Not always. I know a guy who has been living with stage four colon cancer for four years who, recently, has seen his tumors contracting for the first time ever.
So while I agree that you need to identify a point where you say, "Let me die in peace", I don't think that point is always the day you've been told you have stage 4 cancer. I'm not sure that the 20 days reference in the article is really time to come to terms with that.
This is truly the problem with evidence based medicine. You can say how a given treatment will impact a population (i.e. 1 out of 100 patients with stage 4 colon cancer will survive past 6 months) and say it's not worth it, but when you're talking to a single patient, you don't know what the outcome will be. Maybe the treatment will be in vain or maybe he or she will be the one patient that goes into complete remission.
So while I agree that you need to identify a point where you say, "Let me die in peace", I don't think that point is always the day you've been told you have stage 4 cancer. I'm not sure that the 20 days reference in the article is really time to come to terms with that.