I held back from telling anyone other than my closest friends & family until after Christmas (diagnosed 4/12). I didn't want to spoil the day, the festive season, and by that time I knew that the cancer hadn't spread so I could be reassuring with the news. Plus my son turned 18 between my wide local excision and re-excision. There was no way I was going to spoil his day and party. One good friend was on the trip of a lifetime with her husband and children in France and the UK and I asked that the news be kept from her until she got back.
Lots of friends asked me if it was 'a secret'. My sister had placed enormous restrictions on what we could say about her health during her illness. Basically we were instructed to lie a great deal. It placed a great deal of strain on the family, especially my parents with whom she lived. I was determined to not repeat that, which is one of the reasons why I have been so open. So no, never a secret. I recognised that my friends would need to be open to seek their own support.