How do you treat metastatic renal cell carcinoma with unclassified histology without sarcomatoid features?

There is limited data on optimal treatment of advanced non-clear cell RCC in general, including unclassified RCC. I have summarized the available data that I am aware of:

• The phase II study ASPEN randomized advanced nccRCC patients, including 20% with unclassified RCC, to sunitinib vs everolimus. Of...