Who you tell is up to you - no one, with the possible exception of your children, has a right to know. But I was happy to tell anyone who asked - briefly and then move on, I found it a fairly monotonous topic pretty quickly. I chose to tell my staff and director at work - I know this can be tricky for some, depends a bit on your work relations. My director could not have been more supportive - I took little time off but she was happy with anything I wanted. My main concern at work was chemo brain - my staff were all requested to let me know immediately if I made no sense. Which caused some hilarity - I was fine but oh boy, was that a tempting offer! Laughter is excellent medicine.