She is undergoing chemotherapy treatment and has had to give up her job at Wanganui Hospital's dental unit.
Ms Luoni is a colleague of Ms McCormick's mother, and when she and her two friends found out about Ms McCormick's plight they decided to do something to help her.
Ms Benton said they wanted to help because cancer could strike anyone at any time.
"That could easily have been me facing cancer, or anyone else I know."
She said she also wanted Ms McCormick to know she was not alone in her struggle.
"I hope Jess is able to draw strength from the fact that the community cares about her," she said.
None of the three women are runners but they are training hard for their challenge, running four times a week together.
Ms van de Vyver said she had never been keen on running but she was prepared to do it for a good cause.
"We're not aiming to win it, we just want to finish it in a good time," she said.
Ms Luoni said the team hoped to raise about $2000 to give to Ms McCormick.
"All the money we raise will go to Jess. We hope she'll use it to buy herself a wig, or for expenses related to her treatment, or to give herself a holiday after she's finished chemo," Ms Luoni said.
A fundraising page has been set up on Facebook, called 4Jess. Donations can be made through the site, or at any branch of the BNZ. The bank account number is 02-0792-0038866-001.
Ms McCormick was invited to be in a photo and be interviewed but she declined.
