By Stephanie Stahl

PHILADELPHIA (CBS) — With Philadelphia’s Broad Street Run fast approaching, 40,000 people have signed up, making it a sold-out race.

Just days before Sunday’s race, a group of dedicated runners warmed up on Philly’s Belmont Plateau.

They are Team CMMD, named after its founder Dr. Christine Meyer MD.

“Our running team is huge. We have almost 2,000 people now, from our little team of three or four that started back then,” says Dr. Meyer.

It was 2013 when Dr. Meyer realized she needed to do something after treating so many young cancer patients.

One of her patients was Karen Baker.

“She was amazing,” said Karen’s husband James as he struggled to talk about his wife.

Karen died six months ago from cancer at the age of 42.

“She was a very important part of this team,” he said. “She was so strong.”

And now James is finding strength with the team.

He’ll be out there with them on Sunday.

“It’s going to be a tough day, but I have Team CMMD with me and we’ll have lots of people cheering for us, so we’ll make it through just one day at a time,” he said.

Team CMMD has raised and donated over a million dollars to the American Cancer Society over five years.

“It makes me realize that even when you think you’re not making a difference, you are,” said Dr. Meyer.

Money raised from the Broad Street Run helps cancer patients like Amy Lukasevich.

She is a team member who was diagnosed with lymphoma.

“It’s incredible. You constantly have an army behind you,” said Lukasevich. “It’s just so appreciated.”

There’s camaraderie mixed in with plenty of running and training for the 10 mile race.

“Some of us are going for a time, some of us are going for a purpose,” said Dr. Meyer.

Getting those high fives and those hugs, that’s what makes Broad Street so special.

With contributions from teams like CMMD, runners have been raising $750,000 a year benefiting the American Cancer Society.

Stephanie Stahl