Renal cell carcinoma has a poor outcome and since there is little to do therapeutically the researches tried an alternative approach to treatment of the cancer in vitro (in a test tube).
The researchers used menadione a synthetic vitamin K3 and D-fraction a mushroom extract. What the researchers found was that the menadione was able to reduce cancer cell viability by 20% while the D-fraction reduced it 20-45%. However the real results were seen when the menadione and the D-fraction were combined. The combination resulted in a 90% reduction in cell viability.
While these results still need human trials it does give hope that this combination could be a viable therapeutic modality for renal cell carcinoma.