Help, i don't know how to handle the sadness thats coming.

Your comment was that you had heard that she has Breast Cancer.
Agree with @primek unless she shares that information with you it is not for discussion about her condition.  
She is there, at this appointment, in her professional capacity and there for you.  
Concentrate on yourself and perhaps look at her with admiration in that she is able to put her diagnosis to one side to concentrate on you and her other patients.  Try and hone in on what the appointment is about, you and why you are there, she is there to help you

Take care of yourself 
.

Thank you wondrous ladies for these articulate helpful words. I’m going to read them as I tremble in the waiting room in the morning. I have gotten way way way too good at shoving my emotions down and surviving and being in a fair bit of denial about things for a while now. So my fear is that I’ll just completely come undone and she will be upset, and I’ll feel guilty and ugh....you’re right @primek I am trying to predict everything aren’t I?! Brain is doing a number on me big time. 

She must be just even more extraordinary than I already knew - to be a doctor to women with the same illness, and be strong enough to face up to that, in a professional setting....I am just in awe of that. And the more I am blown away by that strength, the more sadness I feel at how shit it is that someone so awesome has to suffer. I don’t know if I’m explaining it right 😕 but it’s a biiiiiig basket of mixed emotions tonight, and going in will be bloody hard. I hope I can be as strong as she taught me to be. 

Hi Summer. If you haven't already, spend some time reading Liz O'Riordan's blog. She's a breast surgeon who got breast cancer. It's a cracking good read. She's a good writer and her insights from both sides of the fence are excellent.

http://liz.oriordan.co.uk/Blog/

@Sazbe @JoeyLiz and @kezmusc may have some thoughts on this that could assist.

My feeling is that if she's at work she must want to be. So like @Annski says, give her the emotional space to be a doctor for you. Depending on your relationship you could tell her that you are upset and struggling with the brutal unfairness of her situation.

I understand that you don't want to load her up with it. Maybe ask someone who works with her if she's understanding of how her news affects her patients? Either way, some deep breaths before you enter the room.

It's a very difficult situation. I'm tremendously fond of my BS. If I found out he had cancer I'd be very upset.

Don't panic. Try to get a good night's sleep so you've got some reserves to draw on tomorrow. K xox

Number 1...don't overthink it.
You are trying to guess what will happen, guess what she'll say...guess what you will feel.
She might just want  to get on with business and not discuss her treatment.
I know laying on the gurney waiting for my port to be put in and my pre op nurse...secretly showing me her scar and telling me...it's going to be okay...I'm 6 years on...was the best thing that happened. I've met many people over the years..and counselled people myself who have cancer. What it does mean...is they will get it...they'll get the fear...the will understsnd side effects and the frustration...like no other Dr might.  

So just go in...like any other day ...and try not to tilt your head and do the "how are you" thing we hate. Just say good morning...and  see where it goes. Kath x

@"Summer Prevails" maybe if you think about how you can make it easier for her - it must be difficult enough for her to process but she is a professional and she must want to go on in her occupation. Perhaps you can both just be together in your respective roles while offering some sense of kindness and compassion to each other, recognizing what you are going through together as companions on a very hard journey. You will need to face up to your grief and anger but tomorrow's appointment probably isn't the best time for it. Best wishes and here's hoping you can find the strength to make it easy for you both.