However, the news still came as a huge shock to her and her family, including her husband Grant Roffey.
She recalled: "I'll never forget his face. Tears came into his eyes."
Doctors actually discovered two primary tumours in her large intestine.
And Julie - who has starred in Mamma Mia, Billy Elliot and Educating Rita - has now admitted to doubting whether she'd survive her cancer treatment.
The actress - who had "30cm taken out" of her colon during surgery - confessed to thinking: "I may not come round from the anaesthetic."
Julie also revealed the surgery left her feeling "exhausted" and "a bit low" in the days after she went under the knife.
She said: "I said to the night nurse, 'Is Love Island on?' - because we were talking about it - and we watched it together. It was only a couple of days later I thought, I feel exhausted, and a bit low actually."
The Educating Rita star subsequently went through chemotherapy, and is now "clear" of cancer.
Julie shared: "I've just had a scan, and I know that [I'm] clear."
The acclaimed actress added that she's currently doing "really well", in spite of her health scare.