FYI

Don't send me a "hang in there, I really hope you are doing well, x person told me your "situation"" message, because it's crude. Either you want to wish someone to get better or you don't. You don't wait for them to contact you and then decide hey I'll take the opportunity to tell them this because I am a lazy fuck and don't really give shit but want to seem like I do. Also it's called cancer, not "situation" I'm not fucking pregnant. Seriously, it better if you don't contact me at all. Less pretending.
Oh and while we are on the subject, if you know someone is sick and you genuinely want to tell them to feel better, do so. Don't think you are bothering them. I get that people feel weird about sick people, I get that, but an e-mail is not very personal but gets the message across just fine.