Complete remission with tyrosine kinase inhibitors in renal cell carcinoma

Purpose: Complete remission (CR) is uncommon during treatment for metastatic renal cell carcinoma (mRCC) with tyrosine kinase inhibitors (TKIs), but it may occur in some patients. It remains a matter of debate whether therapy should be continued after CR. Methods: A multicenter, retrospective analysis of a series of patients with mRCC who obtained CR during treatment with TKIs (sunitinib or sorafenib), either alone or with local treatment (surgery, radiotherapy, or radiofrequency ablation), was performed. Results: CR was identified in 64 patients; 36 patients had received TKI treatment alone and 28 had also received local treatment. Most patients had clear cell histology (60 of 64 patients), and all had undergone previous nephrectomy. The majority of patients were favorable or intermediate risk; however, three patients were poor risk. Most patients developed CR during sunitinib treatment (59 of 64 patients). Among the 36 patients who achieved CR with TKI alone, eight continued TKI treatment after CR, whereas 28 stopped treatment. Seventeen patients who stopped treatment (61%) are still in CR, with a median follow-up of 255 days. Among the 28 patients in CR after TKI plus local treatment, 25 patients stopped treatment, and 12 of these patients (48%) are still in CR, with a median follow-up of 322 days. Conclusion: CR can occur after TKI treatment alone or when combined with local treatment. CR was observed at every metastatic site and in every prognostic group.