Justice Ruth Bader Ginsburg announces she's cancer free and 'that's good'

Ginsburg said she'll serve "as long as I'm healthy and mentally agile."

Less than one week before the Supreme Court is set to resume arguments, Justice Ruth Bader Ginsburg has announced that she is once again cancer free.

"I'm cancer-free. That's good," the 86-year-old told CNN in an interview late Tuesday. She was reported as "sounding energized and speaking animatedly."

Ginsburg, the high court's oldest member and celebrated feminist icon, underwent a three-week course of radiation treatment last August for a malignant tumor on her pancreas. The Supreme Court said in a statement at the time that the “tumor was treated definitively and there is no evidence of disease elsewhere in the body,” and that no further treatment was necessary.

She confirmed Tuesday for the first time that the treatment was successful, marking her fourth time battling and beating cancer.

Her first came in 1999 with colon cancer. Then, in 2009, she had surgery for early-stage pancreatic cancer. In late 2018 -- after Ginsburg fell and fractured three ribs -- doctors discovered cancerous nodules in her lungs. She subsequently underwent surgery to have part of her left lung removed and missed her first day of court in her 26 years on the bench.

Last November, following treatment for the cancerous tumor on her pancreas, Ginsburg missed another day of oral arguments for what the court described as a stomach bug. She was briefly hospitalized later in the month for "chills and a fever."

Throughout her health battles, Ginsburg has remained an active and full participant in the business of the court, relying on the briefs and argument transcripts when she has had to miss a session.

Her illnesses have raised concerns among Democrats who worry another retirement or vacancy on the court while President Donald Trump is still in office means another conservative-leaning judge will likely be confirmed to the lifetime appointment.

One of four liberal-leaning justices on the nine-member court, Ginsburg has said she will continue to serve "as long as I'm healthy and mentally agile."

"I think my work is what saved me because instead of dwelling on my physical discomforts, if I have an opinion to write or a brief to read, I know I've just got to get it done so I have to get over it," she told NPR in July 2019.

The court is scheduled to reconvene Friday for its first private conference of the new year.

ABC News' Devin Dwyer contributed to this report.