The invention provides new compositions or combinations thereof for the treatment of cancer. More specifically, the invention provides compositions or combinations thereof for cancer treatment including a high-fat diet. Specifically, the high-fat diet is characterized by having approximately 120 g/day or more, or approximately 70% or more of the total daily energy, from fat, based on a real weight of 50 kg. The diet is preferably a carbohydrate-restricted high-fat diet, and more preferably provided by a ketone formula and/or MCT oil. The dietary therapy by a high-fat diet of the present invention is provided along with surgical treatment, chemotherapy or radiation therapy, or combinations thereof.