I am sorry to hear about your uncle. I agree with everyone else, cancer sucks. When my mom was diagnosed I didn't live close by and couldn't be there for the day to day. I sent her a card weekly with a picture of the kids or a drawing they did. I also tried to mail the card on the same day every week. She told me later that this was the high point of her week. She would know what day that card was coming and it gave her something to look forward to.
If you are close, support for the caregiver is wonderful: House cleanings, meals, running errands (even some time off so they can get out of the house to run errands).
Good luck to you and your family.