Just found out my 72 y/o MIL has cancer in her kidneys, what are her options if any?

I would discuss this with her oncologist. I am sure your family  is in shock after getting this terrible diagnosis. Is it in one or both of the kidneys? 
I do know in my experience as a nurse I’ve seen people with kidney cancer have the kidney (s)removed and go on dialysis & do ok. But not knowing your MIL, I can’t say if this would be an option. At least now with a diagnosis they can prescribe medications to improve her blood count, get fluid off & control her BP. 
I suggest getting a list of questions together written down and discuss with her team of doctors.
So sorry about your MIL.

I believe everyone should have the right to choose whether or not to go through treatments. I had a friend with kidney cancer who had one kidney removed. He was supposed to go back for yearly check-ups, which he blew off. Sometime later, the cancer was back and metastasized. He went through weeks of radiation that just about took him down. He lived another five years or so, but his final years were pretty miserable. He was younger than your MIL.

Quality of life with each option should be discussed and researched. Sometimes medical professionals don't have realistic expectations about their patients. My dad's oncologist wanted him to undergo six weeks of radiation for his lung cancer. My dad was 91. I told the doc there was NO way we were putting my dad through that. So he had two weeks of radiation to keep him comfortable. He had large burn areas on his sternum after just two weeks. I can't imagine what six weeks would have done to him. My dad lived to 92 and died comfortably.

Is there someone like a pastor or rabbi who could speak with your MIL about her desires once you know her options? It sounds like her health has made her life less than pleasant. So please let her decide (without family pressure) what she wants to do once she hears her options.

How about getting husband to talk to her about palliative care with her doctor? That's medical care that is designed to only provide comfort and not attempt to cure something life-limiting like 4th stage cancer. She could receive pain meds, surgery if it would help her pain, etc. If she's lost the will to live, it's probably because she's in a lot of pain. If her pain were relieved, she might find the fight again, and want to fight longer!

I'm sorry to hear the news about your MIL. This has to be hard to accept, especially, when she had thought it was something else. I don't know anything about her condition. I just wanted to chime in with words of support. Let us know what you find out and how she's doing.

I'm sorry about your friend and dad, @blannie! I honestly believe that if she were offered treatment, which I'm sure she has been, she won't want to do it. I mean, I can't speak for her, but it seems like something she would refuse. She's also VERY weak. Before she went to the hospital, you couldn't even lift her. It took three male paramedics to lift her out of the chair. She was dead weight, and she could barely lift a spoon to eat or a cup to drink. I'm not sure her body could physically handle taking on a kidney removal surgery and/or dialysis. She's in really bad shape.

I don't think anyone is trying to pressure her. Obviously, the family is sad about what's happening, but you can't force someone to want to go through with something like that. We'll see what happens.

She's not a religious person whatsoever and I feel like the only time she'd have a priest come in and speak with her is when they read her last rites. That's how my grandma was before she passed away. It's certainly something to discuss with her, though.

There is a very good book called 'Taking Charge of Cancer' by David Palmer MD PHD, written 2017, which is written for exactly your situation. It explains options, how to read reports, how to support and deal with medicos, etc. Well worth the money.

So, update, the doctors did offer her chemo and dialysis, but they don't think her body is in any shape to accept the treatment because, as mentioned, she's in extremely poor health. And she's deteriorating at a rapid rate. They're also waiting on results of a biopsy they did on her kidneys and liver. I always assumed they did the biopsy BEFORE the cancer diagnosis, but I don't know. They're giving her medicine to keep her from being in pain, but I really don't think she has much time left.

@Countrymouse I don't think she wants to keep fighting, honestly. She was in terrible spirits yesterday, according to my husband. She was also in a state of confusion. She told him and my FIL to "turn off the washer, to pull the knob to turn it off", so her mind is slipping. They are giving her pain meds to keep her comfortable, but that's all they can do, she's refusing home care, hospice, etc.

I honestly can't blame her. The diagnosis of course will have come as a blow; but besides that, and going on for a lot longer, poor renal function makes a person feel terrible. She must feel just so *ill.*

I'd question her detailed mental capacity when it comes to patient's consent issues, but not how dreadful this is for her. I'm so sorry for what you're all going through.

I am sorry to hear about your MIL. I hope your husband finds a good hospice provider. Will she go home with hospice or go to a hospice center? I have read on this site that if in a hospice center she may be charged for room & board as Medicare covers hospice services but not room & board. Just a FYI should FIL have limited funds.