Shannen Doherty has offered her support to Michael Buble following his son's cancer diagnosis.

Shannen Doherty

Shannen Doherty

The 45-year-old actress - who is currently being treated for breast cancer - advised Michael and his wife Luisana Lopilato to "stay positive and trust in your doctors" as they help son Noah, three, through his illness.

Speaking to Entertainment Tonight, Shannen said: "I can't even begin to touch that one to be honest, because it's a three-year-old. I would imagine your child having cancer is devastating as a parent.

"Just trust in your doctors. Make sure you have amazing doctors, a great team and know that organisations like the American Cancer Society, Stand Up to Cancer, they are doing so much good for cancer. And [there is] so much research that we have much better chances now. Stay positive.

"That positivity, that outlook on life that you can get through something, it actually does get you through."

Shannen's comments came after Michael announced the sad news on his Facebook page last week.

He said: "We are devastated about the recent cancer diagnosis of our oldest son Noah who is currently undergoing treatment in the US. We have always been very vocal about the importance of family and the love we have for our children.

"Luisana and I have put our careers on hold in order to devote all our time and attention to helping Noah get well. At this difficult time, we ask only for your prayers and respect for our privacy. We have a long journey in front of us and hope that with the support of family, friends and fans around the world, we will win this battle, God willing."

But friends of the couple - who also have an eight-month-old son Elias together - say Noah is a fighter.

An insider told Us Weekly: "They are really sad but hopeful. They immediately got him very good care and they are hoping and praying for the best.

"They are getting him the best doctors around. It's really heartbreaking. This was a real shock, but they are doing everything they can.

"They're staying positive and Noah is a fighter."