Slow and steady wins the race: practical (and philosophical) considerations of treatment activity evaluation when novel anticancer agents just slow neoplastic progression.

Antineoplastic Agents; therapeutic use, Carcinoma; Renal Cell; drug therapy/secondary, Humans, Kidney Neoplasms; drug therapy/pathology, Niacinamide; analogs /&/ derivatives/therapeutic use, Phenylurea Compounds; therapeutic use, Sirolimus; analogs /&/ derivatives/therapeutic use