High-dose interleukin-2 therapy for metastatic renal cell carcinoma: a contemporary experience.

Objective: To present our experience of high-dose interleukin-2 (HDIL-2) in a high-volume National Cancer Institute-designated center for patients with metastatic renal cell carcinoma (mRCC).

Methods: Patients with mRCC who received HDIL-2 monotherapy as a first- or second-line therapy during 2004-2011 were identified. Demographics, pathologic variables, renal function, time until the start of HDIL-2 therapy, number of cycles (1-3), responses (complete response, partial response, stable disease, and progressive disease), and primary renal cell carcinoma treatment were analyzed. Progression-free survival and overall survival (OS) were determined.

Results: Of 906 patients in the kidney cancer database, 91 patients with mRCC were treated with HDIL-2 and 18 patients (20.5%) underwent prior cytoreductive nephrectomy. Median age was 51 years, and 73.9% were men. Median follow-up was 45 months. Pretreatment renal function impairment led to more treatment cycles (2-3) than in those with adequate initial kidney function (92.3% vs 50.6%, respectively; P = .002). Lower tumor stage correlated with a better response (P = .023) and with longer time from diagnosis to initiation of HDIL-2 (P = .011). Complications included hypotension (67.4%), renal impairment (63%), impaired liver function (42.4%), and thrombocytopenia (31.5%). Four patients (4.5%) had a complete response, 10 (11.4%) had a partial response, and 28 (31.8%) had a stable disease. Median progression-free survival and OS were 8.6 and 35.5 months, respectively. The estimated 2-year OS rate was 60.6%.

Conclusion: Incorporating HDIL-2 therapy in the treatment strategies for mRCC added to the patients' survival in this series. HDIL-2 therapy is well tolerated in patients with pre-existing renal impairment with no long-term renal toxicity.