Miguel Almaguer's mother was diagnosed with stage 3 lung cancer in 2013

When Miguel Almaguer first found out about his mother Clementina’s cancer diagnosis, he was more than just upset.

The NBC reporter was not only “angry” and “sad” at the situation, he explained in a Today article Thursday, but “confused.”

“My mom, Clementina, is literally the healthiest person I know. Her diet is incredible. She eats veggies because she likes them. She doesn’t drink. She exercises every day and wrestles with my nephews until they give up,” he said about his mom, who was diagnosed with stage 2 lung cancer in 2013 at age 65.

What’s more, he added, “she has never smoked.”

Miguel Almaguer and his mother Clementina
Credit: Miguel Almaguer/Courtesy NBC's TODAY

Lung cancer is the leading cause of cancer deaths in America, and will likely kill 135,720 people this year. More people die from lung cancer than all colon, breast, and prostate cancer deaths combined. The American Cancer Society estimates there will be 228,820 Americans diagnosed with lung cancer this year, 85 percent of whom smoked cigarettes.

Almaguer, 42, explained that doctors think his mother’s cancer is the result of a gene mutation. According to the American Cancer Society, as many as 20 percent of people who die from lung cancer in America have never smoked or used any form of tobacco.

Clementina underwent surgery, which doctors thought would get rid of the cancer. But they soon learned it had already spread to her lymph node—and possibly the rest of her body. The next step was chemotherapy and radiation.

Miguel Almaguer and his mother Clementina

When lung cancer is diagnosed at an early stage, 70 percent of people live at least five years. But once lung cancer spreads to other parts of the body, long-term survival is as low as five percent.

Clementina’s treatment took its toll.

“I felt like she was slipping away, and there was nothing worse than that. She was so weak, so skinny,” Almaguer said. “The woman who always exercised could barely walk.”

After she finished her treatment, Clementina had to undergo regular scans to see if the cancer had returned — a process that Almaguer described as “awful and terrifying.”

But, he says, “she beat the odds” and is currently in remission. She continues to get routine check-ups, while Almaguer is “loving every minute” with his mother.