The war with cancer looks different to different people and the outcomes vary as well. Apparently Zach just passed away.
He says near the end of this video that he'd like to be remembered as "a kid who went down fighting, and didn't really lose..." Ultimately with something like cancer, that's about how it goes. Fighting comes in the form of smiles and hope and a wanton disregard for death as an entity of defeat. It sounds like this kid succeeded. Good job bro.