Shannen Doherty has revealed that she has been secretly battling stage four breast cancer for a year already. The star of Beverly Hills, 90210 and Charmed shared the heartbreaking news in an interview with ABC News that aired on Good Morning America on Tuesday morning.

Shannen Doherty: Her cancer is back

In the interview with ABC's Amy Robach, Doherty opened up about her illness. The actress was first diagnosed with breast cancer in 2015 but managed to fight the disease. Now, the cancer has returned but - until now - Doherty had shared the news only with her immediate family.

Shannen Doherty Cancer

"It's going to come out in a matter of days or a week that -- I'm stage four. So my cancer came back. And that's why I'm here," Doherty said. "I don't think I've processed it. It's a bitter pill to swallow in a lot of ways."

Shannen Doherty: "How am I going to tell my mom, my husband"

She shared her thoughts on her breast cancer's recurrence and how she has dealt and is still dealing with it: "I definitely have days where I say why me. And then I go, well, why not me? Who else? Who else besides me deserves this? None of us do," she said.

Beverly Hills, 90210 star Shannen Doherty fought cancer

"But I would say that my first reaction is always concern about how... how am I going to tell my mom, my husband."

Shannen Doherty: Watch her full interview here!

The actress also said why she shared the news in such a public way: "I'd rather people hear it from me," she said. "I don't want it to be twisted; I don't want it to be a court document. I want it to be real and authentic and I want to control the narrative. I want people to know from me."