Has anyone had a family member go through a cancer fight with no insurance?

First off, I don't want this to turn into a healthcare political debate, so please don't do that.

My sister-in-law has cancer. We will know in the next couple of days what type and how aggressive, but we are already lining up the things necessary to help and support her.

I just learned that she has no insurance. I've had a number of family fight cancer. Some won, some lost but they all had insurance. I haven't had one day in my adult life when I didn't have insurance, so I'm really not knowledgeable on how you approach what is likely to be a 6 figure cancer battle without insurance.

Does anyone have any experience with this? Knowledge of services available etc.? She lives in Northwest Arkansas right near the border of Oklahoma and Missouri (the Bentonville/Rogers area). I'll be heading there this week but I'm trying to do research now on what we will have to do to get her treatment.