Olivia Newton-John diagnosed with breast cancer

AP

LAS VEGAS --

Iconic performer Olivia Newton-John is once again battling breast cancer.

The singer and actress announced on her Facebook page Tuesday that what she originally believed to be back pain was actually breast cancer that had metastasized to her lower back.

Newton-John will undergo photon radiation therapy and expects to resume her tour later this year.

"I decided on my direction of therapies after consultation with my doctors and natural therapists and the medical team at my Olivia Newton-John Cancer Wellness and Research Centre in Melbourne, Australia," Newton-John said in a news release.

Newton-John's upcoming performances -- including one on June 8 at the Stafford Center -- have been postponed. Ticket holders should contact the venue directly for refund information.