Sam Neill Reveals He's Being Treated for Stage 3 Blood Cancer: 'Just Pleased to Be Alive'

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Sam Neill is opening up about his stage 3 blood cancer diagnosis for the first time.

The Jurassic Park star, 75, who writes about his journey with angioimmunoblastic T-cell lymphoma in his upcoming memoir Did I Ever Tell You This?, told The Guardian he's "just pleased to be alive." He has a rare form of non-Hodgkin lymphoma and has to undergo chemotherapy once a month, likely for the rest of his life.

"I can't pretend that the last year hasn't had its dark moments," said Neill. "But those dark moments throw the light into sharp relief, you know, and have made me grateful for every day and immensely grateful for all my friends."

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He learned his diagnosis after first experiencing swollen glands last March while doing press for Jurassic World Dominion, and began writing vignettes from his life while receiving chemotherapy.

"I found myself with nothing to do," he recalled. "And I'm used to working. I love working. I love going to work. I love being with people every day and enjoying human company and friendship and all these things. And suddenly I was deprived of that. And I thought, 'what am I going to do?' "

"I never had any intention to write a book. But as I went on and kept writing, I realized it was actually sort of giving me a reason to live and I would go to bed thinking, 'I'll write about that tomorrow … that will entertain me.' And so it was a lifesaver really, because I couldn't have gone through that with nothing to do, you know," added Neill.

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Neill noted that the book is not about his cancer, but the diagnosis does serve as a "spiral thread" throughout. "The thing is, I'm crook. Possibly dying. I may have to speed this up," he writes in the first chapter, according to The Guardian.

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Although Neill noted that his chemotherapy treatment failed, the new monthly chemo drug has prevented any cancer from returning.

Did I Ever Tell You This? hits shelves Tuesday, March 21.