Shannen Doherty is opening up about a new development in her fight against cancer.

The Beverly Hills, 90210 alum, who revealed her stage 4 diagnosis three years ago, recently shared that her cancer has metastasized to her brain. Doherty gave the heartbreaking update to her cancer journey on Instagram this week.

"On January 5th, my ct scan showed Mets in my brain," the Charmed alum captioned one video, shared on June 6. "Yesterdays video was showing the process of getting fitted for the mask which you wear during radiation to your brain. January 12, the first round of radiation took place."

Doherty said her "fear is obvious," adding, "I am extremely claustrophobic and there was a lot going on in my life. I am fortunate as I have great doctors like Dr Amin Mirahdi and the amazing techs at [Cedars-Sinai Medical Center]. But that fear…. The turmoil….. the timing of it all…. This is what cancer can look like."

The 52-year-old's emotional post was met with love from friends like Sarah Michelle Gellar, who wrote, "You are a warrior."

Meanwhile, fellow pal Selma Blair wrote, "This is a lot. This is a lot to take on , still again."

The Cruel Intentions star, who has been vocal about her own health after her multiple sclerosis diagnosis, continued, "And I am wishing for all the wise peace you have learned to find you in the terror moments. To know we are holding you. Love. All love."

Doherty's health battle began nearly a decade ago when she was diagnosed with breast cancer in 2015. While the Heathers actress announced in 2017 that she was in remission, Shannen shared in 2020 that her cancer had returned the previous year and had been classified stage 4.

"It's a bitter pill to swallow in a lot of ways," she told ABC News at the time. "I definitely have days where I say, 'Why me?' And then I go, ‘Well why not me? Who else? Who else beside me deserves this?' None of us do. I would say that my first reaction is always concern about how am I going to tell my mom, my husband."

Shannen's health update comes amid another major life change, with her filing for divorce from husband Kurt Iswarienko after 11 years of marriage in April.

E! News previously reached out to Doherty and Iswarienko's reps for comment and hasn't heard back.

In the wake of the breakup news, Doherty shared a cryptic quote on her Instagram that read, "The only people who deserve to be in your life are the ones who treat you with love, kindness and total respect."

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