Originally Published: 11 MAY 23 08:59 ET

By Lisa Respers France, CNN

(CNN) -- A second opinion helped turn around actor Dolph Lundgren's battle with cancer.

In an interview on "In Depth With Graham Bensinger," Lundgren, 65, shared that he has quietly been fighting cancer since doctors found a tumor in his kidney in 2015.

The "Rocky" franchise star said he believed he had acid reflux in 2020, when in reality it turned out to be more tumors which were surgically removed.

"There's a picture there I was going to direct and star in that was starting in the fall. The doctor called me when I was in Alabama ready to shoot and said they found one more tumor in the liver," Lundgren said. "So I was like 'Oh okay.' At that point it started to hit me that this is kind of something serious."

He said the doctor informed him that the tumor had grown so large it was inoperable.

That meant a different kind of treatment which Lundgren's fiancée, Emma Krokdal, said left him with horrible side effects.

"His mouth got really sore," she recalled . "His hands got sore, [his] feet, and he couldn't eat anything warm, anything cold or anything spicy. So that was a struggle to get food down so he kept losing weight."

"The Expendables" star said he was given two to three years to live, though he said he sensed the doctor who told him that didn't believe Lundgren had that much time.

"I mean you kind of look at your life going 'Oh I've had a great life,'" he said. "I've had a freaking great life. I've lived like five lifetimes in one already with everything I've done."

"So It wasn't like I was bitter about it," he added. "It was just like, you know, feel sorry for my kids and my fiancée and people around you."

His daughter, actress Ida Lundgren, 27, got visibly emotional talking about her father.

"I had a deep conversation with my dad about what would happen if he, you know, passed away and stuff," she said. "That was a horrible conversation."

Fortunately, the elder Lundgren got a second opinion from oncologist Dr. Alexandra Drakaki, who did another biopsy. She found a mutation which made the cancer treatable by medication which has helped shrink the tumors by 90 percent.

"There are certain parts of his body that the cancer is responding really well," Drakaki said. "There's some lesions that we cannot see them anymore. So that is above expectations."

Lundgren got emotional talking about how he feels now.

"You know you appreciate life a lot more," he said. "You appreciate every day."