I don't think there is just one answer to this depending upon the person and their values, beliefs etc. Sometimes it seems to me, it is enough to just have more good days than bad. My person's is not curable but they are treating it for quality of life. That can be the bigger quality of life picture or the smaller one. Enduring the treatments thus far has allowed my person to still work, do some things she enjoys, travel for work and vacation overseas, etc. even though she has also been very sick and endured painful miserable side effects, is always physically exhausted and so on. A weighing of benefits I would say.