Olivia Newton John, singer and actress perhaps best known for her starring role opposite John Travolta in kitchy classic “Grease”, has announced that she is postponing several upcoming tour dates after being diagnosed with breast cancer.

Her tour had been postponed already due to back pain, but the singer announced in a Facebook post Tuesday that that pain had been caused by cancer which had metastasized to her sacrum. She plans to complete a short course of photon radiation therapy and utilize natural wellness therapies, and says she is confident she will return to her touring schedule later this year.

This is not the first such diagnosis for Newton-John, 68, who was first diagnosed with breast cancer in 1992 and has become a prominent advocate for cancer patients after first rising to fame in the 1970s.

According to a story in USA Today, publicist Michael Caprio says ticket buyers for the upcoming concerts can contact venues directly about refunds, and rescheduled dates will be posted at her website – OliviaNewton-John.com – when they are scheduled.

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