Kylie Minogue, who turns 37 next week, has been diagnosed with breast cancer.

The pop star has postponed the Australian and Asian leg of her "Showgirl - The Greatest Hits" tour, as well as her appearance at Glastonbury at the end of June.

Kylie was enjoying a holiday in Melbourne with her family and her boyfriend of two years, French actor Olivier Martinez, 39, when she discovered she had early breast cancer.

She will undergo treatment immediately, heading to hospital as early as tomorrow. She is expected to stay in hospital for two days and to then return to her parents' home in Melbourne to recover.

Kylie has herself backed cancer charities strongly ever since her father was treated for prostate cancer.

"I was so looking forward to bringing the "Showgirl" tour to Australian audiences 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."

Sister Dannii Minogue said today: "The news is very upsetting. Although, as the cancer has been diagnosed at such an early stage, we are all very optimistic that everything will be OK.

"We're all very thankful for the endless messages of love and support Kylie has been receiving - I know all your kind thoughts will mean the world to her as she gets better."

Pop producer Pete Waterman, whose former record company Stock Aitken & Waterman launched Kylie's pop career in 1988: "I am so shocked to hear this news.

"My very best wishes go to her, and of course her family, at this difficult time."

Pete, who lost his eldest son Paul, 33, to a mystery illness in January, added: "My heart goes out to her."

Ex-boyfriend and fellow "Neighbours" star Jason Donovan said: "I was shocked and concerned to hear of Kylie's illness.

"My thoughts are with her and her family at this difficult time. I sincerely wish her well with this treatment. Kylie's a strong woman who will fight this battle on every front."

Kylie's management today released the following statement: "Whilst at home in Melbourne with her family this week prior to her Australian Showgirl tour, Kylie was diagnosed with early breast cancer.

"She will undergo immediate treatment and, consequently, her Australian tour will not be able to proceed as planned."

The tour was due to kick off in Sydney on Thursday. Kylie had 21 dates planned in Australia, six in Melbourne alone. She was also due to headline the Glastonbury Festival at the end of June.