My friend tells us all in a discord chat that he has stage two brain cancer, this is after a month of him knowing us at most

He said he get brain cancer due too ionising radiation but what's confusing us is the fact he said he was exposed to this radiation on his trip to keiv almost 2 years ago and he might have gotten too close to Chernobyl, incase anyone doesn't know, Kiev is 100km away from the city in which the catastrophic event took place and the blast radius was 30km wide. I know its horrible to think someone would lie about something as serious as this but the holes in his story keep widening and I don't want to be friends with someone who would lie about this. Just one last thing, we started talking to him a month ago, and somehow he's saying this new stage two cancer has shown up in the 2 weeks we haven't heard from him