Who do I report abuse and neglect to?

My nephew Steve is in the last stages of cancer, he's not able to take care of himself anymore, but his wife is abusing and neglecting him. She won't cook for him and she won't buy food for the house, he's lucky to find a cold hotdog in the refreigerator. His wife is an alcoholic, she has wild drinking parties and buys steaks for her mom, sister and her 2 grown kids and her friends, but not for her dying husband. She used to make him have supper ready every night for her and clean the house and do the laundry and if he didn't, there was hell to pay when she got home. He finally got so sick he wasn't able to do it anymore. She's always gone to winery or on trips with her family and friends or at a bar or off on shopping excursions, she's never there to take care of him, she acts like she hates him. She won't let his family come over there to help very much, she runs them off because she wants to run around and not be tied down taking care of him, he gets in her way cause he is sick and dying. She gets mad when he wants to go to the hospital and get the fluid drained off his stomach because he's having trouble breathing because it interferes with her plans to go to the winery with her friends or have a party for her spoiled kids. She has taught their 2 grown kids to treat him bad to, lots of disrespect. His son told him one day, I'm sick of you always talking about your cancer, I don't want to hear it no more. If his dad ask him for any kind of help at all he says no. His daughter got mad because he told her I can't clean your room and make your bed no more, you and your brother will have to do it yourself now and they got mad and said, we don't have time and slammed out of the house. They don't have time because they are too busy going partying with mom or on dates or playing on the internet in their bedrooms. None of them will help him or cook for him or clean for him, he has to take care of himself and he is so weak, he usually sleeps alot now. They have even posted pictures on facebook of some of their parties out on the deck while he lay upstairs in bed all alone. His wife says he makes her look bad, so she won't let him go to the hospital when he needs to, and she won't let anybody in his family help him either. She knows how to fool hospice to, when they come in on a Monday or Tuesday to check on him, she makes sure she is there so they will think she is taking care of him and that somebody is always with him, but then she leaves after they leave. When Steve's dad or sisters insist on going over once in a while to help him and check on him she tells them no her sister will be there or her mom but she lies they are not always there when she says they are, and if they do finally come in once in a blue moon, they play on the internet and they won't cook for him at all, he has to try and get something like a cold hotdog himself. Steve has told his wife he would rather his family sit with him but she says, no! He said he don't like her sister coming cause she brings her crying, screaming baby and she just plays on the computer and he said he's not up to that, but his wife don't care.She is very good at tricking people like hospice and his cancer doctors because when he has to go to the hospital she goes with him only so his cancer doctor will think she is there for him, but then when he goes home, she is gone again. She told the hospice nurse that she was thinking about working nights and being home days with him and when Steve asked her if she would, she said, No! It's like she taunts him and she is a pathological liar, it's got to always be only about her and what she wants. She always brags that she is sooo very rich cause she works as a top administrator at a big hospital in Missouri, she used to work in another big hospital in the baby department but they fired her for some reason and somehow she got a huge severance pay and she said they are not allowed to talk about it, plus they helped her get another job at this other big hospital. She thinks because she is so important that she can treat people how ever she wants, ask her employees under her, they are afraid of her. Steve has been to Missouri Baptist and another hospital to get the fluid drained, I can't remember if it was Barnes or a different one, she said she don't want him in her hospital, it will make her look bad. I feel like she is hiding things. Steve usually takes it no matter how bad her or the kids treat him, because he loves his kids and he's too sick and weak to fight with them, and because he don't have a job anymore, she makes all the money and he don't know what he would do cause he don't want to be a burden to anyone else. Steve has always worked and been a wonderful loving husband and father, even his boss said that he had been a great employee, but they had to tell him to go home and take care of himself. I think her and those kids are wanting him to hurry up and die. I want to remain anonymous or it will cause family problems.