Julie, 70, was diagnosed with bowel cancer two years ago, while filming The Secret Garden and has now been given the all-clear.
However, she fears it was the stress of her career that could have caused the illness.
Speaking to The Times, she said: "The oncologist said to me, 'What do you think has caused the cancer?' And the first thing that came to my mind was acting.
"Acting caused it, because of the way I approach it - I have to be totally in it. It's very stressful. You're being judged. It's a stressful job and I don't sleep when I'm working. It's not good for me."
When Julie was asked if she had quit, she said: "After the operation I thought, 'I don't want to work again'... Unless it's another Mamma Mia."
Julie first revealed her diagnosis earlier this year, while chatting to Victoria Derbyshire.
The Secret Garden actress told BBC's Victoria how she had visited her doctor following indigestion and discomfort one year earlier, but returned after suffering with stomach pain and vomiting.
Recalling how she was then given a referral to a gastric surgeon as well as a CT scan, she explained: "[The doctor] said, 'sit down'. I said, 'yeah, what's up?'
"And he said, 'we've found an abnormality in your intestine'. I said, 'right, what is it?" He said, 'well, I'm worried it's cancer'."
Julie explained how she returned to her husband, Grant Roffey, who was waiting in the car.
"So I came out and then Grant was waiting in the car because he'd taken me," she continued.
"I said, 'they're worried it's cancer'. I'll never forget his face. And tears came into his eyes. And I thought, 'oh Grant!' So then I worried about him."
Following the news, Dame Julie explained she had surgery - with "30cm taken out of [her] colon" as well as chemotherapy.
While a third Mama Mia movie has not yet been confirmed, we've got everything crossed (now more than ever!) that it will happen.
Recently, creator Judy Craymer revealed that hopefully, there will one day be another film - as it was always "meant to be a trilogy".
Sounds very promising, doesn't it? Make it happen Universal, please!
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