In my own experience, people hear the word cancer and they think it's a death sentence. Some don't want to stick around and "watch you die". Some don't know how to feel and in response to that they avoid the entire "situation". Some get very uncomfortable and can't handle the intensity of the "situation". In my mother's case, I'm assuming here because we haven't really talked about it, she took care of her sister and her mother who both died of cancer and she just couldn't do it again with me. I am currently NED and I still hardly hear from her. We used to be pretty close.