Kyle applies medicine and jokingly plays around with Adam's back wound. Seth Rogen did the same thing to screenwriter Will Reiser, who was diagnosed with cancer in his early 20s.
When Adam is listing things he has never done, one of them is that he has never visited Canada. That scene, as well as the majority of the rest of the movie, was shot in Canada.
When Adam tells Kyle he has a tumor, Kyle says, "Well are you going to be okay?" and his mouth doesn't move, then after that he says, "What are your chances?" and it almost overlaps.
Kyle, from most of the incidences in the movie, can be seen in taking advantage of his cancer fighting friend to get laid. On the other hand he was the only person whose behavior did not change towards Adam, even after knowing the disease. He helped Adam to get laid, see the world and even drive a car being a funny make-a-wish for him.There is also the incident were Adam discovers the book "Fight Cancer Together", illustrating the fact that Kyle all along tried his best to help his friend through this rough period of his.