Hey Hey It’s Saturday star John Blackman has revealed his life-threatening bone cancer diagnosis.

Blackman is best known for voicing puppet Dickie Knee on Hey Hey It’s Saturday. The TV personality previously battled an aggressive form of skin cancer four years ago which led to him undergoing surgery to replace his chin with a leg bone.

The 74-year-old revealed the sad news on Facebook. “Four weeks ago, I was diagnosed with a very unexpected bone cancer on the top of my noggin and the possibility of brain cancer beneath (yes, I actually do have a brain),” he wrote.

“This was the same aggressive cancer that took my jaw four years ago,” he added.

“Happily, the cancer (if there is a happy side to cancer) was spreading up and down and not in multiple directions. This could have made surgery improbable.”

Blackman went on to say that he has already had surgery at The Alfred Hospital in Melbourne and will undertake six weeks of radiotherapy, starting next week.

“Following PET and CAT Scans and a radioactive MRI, my plastic surgeon, Frank, consulted with my neurosurgeon, Patrick, and together they devised a plan of attack. Both are eminent in their fields and professionally precise who have worked on several similar surgeries together. They were very confident of success.”

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“The cancer-infected bone has gone and been replaced with a titanium mesh cover; a skin graft has replaced all of the skin on top of my head; and brain biopsies taken during surgery are clear,’ he continued.

“A great result with enormous gratitude to the dedicated doctors and nurses at The Alfred – true heroes each and every one of them.”

While Blackman’s previous battle with cancer was successful, he previously told Nine’s A Current Affair that the surgery could potentially end his TV career.

“[My surgeon] said, “Well, just get prepared to not be able to do all the things you’ve been able to do for the past 50 years,” which is a bit of a kick in the guts,” he revealed.

“To perform, you have to look good, you have to sound good, you have to sound confident and be confident. I just won’t be able to do that anymore. Life without doing that is just so alien to me. I mean, I don’t know what I’m going to do.”

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