Temsirolimus in metastatic chromophobe renal cell carcinoma after interferon and sorafenib therapy.

Chromophobe renal cell carcinoma (chRCC) is a common subtype of renal cell carcinoma (RCC), occurring in 6-11% of renal carcinoma patients. Limited clinical trial data have shown minimal activity with cytokines and chemotherapy, although small-molecule inhibitors of the vascular endothelial growth factor and platelet-derived growth factor pathways such as sunitinib and sorafenib, which are associated with significant clinical activity in clear-cell RCC (ccRCC), have been associated with a 25% response rate in chRCC. The mammalian target of rapamycin kinase inhibitor temsirolimus demonstrates good clinical activity in ccRCC patients with poor prognosis, with further data suggesting it is an effective treatment for all RCC tumour histologies. This report describes the case of a patient with chRCC who experienced rapid improvement in his general condition and stable disease on treatment with temsirolimus, following disease progression on interferon alfa and sorafenib treatment. This case report suggests that temsirolimus is an effective and appropriate treatment for this RCC tumour subtype.