Do I have to keep relation with my rude & cruel atheist brother?

My elder brother is an atheist and so much rude & cruel to us that sometimes he even beats my parents specially my mother is the victim! You can't imagine what he has done to my family. I don't want to mention these scenarios , just assume that a 25 years old strong healthy sound minded person (atheist) who have no fear of Allah and several times he had thrown away the Quran, tore it off and disgraced it! What else can he do to us? When I close my eyes and think about him I see nothing but extremely bad memories! we're the victim of his oppression since 2011-12! So my question is short & simple: **Is he still considered as my family member? *Do I have to keep the relation with him?***