Absolutely. Sometimes we should fight to make sure our loved ones get every bit of medical help they can. Other times we have to realize that they are not going to make it and give them pain relief and our love, while allowing them to go.
I despise the practice of assisted suicide (and the more common practice of killing through neglect) but when a person has a terminal illness it's OK to not take heroic measures.
In spite of some discomfort he's enjoying life as much as is possible for someone his age.