Shannen Doherty's doctor called the late "Charmed" actress, who died Saturday after a long battle with cancer, an "incredible warrior."

Oncologist Dr. Lawrence D. Piro told People in an interview published Tuesday that while the 53-year-old actress "wasn't ready to leave because she loved life," her cancer battle "turned much more difficult in the last couple of weeks."

Piro added that the "Beverly Hills, 90210" alum, who was diagnosed with breast cancer in 2015, was "a very intelligent person" who "was a very active participant in her entire health journey."

"In her mind, she was not wanting to consider any other alternative than 'we were beating this and we were engaged in life,'" Piro said. "We didn't really talk about what that meant in terms of additional time for her because that just wasn't how she operated. She wanted to live every day, not as if it were her last day, but as if it were the beginning of a whole another chapter for her."

But as her health took a turn, Piro said in their last conversation Doherty was "in the process of realizing" it.

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"The conversation was about love and support and caring and still fighting through," he said. "She wanted to continue to take treatment and fight through, even though her physical condition had taken a bit of a downturn. And so we did."

Shannen Doherty,'Beverly Hills, 90210' star, dies at 53 after cancer battle

Despite Doherty's "limited situation of options," continuing to fight "wasn't even open for discussion," Piro said. "That's not how Shannen lived. She was an incredible warrior in everything she did."

Her final moments were filled with care and love, he said.

"In the last few hours, she was in a place where she was very comfortable and sleeping and transitioning, and she was surrounded by some of her very close friends," Piro told the outlet. "The room was surrounded by a select group of friends that were giving her a lot of care and support. It was somber and sad, but beautiful and loving. The hardest thing about this was that she wasn't ready to leave because she loved life."

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Doherty sang Piro's praises in 2016, saying in an Instagram post she and the president and CEO of The Angeles Clinic and Research Institute in Los Angeles had "a great relationship, one of mutual respect." Doherty said at the time it was important to find a "dream team" that listened to your concerns and to not "settle."

That dream team also included oncologist Dr. Amin Mirhadi. She had both doctors on her "Let's Be Clear" podcast this year.

Doherty has been open about her health. In 2016, she told USA TODAY that the cancer had spread to her lymph nodes. For a brief period, it appeared Doherty was in the clear. After a single mastectomy that same year, she completed radiation and chemotherapy treatment in February 2017 and announced she was in remission two months later.

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Then in February 2020, Doherty revealed that her breast cancer had metastasized to Stage 4. In June 2023, she announced on Instagram that a CT scan months prior showed the cancer had spread to her brain, for which she was receiving radiation.

In November, she shared in a People cover story that the cancer had spread to her bones.

Doherty's death was confirmed Sunday by publicist Leslie Sloane in a statement shared with USA TODAY after People broke the news of the star's death. On Saturday, the actress "lost her battle with cancer after many years of fighting the disease," Sloane confirmed.

Doherty died "surrounded by her loved ones as well as her dog, Bowie," Sloane wrote in a statement.

The actress starred as Prue Halliwell, one of the sisters with magical powers on TV's "Charmed," and had roles on TV's "Little House on the Prairie," as well as in the movie comedies "Mallrats" and "Heathers."

She got her big break on Fox's teen soap "Beverly Hills, 90210," portraying high schooler Brenda Walsh.

Contributing: Brendan Morrow and Erin Jensen