I just started a new job and had the same 'do I tell them' worry. I decided to tell them in the interview IF they asked a question that actually related to it some how but otherwise not to bring it up myself.
Funnily it was their very first question! I had left my old job as I was just completely burnt out after working though treatment. I had an almost 4 month break before applying for this new job and the gap on my resume was what they asked about - specifically why did I have a break/leave the old job.
I told them that I had a pretty intense year last year and went though BC treatment. I took some time just to refresh and it was wonderful. I am recharged and feeling good. I made a point of saying that it is in the past and I dont want to dwell on it just move forward.
At the end of the interview they thanked me for being honest. I think seeing that it didnt hinder my ability to do the job and that I was eager to simply 'get on with it' painted the whole thing in a better light.
I got the job and they havent treated me any differently which was a minor concern.
All the best with all your work stuffs! :)
