- Patients must have histologically or cytologically confirmed renal cell carcinoma that is unresectable and/or metastatic; patients with collecting duct carcinoma, oncocytomas, or transitional cell carcinoma are not eligible; patients with sarcomatoid renal cell carcinoma are eligible, but those with pure sarcomas are not; histologic documentation of metastatic disease is not required; clinical confirmation, but not pathologic staging, of metastatic disease is required