50/50 is fifteen, and the thing that still separates it from every other film about a young person with cancer is that it is not trying to move you. It is trying to be accurate, and the accuracy turns out to be far more moving than the alternative would have been.
Will Reiser wrote it out of his own diagnosis, in his twenties, while working alongside Seth Rogen. Rogen then plays the friend, which sounds like a stunt and is not one. The humor here is relentlessly tasteless in the way that real friendships under real stress are tasteless, and that tone is not something you can assemble from research.
It nearly happened with a different lead. James McAvoy was cast and left days before production began, with his wife going into labor, and Joseph Gordon-Levitt stepped in with roughly a week to prepare. What he does with that week is remarkable. The performance is built almost entirely out of underreaction, a man being politely agreeable about the worst news of his life, and it sets the temperature for everything around him.
Jonathan Levine directs with almost no visual editorializing, which is the right call for this material. Anna Kendrick's inexperienced therapist is the film's second best idea, a professional who is obviously out of her depth and decent enough to keep showing up anyway. It holds a 93% on Rotten Tomatoes, which for a comedy about chemotherapy is its own kind of statement.
A hundred minutes, no speeches, no swelling strings at the moment you brace for them. Put it on with the person you would actually want sitting in the waiting room.
