If I remember correctly, your brother had a tumor on his lung, is that correct? I'm so sorry to hear it is malignant. I'm also very sorry to hear your brother has been abused. I hope there is some way to get him away from his abuser.
I know we cannot control others, but that doesn't make it any less sad when someone we love isn't taking care of themselves. My thoughts and prayers are with you and your brother. (((HUGS)))