Metastatic clear cell renal carcinoma – an unusual response to Temsirolimus in second line therapy

Renal cell carcinoma (RCC) represents 3% of all cancers, with the highest incidence occurring in the most developed countries and representing the seventh most common cancer in men and the ninth most common cancer in women. The understanding of the tumor molecular biology and the discovery of new drugs that target molecular pathways have increased the arsenal against advanced renal cell carcinoma and improved the outcomes in the patients suffering from these affections. Studying the molecular signaling that controls the tumor growth and the progression has led to the development of molecular therapies targeting the vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) pathways, resulting in a significant improvement in the overall survival and quality of life. Sunitinib represents an inhibitor of VEGFR 1-3, c-kit, FLT-3 and PDGFR. We present the case of a patient with metastatic clear cell RCC with a treatment effect following sequential VEGF and mTOR inhibitor treatment. Under sunitinib treatment, the patient had a progression free survival (PFS) of approximately 9 months, similar to the PFS observed in clinical trials. Sunitinib was well tolerated by this patient. Temsirolimus, an mTOR inhibitor, is currently only approved for the first-line treatment of mRCC patients with poor prognosis. This study analyzes a treatment effect of second line temsirolimus in a patient with metastatic renal cell carcinoma (mRCC).