LEWISTON — Whether they walked, ran or cycled, hitting the pavement to fulfill pledge commitments was what motivated 3,871 participants in this weekend’s successful 6th annual Dempsey Challenge.

The tally announced at closing ceremonies Sunday afternoon was “1.1 million and counting,” according to Aimee Arsenault, manager of special events and development at the Patrick Dempsey Center for Cancer Hope & Healing. That would put the six-year total raised for the center more than $6 million, with 100 percent of all donations going to the center.

“This has been the best event yet,” Arsenault said.

Patrick Dempsey, the Turner native and well-known actor on ABC-TV’s “Grey’s Anatomy” who founded the event, led hundreds of cyclists Sunday morning as they crossed the starting line at Simard-Payne Memorial Park.

Sunday’s focus for bicyclists was on courses of 10, 25, 50, 70 and 100 miles on roads in Lewiston, Auburn, Poland — and for the longer rides, into Casco, Naples, Oxford, Bridgton and Harrison. Hundreds of people at many “cheer stations” along the way supplied boisterous support.

“This is a unique community,” Dempsey said in his closing remarks. “You hear that from people around the world.”

Dempsey and his sisters, Mary Dempsey, who is assistant director of the center, and Alicia Dempsey, reminded the audience that this year’s Dempsey Challenge was particularly difficult for them because their mother, Amanda Dempsey, a multiple-cancer survivor for whom the center was founded, died six months ago.

With emotion creeping into his voice, Dempsey said, “Every street has memories for me.”

Rolf Hoffmann, senior vice president of Amgen’s U.S. commercial operations, cycled the event’s 50-mile course.

“I am stunned and in awe of what a community like this can do,” he told the crowd. “If there were more communities like this in America, it would be a much better place.”

Amgen, a major California-based pharmaceutical company that makes medicines for serious illnesses such as cancer, has been the Dempsey Challenge’s lead sponsor every year.

Peter Chalk, CEO of Central Maine Healthcare, paid tribute to the event sponsors and the 800-plus volunteers at the event.

U.S. Sen. Susan Collins, R-Maine, also addressed the crowd. She said that two of her brothers completed the afternoon’s 70-mile runs, and her sister-in-law rode the 50-mile course.

Dempsey’s appearances on the starting-line stage Saturday and Sunday mornings were tremendous crowd-pleasers. He signed autographs and posed for photos.

Before Sunday morning’s cycling event began, Dempsey made a special presentation. He gave a new bicycle to 83-year-old Don Robitaille of Lewiston, who has been an avid cyclist for 40 years. The high-tech bike was the gift of Dempsey and Specialized Bicycle, a major California bike manufacturer and Dempsey Challenge sponsor.

Robitaille took part in the 50-mile circuit and was greeted by volunteers Sunday afternoon as he rolled into the 44th mile at the Lewiston Junction Road rest stop near the Auburn-Lewiston Municipal Airport.

“Cheer stations” were set up at intervals along the ride routes. Some stations were very imaginative, such as a tiki bar or an arch of balloons over the highway.

There were rest stops on all of the courses. At the medical tent stationed at the Elm Street School in Mechanic Falls, personnel said no accidents or medical incidents had occurred. The worst injuries seemed to be a couple of skinned knees.

The Auburn rest stop near the airport included a communications station for relaying information, manned by Jason Jawenus. He said there were few unusual events, except for locating a 10-year-old who had missed a turn on the 10-mile course. The boy, who was not harmed, was picked up about 10 miles away from the route he should have followed, Jawenus said.

The bike service tent, operated by Rainbow Bicycle of Lewiston, performed some minor maintenance and repair work for arriving bicyclists. Manager Jared Buckingham said the most common request was to inflate the bikers’ tires. He also said he had seen a couple of crooked derailleurs, the essential gear-changing mechanism on multi-speed bikes.

Buckingham said he’s amazed when some riders come to him for service on bikes that appear to have been taken “off the wall” only once a year for this event.

“Some of them even have cobwebs,” he said.

Medical personnel were pleased with this year’s summery weather. Steve Doczy-Bordi, a team leader at the medical tent of Maine Task Force 1, Northern New England Metropolitan Medical Response System of the U.S. Department of Homeland Security, said the hot weather had not brought on any dehydration problems, because the humidity has not been extreme. He said last year’s cold, damp conditions had led to some hypothermia issues. One man, whose temperature had dropped dangerously low during last year’s cycling event, required medical treatment, he said.

That man had dropped by the medical tent a few moments before to thank the team for their attention and care the previous year, he said.