Shannen Doherty, 49, is in the midst of a battle with stage IV breast cancer, and she has the full support of her Beverly Hills 90210 co-stars. “I texted with Shannen last week,” Ian Ziering told HollywoodLife EXCLUSIVELY while promoting his show Swamp Things, which premieres on Oct. 6 at 8:00 p.m. on the CW. “We don’t always talk about, ‘How are you doing, how are you feeling?’, but I can tell from our text messages that she’s as feisty as ever and Shannen is resilient.”