Treatment of Oral Cavity and Oropharynx Squamous Cell Carcinoma with Perilymphatic Interleukin-2

Abstract

We describe the correlations between the clinical and histologic findings in an initial series of 60 patients with T2–4, N0–3, MO squamous cell carcinoma (SCC) of the oral cavity or oropharynx enrolled in a randomized trial set up to evaluate whether the disease-free interval and survival are extended when perilymphatic injections of recombinant interleukin-2 (rIL-2) are combined with routine surgery and radiotherapy. Twenty-nine patients were operated on only (controls). The other 31 received two daily injections of 2,500 U rIL-2, one near the mastoid process on the same side as the tumor and the other under the chin, for 10 days before surgery, and further injections on the nonoperated-on side on a monthly basis for 1 year starting 4 weeks after surgery (or radiotherapy, where necessary) in an effort to upregulate the immune system and delay recurrence. Their surgical specimens displayed a significantly greater inflammatory reaction, larger areas of necrosis, and more intense sclerosis. The inflammatory tumor infiltration consisted of eosinophils, plasma cells, and CD25+ and human leukocyte antigen (HLA)-DR+ lymphocytes. However, no correlations were apparent with regard to the intensity of necrosis, eosinophil infiltration, and the number of DR+ cells and the clinical outcome. By contrast, the correlation between CD25+ cells and a significantly longer disease-free survival suggests that induction of T-cell reactivity, and perhaps specific immunity, is the only important aspect of rIL-2–induced antitumor reactivity.