'One in a Million': Anne with an E 's Miranda McKeon on Getting Diagnosed with Breast Cancer at 19

Miranda McKeon was in the bathroom, adjusting her shirt, when she found the lump on her breast. She had been spending the weekend at a beach house with her friends after a year of pandemic college classes, excited for a relaxing summer, and "brushed across a lump that I hadn't felt before," the Anne with an E actress tells PEOPLE.

"I had the thought that, 'Wow, this is the moment.' I immediately went to the worst case scenario," she says. "This is the moment where everything changes and there's no going back. But after going down a little Google rabbit hole, my mind was at ease because I didn't think anything could be wrong because of my age."

The 19-year-old McKeon, though, did schedule a doctor's appointment right away, where they did an ultrasound and took a biopsy of the lump.

"I think they were more concerned than they let on because I really didn't think anything of it, to the point where I flew to San Francisco, where I was going to do a three-week work stay program on regenerative agriculture," she says. "I had just touched down in San Francisco and all my messages were coming through and I got the call that the biopsy came back positive."

That call, on June 14, was "surreal," says McKeon, who immediately got on a plane back to her family in New Jersey. She learned she was "one in a million" — an extremely rare case of a woman getting breast cancer as a teenager. The next day was the start of a litany of appointments — ultrasounds, mammograms, consultations with surgeons and oncologists — that have filled the last month.

Miranda McKeon Miranda McKeon

McKeon is trying not to focus on the stage of her breast cancer — it's considered stage 3, because it has spread to her lymph nodes — but her young age and overall health all point to a strong outcome.

"My doctor was like, 'Your stage doesn't define you. And your cancer is your cancer.' Which I appreciate because when you hear someone's stage, your mind goes straight to one place or another and I don't think that's necessarily representative of what I'm going through," she says. "Although I don't have the easiest case scenario, like I wish it hadn't spread to my lymph nodes or that it was a little less complicated, I never had a moment where I was like, 'Oh, am I going to die from this?' That was never really a thought. I think this entire time it's been more of like, 'Okay, we're going to treat this and solve it.' "

Her treatment plan is for four months of chemotherapy, with infusions every other week, followed by surgery and then radiation. But "we've realized that having breast cancer as a young woman involves a lot more factors than just treating the cancer itself," McKeon says.

One day after learning she had cancer, McKeon and her mom, Jill, were talking to a doctor about freezing her eggs.

"That was gutting," says Jill. "I said to the doctor, 'We'll talk about that later, this is already enough information.' She was like, 'Actually, we're talking about this because we have to.' "

And a week after getting her diagnosis, McKeon started injecting herself regularly to harvest her eggs "as a precautionary step," she says. "It's a safety net. I'll probably be able to have kids naturally on my own, and hopefully they'll just be donated to science in however many years, but we'll see."

Patty Connelly Miranda McKeon, with the marks from her egg retrieval injections

McKeon is now one week past her first chemotherapy infusion, on July 7, and is "managing as best as I can."

"I'm making it my job to find the beauty in all of this," she says. "I wouldn't have chosen this, I didn't choose this, I don't think anyone would choose this. But I'm making it my job to try and pull something out of this."

One thing that has made a huge difference for McKeon is sharing her story, through her blog and Instagram, where she has nearly 1 million followers.

"It's so cathartic for me," she says. "My blog is the one thing that is super tangible that has come out of this where I'm like, 'Damn, this is awesome.' I'm hoping that by documenting a good majority of this, that someone else will be able to read it down the line when they need it and they can find comfort and healing through it in the way that I do writing it."

"I'm writing these pieces and it kind of just comes out of me," she continues. "I feel more alone when I keep a piece to myself, so I've found so much strength through sharing it with this community."

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But to the young girls reading her story, McKeon wants them to understand that "this is super rare and not the norm," to get breast cancer at her age. But it's also quick, easy and important to do breast self-examinations and check for any odd lumps.

And McKeon is learning from this experience that she's stronger than she realized.

"I feel like as humans, we look at other people in other situations and think, wow, how are they doing that? Or wow, I could never do that. And I probably would have thought the same thing about myself, but here I am and I'm now living in this story and I think we can all handle a lot more than we think we can," she says.