Hi, Valerie -- I see that you reiterated one of your points from your OP, about your FH not having anyone in his family who has had cancer. You know, people have strong reactions to cancer. I was widowed due to my late husband having a rare (and misdiagnosed) form of cancer. My present husband lost his wife to a cancerous brain tumor. Years earlier, the mom who raised me died of ovarian cancer. The "C-word" is a very scary thing for many people.
Some people respond to that by wanting to be active, as you are, in raising money etc. Others just don't want anything to do with it. To be honest, I tend to be more on the latter side, while my DH is more of the former. If I wanted for us to walk in our local Relay for Life, he'd be glad to do so. Since I am not comfortable doing that, we just make a monetary contribution to a friend who walks in it. It's not that I don't care about people who have cancer, I do. I just don't like the hoopla atmosphere of the Relay for Life. That's just me.
Yesterday my DH was at cardiac rehab, where they have TV sets by the treadmills, and was watching a ball game while he exercised. A lady on another treadmill was watching the news about Ted Kennedy's brain tumor. She looked over at my DH and said, "I can't believe someone would be watching a ball game when this is on the news!" A nurse came over to her and told her to be quiet and mind her own business because some of the patients in the room had had personal tragedies due to cancer and did not necessarily want to be reminded of it.
I don't know if this sheds any light on what may be happening in your relationship, but I hope it may be of some help.