How would you treat metastatic pure tubulocystic renal cell cancer?

Tubulocystic renal cell carcinoma (tcRCC) is a very rare diagnosis--particularly metastatic tcRCC. To my knowledge, there are no clinical trials that have reported on these patients even in the basket non-clear cell RCC trials such as ASPEN (Armstrong et al., PMID 26794930) and ESPN (Tannir et al., ...