Evidence and Clinical Relevance of Tumor Flare in Patients Who Discontinue Tyrosine Kinase Inhibitors for Treatment of Metastatic Renal Cell Carcinoma

In this report, we looked at the outcomes for patients affected by metastatic kidney tumors who discontinued treatment with antiangiogenic agents. We found that tumor regrowth after discontinuation of therapy was related to the reason for discontinuation: regrowth was higher in patients who discontinued treatment because of disease progression, and lower in patients who discontinued treatment because of a sustained response. Moreover, we found that the higher the growth rate, the shorter the survival. We conclude that discontinuation of antiangiogenic agents may cause an increase in tumor growth rate, which is related to patient survival.