The 42-year-old singer, who was diagnosed with the disease in 2005, told OK that she felt she had something to prove after her battle with the illness.
Minogue said: "There was the physical side of knowing your body’s been through a lot and dealing with those changes, but it was a real emotional challenge too.
"Performing again was what I had really longed for but I could definitely sense people were watching thinking, ‘Is she okay? Is she going to make it?'"
The All The Lovers star added that she "had to dig her heels in" to overcome personal and public doubt about her ability.
She said: "I’ve got a damn strong constitution. I’m like a little terrier, I will do it."
Minogue revealed her surprise this week at how she had decided to start touring so soon after her cancer treatment.
