Speaking to X magazine, the singer revealed that 'No More Rain' and 'Stars' on her previous album X were about her experience fighting the disease.
Minogue said: "There were other songs that were way more personal, and I did sing those on tour. They were called 'Ruffle My Feathers' and 'Flower'."
Asked why these songs did not feature on her latest release, she explained: "You know, hindsight can be a terrible thing. I look back now and I wish I had pushed for those songs to make it on.
"The songs are chosen between myself and my record company - and it was terrifying for all of us. So whether they weren't good enough or whether they were too close to the bone...
"I still don't know why they weren't on there. Perhaps it was something my record company weren't comfortable with. But I know that I wrote them."
Minogue added: "For me it was really cathartic to get in the studio and at least write about that stuff. I got back into that album literally as soon as I wasn't on a schedule for treatment.
"But I hadn't processed how to publicly express myself at that time. My fans know I've expressed myself that way."
