Kylie is suffering from breast cancer, and she's cancelled her upcoming 20 dates in Austrailia, from 19th May until 14th June as well as her headline slot at Glastonbury Festival on Sunday 26th June.
Her tour company said ""She will undergo immediate treatment and consequently her Australian tour will not be able to proceed as planned."
Kylie said today: "I was so looking forward to bringing the Showgirl tour to Australia and to Glastonbury, and am sorry to have to disappoint my fans. Nevertheless, hopefully all will work out fine and I'll be back with you all again soon".
A decision will be made by the Festival on what's happening with a replacement act for her slot just as soon as they've had time to think about what to do.
Glastonbury Festival made an earlier statement at around 11:15 today, which reads as follows:
Glastonbury Festival was saddened to hear the news that Kylie Minogue has been diagnosed with breast cancer. The singer’s Australian tour has been cancelled, and it is still unclear whether she will be able to undertake her headlining slot at the Festival at the end of June. As soon as we have any more definite news we will pass it on. Meanwhile our thoughts are with Kylie at this very difficult time.
eFestivals wishes Kylie a swift recovery, and looks forward to seeing her back in action soon.
eFestivals is 
