There are no set rules of etiquette, and do whatever you are comfortable and can live with. I've seen some "How to tell others about Cancer" suggestions either here, elsewhere, maybe ACS, but a quick search will show them, plus many may follow and offer their thoughts.

I believe most people are supportive, although some may not be, and ran into a few of them, and some patients have to be carefull with thier employment as far as benefits, medical etc. It is a buisness after all, and most have some type of employment rights. I always found honesty to be the best policy with your employer. I also found support in people I least expected, even strangers. As time went on, I'm almost 5 years from my original diagnosis, still battling this disease 7x, and many from the start I seldom hear from now, even family, so time is an aspect too.

I was, and still am a private, straight forward guy, and rarely ask for help, not here maybe lol, and did not belong to Facebook or any other internet social or cancer groups, including here until after a year dealing with cancer. If I can count on one hand who I call my friend that's a lot, and like it that way too. As far as work, I was hospitiized for an extensive period, so that took care of business of who telling who what. I only answered to one person, and didn't have to explain much to anyone, never did anyway lol, and there is HIPPA too, but once one person knows, everyone does, usually. If I said anything, it was on a need to know basis or those who were genuinely concerned, visited me.

I hope this helps.