Cassandra Callender, now 18, of Windsor Locks, Connecticut, drew national attention when she initially rejected chemotherapy treatments after being diagnosed with cancer in mid-2014.
In January 2015, the state Supreme Court ruled that Callender, who was known as "Cassandra C." during her legal battle to resist the chemotherapy treatments, was not mature enough at 17 to make her own decisions regarding her health care. The court ruled that Connecticut's Department of Children and Families could require her to undergo the chemotherapy.
The Supreme court upheld a lower court ruling that supported a decision by the state to take her into custody so she would receive treatment for what doctors called an aggressive but treatable cancer, according to court records.
Starting in December 2014, Callender was forced to spend five months at the Connecticut Children's Medical Center in Hartford under the temporary DCF custody until she completed her court-ordered chemotherapy.
Stephen Dunn / The Hartford Courant / AP
She was released from the hospital on April 27, 2015, in remission.
But on Saturday, she posted an update about her cancer on her Facebook page, with the image of a CT scan of her lungs.
"Well here it is," she wrote. "Here is my '85% chance' of life after chemo. Unfortunately I didn't make the 85%, I fell into the 15%. This is my catscan (sic) of my lungs from yesterday. This is the mass that is now inside of my lung.
"I've known about this for a while but it's been hard going public with it. But this is why I fought so hard against chemotherapy. I am so sick of being treated like number and how everything is based off of statistics. I am a patient not a number."
When she first learned she had been diagnosed with cancer, she told PEOPLE she wanted to explore alternative treatments first, before resorting to chemotherapy, which she viewed as "poison."
But the state argued that chemotherapy would give her an 85 percent chance of survival.
Now that she is legally of age to make her own medical decisions, she told the Associated Press in a text message Monday that she is "moving forward with alternative treatments."
Courtesy of Cassandra C.
When she was released from the hospital in April, she told PEOPLE she was thrilled to see her beloved cat, Simba, and of course, her mother, with whom she is very close.
She had not seen or spoken to her mother from New Year's Day in 2015 until Easter that year after DCF prohibited the teen from having any contact with her, she told PEOPLE.
On Monday, DCF released a statement saying, "The Department fully empathizes with and wishes the best for Cassandra and her family. From the beginning, the Department has been guided by the medical experts' judgment about what would be in Cassandra's best interest. Cassandra's health and well-being remain in the forefront of our thoughts and our hopes for her full recovery."
A GoFundMe account has been set up to help defray Callender's medical costs.