Inhaled interleukin-2 in combination with low-dose systemic interleukin-2 and interferon alpha in patients with pulmonary metastatic renal-cell carcinoma: effectiveness and toxicity of mainly local treatment.

We describe here a mainly topical interleukin-2 (IL-2) application in pulmonary metastatic renal-cell carcinoma: a high-dose long-term inhalation of IL-2 (90% of IL-2 dose) and low-dose systemic subcutaneous IL-2 (10% of IL-2 dose) and systemic subcutaneous interferon alpha (IFN alpha). The effectiveness of this treatment is remarkable. No pulmonary metastases progressed during treatment. One complete response, 8 partial responses, and 6 cases of stable disease were achieved in the lungs of the 15 patients. In addition, 3 of 7 patients had partial responses and 1 of 7 had stabilization of non-pulmonary metastases. Overall response according to WHO criteria was 1 complete response, 6 partial responses, 2 mixed responses, 5 stable diseases and 1 progressive disease. Toxicity was low. Only WHO grade I toxicity occurred, except for a single grade II event (bronchospasm). This allowed long-term ambulatory treatment (1-23 months) inclusion of high-risk patients, and inclusion of patients with advanced disease. The expected mean survival of patients was 9.9 months, the actual mean survival is now 19.1 months, and 11 of 15 patients are still alive. Quality of life during treatment was good. Inhalation of IL-2 serves as a clinical model for high effectiveness and low toxicity of long-term local IL-2 application. We conclude that mainly local treatment might be the key to successful nontoxic use of IL-2 in cancer patients.