The BBC article (http://www.bbc.co.uk/news/uk-scotland-22015175) states that he may undergo chemo once his jaundice clears up, so it doesn't seem like he's planning to just go entirely quietly, but the reality is that he has to make a tradeoff between possibly making his last months or year (or hopefully a bit more, if we're lucky) total agony to extend it by what is unlikely to be more than months, or try to be comfortable for as long as possible.

Cancer treatments is still ridiculously primitive, unfortunately, largely boiling down to doing lots of damage while trying to keep the patient alive longer than the cancer.