The Grease star announced in 2017 that she had been diagnosed with metastatic breast cancer that has spread to her back

Despite her diagnosis with stage 4 breast cancer, those close to Olivia Newton-John are hitting back at reports that the singer’s health has taken a turn for the worse.

A representative for the iconic entertainer and Grease star, 70, who announced in 2017 she’d been diagnosed with metastatic breast cancer that has spread to her back, told PEOPLE on Wednesday that the recent reports claiming her body is “shutting down” and that she has only “weeks” to live are “ridiculous” and “crap.”

Newton-John’s niece, Tottie Goldsmith, also spoke out on Instagram on Wednesday to clear up the mounting rumors about her aunt’s health.

“Just giving you the heads up that Livvy is in good health, so let’s leave that distressing rumor where it belongs,” Goldsmith shared, along with a photo of her posing with Newton-John.

Goldsmith told Australia’s Seven Network that Newton-John had given her permission to speak out about her publicly, and that “you can rest assured she is going nowhere and in really good health. A sick rumor.”

Last week, RadarOnline claimed that Newton-John’s “bodily functions appear to be shutting down” and that she is “clinging to life” so that she can see her daughter, Chloe Lattanzi, marry her longtime fiancé James Driskill in 2019. It also said Newton-John is spending her “final days” at her home in Santa Barbara with her husband of 10 years, John Easterling.

The report triggered a whirl of rumors on social media and in tabloid reports in Newton-John’s native Australia, including one which claims she has only “weeks” to live.

Newton-John was first diagnosed with cancer in 1992 and underwent a partial mastectomy, nine months of chemotherapy and a breast reconstruction. After beating the disease, Newton-John became an advocate for breast cancer research and early detection.

F:PHOTOReady RoomActionsInsert Request47705#gettyGettyImages-137906596.jpeg
Olivia Newton-John
| Credit: Nic Gibson/Newspix/Getty

In May 2017, doctors diagnosed Newton-John with stage 4 breast cancer that had metastasized to the sacrum. The star initially postponed the first half of her concert tour because of severe back pain from what she thought was sciatica, but further tests discovered it was actually cancer that spread.

Newton-John’s most recent diagnosis is her third bout with cancer, as she revealed in September that she had faced a return of the disease in private back in 2013.

During a lengthy sit-down on the Australian television program Sunday Night, Newton-John said she first discovered a lump on her right shoulder following a minor traffic accident in 2013. Though she initially believed it to be bruising sustained in the accident, further tests confirmed that it was a return of the cancer.

In addition to traditional medical treatments such as chemotherapy, Newton-John credits beating cancer the first time to her overall wellness plan. The cancer treatment center in Melbourne, Australia, which bears her name now offers patients holistic treatments including yoga, massages, art and music therapy to aid in their recovery.

The actress also shared during an appearance on Today in 2017 that she has been treating the pain with medical marijuana that her husband grows.

“People have this vision from the ’60s of people just sitting around and getting stoned,” she said. “It’s not about that. This plant is a healing plant. I think we need to change the vision of what it is because it helped me greatly and it helps with pain and inflammation.”

In August, a tabloid report alleged that Newton-John canceled a handful of speaking engagements due to the progression of the illness — a claim that she herself denied.

“Olivia Newton-John’s two upcoming speaking appearances in Australia were canceled due to scheduling conflicts with her upcoming promotional tour for her new book, Don’t Stop Believin’ and the ONJ Cancer Wellness & Research Centre’s Wellness Walk & Research Run,” read a statement posted on her social platforms. “Not illness as falsely reported.”

In September, a source told PEOPLE that Newton-John had been feeling healthy.

“She’s feeling and looking great and was just dancing with John Travolta at a Grease 40th anniversary event,” the source said. “Everything that’s being reported about her diagnosis is the same news she released last year.”