Response of renal lesions during systemic treatment with sunitinib in patients with metastatic renal cell carcinoma: a single center experience with 14 patients.

PURPOSE: The tyrosine kinase inhibitor (TKI) sunitinib induces partial remissions (PR) in a substantial proportion of patients with metastatic renal cell carcinoma (mRCC). Only little is known about the activity of sunitinib in renal lesions in patients with metastatic disease, as most patients with synchronous metastases receive palliative nephrectomy.

METHODS: Fourteen patients with clear cell mRCC with renal lesions and sunitinib therapy (50 mg OD, 4/2 scheme) were retrieved retrospectively from clinic records. Tumor assessment consisted of CT scans at least every two cycles, analyzed according to RECIST. In 5 of 14 patients, renal tumors were considered as the primary tumor, while the remaining patients had kidney metastases. In total, 65 target lesions were evaluated.

RESULTS: The median progression-free survival (PFS) of sunitinib was 8.7 months (range: 2.7-40.2). Median overall survival (OS) from initiation of TKI therapy was 26 months (range: 3-55). Best response according to RECIST consisted of partial remission (PR) in 4 patients, stable disease (SD) in 7 patients, a complete remission (CR) in 1 patient, and 2 patients with progressive disease (PD). Analyzing the response of renal lesions only, 1 patient had PD, 8 patients had SD, 4 patients had PR, and 1 had a CR. Palliative nephrectomy was performed after two courses of sunitinib in 2 patients.

CONCLUSIONS: In our cohort, similar responses of renal tumors and peripheral metastases were achieved with sunitinib treatment. Our results support the use of sunitinib to control renal tumor lesions in metastatic patients.