Applegate has since gone on to become engaged to musician Martyn LeNoble, and the pair welcomed daughter Sadie Grace into the world last month (27Jan11).
Now the actress has spoken out about the birth for the first time, revealing becoming a mum has made her life "so much better".
She tells People.com, "I felt my heart literally open up for the first time and like wrap itself around her. It was profound. And I'm more in love with her every minute of the day...
"I've had to talk about that word (cancer) more than I've ever had to talk about a word in my life. After a while you're like, 'There's got to be something else to me.'
"Yeah, now I'm Mom. She's healed me in so many ways. She's just made my life so much better. She's opened my whole soul."