Minogue was performing in Manchester, north-west England, when she stopped and cancelled the rest of the show because of flu.
She was diagnosed with cancer in May 2005 and had to suspend the Showgirl tour in Australia but resumed performances in her homeland in November 2006.
The 38-year-old had surgery for breast cancer in Melbourne in May 2005, followed by a course of chemotherapy in France, where her boyfriend, actor Olivier Martinez, has a home.
"Kylie is suffering flu, as are other members of the tour group, including her manager. It is not linked to her breast cancer," a spokesman for the star said.
Minogue had launched the British leg of her tour with a New Year's Eve show in London characterised by a series of costume changes and lavish, sequinned and feathered outfits.
Her hits include "I Should Be So Lucky" and "Can't Get You Out Of My Head".