LEWISTON, Maine -- Actor Patrick Dempsey traded his race car for a bicycle Saturday at the Dempsey Challenge in his home state.

Dempsey returned to Maine for the two-day, bike-and-run fundraiser that started after his racing team's victory at the "Six Hours of Fuji" endurance race in Japan.

The event in Maine, where Dempsey was born, is a fundraiser for The Patrick Dempsey Center for Cancer Hope & Healing, which he and his sisters created in 2008 in partnership with the Central Maine Medical Center in Lewiston. They were inspired by their mother, Amanda who died from cancer last year.

Dempsey told the Sun Journal that coming home for the Dempsey Challenge is like coming home for a family reunion, sharing memories, grief, accomplishments and support.

"The overall feeling and openness of everyone participating in the challenge is magical," he said.

On Sunday, he'll be participating in a 50-mile ride.

Dempsey is best known as Dr. Derek "McDreamy" Shepherd on TV's "Grey's Anatomy," but he left the show earlier this year and put his focus on his racing team, Dempsey Proton Racing. In addition to racing, he's filming the movie "Bridget Jones's Baby" in London.

About 4,000 people were participating in the challenge. The goal is to break the 2014 record of $1.41 million raised by 3,871 participants, said Aimee Arsenault Labbe, the Dempsey Center's manager of special events and development.