I used to hide the fact that I had cancer. There are people who knew me for decades before I told them about my thyroid cancer diagnosis. When I was diagnosed with breast cancer I was a bit more open about it but I still kept it private to an extent.
I think I cared more about it when I was working full time. I didn't want any potential employer to know that I had cancer because, even though people are not supposed to discriminate they do. If you are looking at two potential employees who have the same credentials, the one with a history of cancer will probably not be selected because they might 'get sick again'. This is a reality all of us cancer people face regularly.
Now I don't work any more. I have told more people about my cancer history than not. I don't really care if people know. I'm am doing okay these days mentally so I am not stressed about it.
My cancer history, and other chronic medical crap, isn't going away anytime soon so I just need to be me. Hiding it doesn't benefit anyone. Talking about it and recognizing it as the part of my life, that it is, is much healthier as far as I am concerned.