WELLESLEY — For medical oncologist Dr. Toni Choueiri, philanthropy is one of the most powerful ways to continue the fight against cancer.

Choueiri said he was able to see that power firsthand earlier this year, when one of his patients survived kidney cancer because of a drug from a clinical trial.

“That saved his life,” said Choueiri, 43, of Westwood.

So when that patient’s son reached out to Choueiri about participating in this year’s Pan-Mass Challenge, he decided to go for it. Now, Choueiri is one of more than 6,300 cyclists aiming to reach a record-breaking goal of $52 million for the Dana-Farber Cancer Institute, “100 percent of which directly benefits patient care and cancer research at the hospital,” organizers said in a statement.


“To cure cancer, you need to do research,” Choueiri said near the start line at Babson College Saturday morning. “How we do that to a large extent is through philanthropy . . . and the PMC is really crucial in funding research.”

The two-day challenge kicked off early Saturday morning. The event began in Sturbridge, where the first group of riders crossed the starting line at 5:30 a.m. A second group left Wellesley around 7 a.m.

The ride went on as planned Saturday despite rainy weather, event organizers said.

Like Choueiri, Boston Marathon bombing survivor Patrick Downes will be participating in the PMC for the first time.

Downes, who lost his left leg during the attack, will be riding Sunday alongside rising Boston College junior and PMC veteran Jack Manning. Manning lost part of his leg during a battle with cancer and was treated at Dana-Farber.

The two met when Downes and his wife, Jessica, awarded Manning with the first Boston College Strong Scholarship last fall.

“From the time that we met around the BC Strong Scholarship, we realized how much we had in common, [despite] how different our roads to amputation were,” Downes, a BC alum, said.


Jessica also lost her left leg during the bombing. Her right leg was severely wounded and later amputated.

During his 80-mile ride from Bourne to Provincetown on Sunday, Downes will be riding with Team Jack, which includes Manning’s father and uncle.

“To contribute and participate in some way with something that’s so meaningful to them just felt like an opportunity too good to pass up,” Downes said.

Riders are able to choose between one-day rides and two-day rides that continue into Sunday. They pledged to raise donations between $600 and $8,000 depending on the route they chose. The longest ride stretches 192 miles from Sturbridge to Provincetown. Riders range in age from 13 to 85.

More than 2,600 riders lined up under a sunny sky at Babson College in Wellesley on Saturday morning before setting off.

Choueiri was riding the 85-mile route from Wellesley to Bourne.

After working at Dana-Farber as a physician for 11 years, Choueiri said, he was especially excited to participate in the PMC and meet some of the other riders.

“You feel that this experience is going to change you and everyone,” he said. “This is my first time, but there are people I’ve met who have been anywhere between the second to the 25th time and they mention one thing — [a] life-altering event. So I’m ready for my life to be altered today.”


Billy Starr, PMC’s executive director, started the event in 1980 after his mother battled melanoma. The PMC is now Dana-Farber’s single largest donor, according to the statement.

During the opening ceremonies in Wellesley, Starr’s wife Meredith Beaton-Starr took a moment to recognize the 900 cyclists this year who are cancer survivors.

As riders and supporters cheered and rang cow bells, she asked, “Will all the cancer survivors please raise your hands? Please take a moment to join hands with the person next to you and pause to remember why you ride, fund-raise, volunteer, and participate in the PMC.”

For Choueiri, one of the most meaningful parts of the PMC is the message it sends to Dana-Farber patients because “it tells them that they’re not alone.”

“This is not just a fund-raiser,” he said. “This is a celebration, a celebration of life for people who made it, but also a celebration of memory because some people lose their battle to cancer and hopefully each year there’ll be less and less people losing their battle to cancer.”

Sophia Eppolito can be reached at sophia.eppolito@globe.com. Follow her on Twitter @SophiaEppolito.