Metastasectomy following incomplete response to high-dose interleukin-2

To evaluate our experience with metastasectomy following partial response or stable disease after treatment with high-dose interleukin-2 (HD IL-2).

A total of 305 patients with metastatic renal cell carcinoma or melanoma treated with HD IL-2 over a 12-year period were reviewed. Age, objective response, and overall survival data were evaluated using standard RECIST criteria and Kaplan-Meier estimates.

The average age was 55.3 years (range, 15-85) and 245 (80.3%) patients had melanoma and 60 (19.7%) had renal cell carcinoma. The objective response rate to IL-2 for all patients was 13.6% and median survival was 16.8 months. Complete follow-up data were available for 236 patients with 147 (62.3%) progressing after treatment and 8 (3.3%) with a complete response. Incomplete responses were seen in 81 (34.3%) patients, including 57 (24.2%) patients with stable disease and 24 (10.1%) with partial responses. Of these 81 incomplete responders, 15 (18.5%) underwent subsequent metastasectomy. Patients without surgery had overall survival of 38.2 months and median survival has not yet been reached in those who underwent metastasectomy (P = 0.026).

The data support prospective evaluation of metastasectomy following incomplete therapeutic responses to immunotherapy and defines a new role for surgical resection following IL-2 and perhaps other immunotherapy regimens.