Immunotherapy with interleukin-2 and α-interferon in patients with metastatic renal cell cancer with in situ primary cancers: A pilot study

A total of 12 patients with stage 4 renal cell carcinoma and primary renal tumors in situ was entered into a pilot study using treatment with interleukin-2 and α-interferon followed by radical nephrectomy. Of the patients 11 underwent nephrectomy after an initial course of immunotherapy. Ten patients were able to receive a second course of immunotherapy given after nephrectomy. One patient achieved a complete response of lung and mediastinal metastases without any change in the primary renal tumor but after nephrectomy the patient remained in complete remission for greater than 11 months. A total of 3 patients achieved a partial response at some extrarenal sites but they had progression elsewhere. Toxicity was similar to previous experience with this immunotherapy regimen. Therefore, we demonstrated that metastatic tumor regression is possible with primary renal tumors in situ and that aggressive interleukin-2-based immunotherapy can be tolerated in the presence of a large renal tumor.