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Christina Applegate

Emmy-winning actress Christina Applegate was diagnosed with the disease when she was 36. Applegate, now 40, is cancer-free after undergoing a double mastectomy and has launched her own foundation dedicated to the cause called Right Action for Women. The "Up All Night" actress, has said that her secret to getting through the tough times was laughing - a lot. "I have to or else I'll just cry all the time," she told Us Weekly. "Laughter is so healing ... I think that it frees up your body to heal, too. Humor has always gotten me through the toughest of times." (1/6/2012)

Stars who beat breast cancer

Christina Applegate, Giuliana Rancic, and Sheryl Crow are just some of the celebs who've persevered — and in many cases thrived — despite the heartbreaking diagnosis of breast cancer. As we celebrate National Breast Cancer Awareness Month this October, check out some of their stories.