I got to deal with NAMI a second time. They did follow the book, which in my case was kind of ridiculous. Get a weird pneumonia, end up on an ECMO machine and go into AFIB because of the meds they put you on for it, with nothing wrong with your heart? Mando six month wait. Which means nine months.Unfortunately, the most durable memory aviators have of NAMI is of the initial flight physical process, and the spectre of arbitrary diqualification. However, the interaction dramatically changes once winged. Almost any physical condition is waiverable for a designated aviator, if not immediately, at some point in the future once definitive treatment is rendered and recovery completed. Ultimately, as Gatordev says, take care of yourself.
Having seen enough of his responses, I'd vouch for @TimeBomb seeming to be a decent one! That said it's still a dangerous game to play; either admit your problems to your flight doc and get downed, or don't get treated. The good flight docs will keep you flying! But if it's a real problem your health is more important.
I've also been in a squadron with a "Powerball". So cancer is indeed waiverable.