Objective: To induce tumor regression with immunotherapy and to characterize the histology.
Setting: National Institute of Cancerology, Mexico City, Mexico.
Patients: Thirteen patients with advanced squamous cell carcinoma of the head and neck region.
Intervention: A 21-day cycle of preoperative immunotherapy, including a single intravenous infusion of low-dose cyclophosphamide (300 mg/M2), 10 daily perilymphatic injections of a natural cytokine mixture (approximately 150 units interleukin-2 equivalence by enzyme-linked immunosorbent assay), daily oral indomethacin, and daily oral zinc with multivitamins.
Outcome measures: Pretreatment biopsies were performed to confirm the diagnosis and to characterize the lesion by standard pathologic criteria, including the degree of tumor-associated lymphocytes. Clinical responses were assessed at surgery, and the specimen was analyzed with respect to changes in tumor morphology and lymphoid and inflammatory infiltration (T and B lymphocytes, plasma cells, macrophages, granulocytes, and giant cells). The presurgical and postsurgical characteristics were ascribed percentages based on a representative section.
Results: Prior to treatment, on average the biopsies demonstrated 77% solid tumor with 14% stroma and 9% sparse infiltration of lymphocytes. After treatment, one patient had a complete clinical response and showed only residual inflammatory cells and fibrosis. One patient had no clinical or histologic response. Of the remaining 11 patients, 4 had partial, 6 had minor, and 1 had no response. Tumors were reduced an average of 41% (16% solid and 25% fragmented) and lymphoid infiltration increased to 45% without change in residual stroma.
Conclusions: The pathologic changes viewed in the context of the clinical findings indicate that this immunotherapy protocol induces immune regression of the tumor, mediated predominantly by T and B lymphocytes, and thus elicits a tumor-specific immune reaction.