I am really sad to hear this.

I have watched her on tv since I was about 12. Beverly Hills 90210 was really popular at that time so everybody watched it and talked about it the next day at school. I also watched Little House on the Prairie in reruns about the same time. Anyway Brenda was my favorite 90210 character and the show was never the same after she left for London.
I listened to a couple of Shannens podcast episodes earlier this year. I think she was so brave about her cancer battle. It's sad but not unexpected it ended like this.
Cancer really sucks and it affects everyone, the person who gets it and their loved ones. I want to offer my condolances to Shannen's family, friends, co-stars and fans.
I especially think of her mother and also of SMG since she was one of her best friends.
Rest in peace Shannen you'll be missed.
