Patrick Swayze, filming again less than a year after being given a grim diagnosis of pancreatic cancer, described chemotherapy as "hell on wheels" but said work had kept him feeling positive.

Swayze, 56, best known for his dance instructor role in the movie "Dirty Dancing," underwent months of chemotherapy and an experimental drug treatment to beat one of the most virulent forms of cancer, which experts say has only a 5 percent five-year survival rate.

"I do find myself, at the end of the day riding home, sort of catching myself with a smile on my face," Swayze told The New York Times in his first interview since returning to acting. "I'm proud of what I'm doing."

After a dramatic weight loss, Swayze has gained 20 pounds by drinking muscle-building shakes and is now working a 12-hour day as the lead actor in a new U.S. television police drama "The Beast."

"I'm still fine to work, I haven't changed - oh, I have changed, what am I saying? It's a battle zone I go through. Chemo, no matter how you cut it, is hell on wheels," he told the newspaper.