The 'Left Outside Alone' singer was told she had the illness in 2003 and when she was at her lowest the 'Rocket Man' singer devoted a lot of his time and energy to help her cope with her ordeal.
The 44-year-old musician will always be grateful to Elton for his support at such a difficult time.
She said: ''He is just a shepherd. He's a shepherd with music, he's a shepherd with ailments, he's just such a giver and he's my little angel. He's my fairy godmother, you know.''
The pop star appeared on UK TV show 'Lorraine' today (01.10.12) to support Breakthrough Breast Cancer's new Touch Look Check (TLC) awareness campaign to encourage women to regularly check their breasts for any changes to prevent the disease.
Anastacia can vividly remember the moment she was told she had cancer and she admits it felt like the world had ''stopped''.
She explained: ''I was so naive when I started in this business, even though I was older, I had no idea.
''I had never travelled outside of America, I didn't really realise the world was the world, I thought it was a globe in my school.
''So I definitely had a lot to learn about things and when I got diagnosed with breast cancer, the world kind of stopped for a minute.''
As well as the medical treatment she received, Anastacia also credits changes she made in her diet and lifestyle in aiding her recovery.
She said: ''Technically I really had to end up taking care of myself and I'm not the best at that ... It's eating right and taking care of myself and looking at things a little bit differently than I did before.''