Not many people can understand what you're going through by losing a brother. I do consider that life itself is meant to end, and instead of grieving, we should celebrate their lives(ones we lost).
I could say I am sorry, but that will not bring him back or make you feel better. I do wish you all the best, though. I think that your brother found peace; fighting cancer for five years isn't your day by day job - that's something respectable.
Take care!