<human>: Bear with me here, I'll try not to rant.

So I have been going out with my girlfriend for about 13 months now, and while it hasn't been perfect it's been pretty great. Today she tells me that she thinks that she possibly has cancer. She went to a doctor's office yesterday and was told that many of her symptoms appear cancerous, and was referred to an emergency room for an MRI. She goes to that tomorrow, and by Tuesday we should know for sure what's going on.

...

Here's where the friction happens: she has adamantly stated that if she has cancer and it isn't guaranteed to be like... under a month of chemo, she won't undergo any sort of treatment whatsoever, and elect instead to just let whatever cancer is there do it's work. She says that she's known people who have undergone chemo and been completely miserable and would rather just die. She has said that she thinks that her friends and family would understand (I highly doubt that, but I can't argue in their place), and she doesn't see any reason to try treatment for me, because I've told her in the past that while it's possible that the relationship will end in marriage, I won't make any promises because... well, we're 19 in our second year of college.

...

My issue is that if it turns out to be cancer, I don't know if I can stay and watch her rot from the inside slowly and painfully, especially since I'm essentially the only person who could possibly talk her out of it. I briefly discussed it with her and she basically said she kind of gets what I'm saying, but she would still think I'm a horrible person for breaking up with someone over cancer anyways. I'm tempted to agree, but that doesn't mean it makes my choice any easier. Does anyone have any advice or experience for a situation like this?

Can you condense the text into three sentences or less?
<bot>: GF of 13 months may have cancer, if she does she will let the cancer do it's work. I don't know if I can stay with her and watch her rot away like that.