[Interferon alpha and half-dose sorafenib is an effective treatment modality for interferon alpha-resistant metastatic renal cell carcinoma: a case report].

Metastatic renal cell carcinoma is notoriously resistant to chemotherapy and radiotherapy. Immunotherapy with interferon alpha is widely used for the disease, but its treatment effects are poor. A 69-year-old Japanese women presented with gross hematuria. Imaging studies revealed a left renal tumor, 12 cm in diameter, and multiple pulmonary and hepatic lesions. No abnormal laboratory data were observed other than anemia with Hb 9.2 g/dl. Performance status was 0. She underwent radial left nepherectomy. Pathological examination showed clear cell renal cell carcinoma with moderate histological differentiation (grade 2) and microscopic vessel invasion; pT3aN0M1 (Pul, Hep). Memorial Sloon-Kettering Cancer Center classification was an intermediate risk due to anemia. She received interferon alpha, 5 million IU three times per week, postoperatively. In three months, hepatic lesions rapidly progressed although there was no interval change of pulmonary lesions. Then, the patient received interferon alpha at the same dose as described above and half-dose sorafenib, 400 mg per day. Grade 2 hypertension was under control by calcium channel blocker and the hand-foot syndrome was not obvious. No other grade 3/4 drug-related adverse events were observed. In one month after combination therapy, not only pulmonary lesions but also hepatic lesions were smaller. She has received this combination therapy with stable disease for six months. Performance status was 1 with grade 1 fatigue. The doses of this regimen may be tolerable, and might be an available treatment option for interferon alpha-resistant advanced renal cancer.