Outcome of treatment discontinuation in patients with metastatic renal cell carcinoma and no evidence of disease following targeted therapy with or without metastasectomy

Background: It is unknown if discontinuation of targeted therapy (TT) and readministration in case of recurrence is feasible in patients with metastatic renal cell carcinoma (mRCC) in which complete response (CR) is achieved by TT alone or no evidence of disease (NED) with additional resection of residual metastases. Patients and methods: Patients in whom TT was discontinued after CR to TT alone or NED after additional metastasectomy were included in this retrospective analysis. Outcome criteria evaluated were time off TT, recurrence of metastases and response to re-exposure to TT. Univariate and multivariate analyses were carried out to identify variables potentially predictive of outcome. Results: In 36 patients with CR or NED under TT with sunitinib (22), sorafenib (11), bevacizumab/interferon (2) and temsirolimus (1), TT was discontinued. Recurrence was observed in 24 patients (66.7%). Re-exposure to TT was effective in 86.9% of these cases. Twelve patients (33.3%) remained recurrence free at a median follow-up of 12 months (range 3-31). Median time off TT was 7 months (range 1-31). Factors that correlate with outcome could not be identified. Conclusions: In the majority of patients with mRCC and CR or NED, discontinuation of TT was followed by recurrence, but re-exposure to TT was effective.