrosis, as well as differentiation of
tumor cells, was observed. In some
tumors there was a marked decrease in cellularity without a change in
tumor volume due to increased extracellular
keratin deposition. Our study indicates that evaluation of adoptive immunotherapy trials in
head and neck cancer needs to include parameters other than simple
tumor regression as an end point, otherwise therapeutically important lymphokine-induced changes may be missed. Further evaluation of recombinant human
interferon gamma and agents that induce human
interferon gamma are warranted.