How can a terminally ill cancer patient survive without eating? for how long?

Cancer and survival: There are many metabolic things that happen as we begin the last stage of our lives. There are factors that are produced that result in cachexia, which essentially does not allow nutrients to be processed. At the same time, with lack of nutrition the body redistributes nutrients to just essential life-maintaining functions, thereby decreasing the amount of calories needed to survive.

Yes: You can prolong life by taking peanut butter paste every 2 hours a tiny amount- research on somalian malnourished kids worked like the above.