In it, Dern portrays Bobbi Lambrecht, author Cheryl Strayed's mother, who died of lung cancer just weeks after being diagnosed. Strayed told her story in her 2012 memoir -- and that story was turned into the 2014 film of the same name.
"I read Cheryl Strayed's memoir, 'Wild,' which is about her 1,100-mile hike solo across the Pacific Crest Trail, but on a deeper level it's the story -- the love story -- about she and her mother, who she lost when her mother was 44 years old to lung cancer," Dern told CBS News. "And so to play not only a woman who got that diagnosis and had walked through great trauma from a situation home-life with domestic violence...and severe poverty and raising kids on her own when she fled that marriage. But she had such a level of earned gratitude for each day. And the pearls of wisdom that she offered so profound her daughter, which she wrote so beautifully about, so profoundly impacted all of us who read the book. So to be part of the film and to share that story meant the world to me. And to be so deeply aware for the first time of how lung cancer impacts women in this country."
Dern wasn't a stranger to lung cancer prior to the film as her grandfather died of the disease when she was 6 years old.
"It was very unspoken, it was very hush-hush -- something almost to be ashamed of -- not because he was a smoker, because they weren't necessarily even correlating his smoking with his disease. But merely to be stoic and not be sick with something -- that was prideful. And suddenly one day he was gone and I never understood it," she said.
Dern says after being involved with "Wild" and getting to know Strayed she became inspired to do more.
Now she's advocate for the cause, teaming with American Lung Association's Lung Force, in partnership with CVS Health, to help unite women and men everywhere to share their voice and make lung cancer a public health priority. It turns out that lung cancer is the No. 1 cancer killer of women, killing almost twice as many women as any other cancer, according to the American Lung Association.
Dern was among the advocates taking part in a panel on May 12 during Women's Lung Health Week -- from May 10 - May 16.
"The hope is that we will raise awareness and we will get people go to on LungForce.org to learn more," she said.
We caught up with her at the event in New York, where she spoke about "Wild" and more. Check out our sit-down interview above.