From one cancer survivor to, hopefully, another.

Tomorrow, Kailua resident Paul Sibley will start a 160-mile run around O'ahu, with the final 26.2-mile leg being Sunday's Honolulu Marathon. The nonstop, round-the-clock run is to raise cancer awareness and funds for a young boy diagnosed with cancer.

To those who do and don't know Sibley, they think he's crazy. But he's a longtime runner who has completed Ironmans and ultra marathons that doubles and triples the distance of Sunday's race.

At the core of it all is a life-changing experience he can relate to all too well, one that transcends age and geographic distance. Sibley, a 37-year-old cancer survivor, is doing the Trevor 160 Challenge for 6-year-old Trevor Sims, a Louisiana boy who was diagnosed with rhabdomyosarcoma last year.

"Why not do something that's pretty long and epic and people will pay attention to?" said Sibley, a manager at HMSA. "It's a way to connect the perimeter of O'ahu with the marathon route, and make it to the whole island. In a way, I wanted to circle the whole island of communities. People from the North Shore, Wai'anae, every part came out to help me (during cancer treatments). In a way, it's giving back."

Trevor is a classmate of Sibley's nephew in Baton Rouge. Sibley was talking with sister Wanda Gawarecki and told her about his idea of running around the entire island as part of the marathon.

She thought he was crazy, but her ultramarathon-running brother has been doing those long distances for years. Sibley's longest run was 70-plus nonstop hours in California.

"He said he wanted to do it to raise awareness for cancer and I told him about Trevor," said Gawarecki, who has run a few marathons and half-marathons. "It was about the same time we found out about everything and he said, 'Let's do it for Trevor.' "

According to the National Cancer Institute, childhood rhabdomyosarcoma is a soft tissue malignant tumor of skeletal muscle origin and makes up 3.5 percent of cancer cases in young children. Trevor has undergone a year's worth of chemotherapy since the affected area is in his sinus cavities, which are inoperable. He has six months of treatment left. He's being homeschooled and misses his friends.

"He has good days and bad days," Gawarecki said. "Beginning at St. Jude (Children's Research Hospital in Tennessee) the first three to four months, that was tough being away from everybody up there and poked with needles. He's been a trooper, but it's hard hitting."

Sibley can relate to what Trevor is going through — the pain, the treatments, the listless days, the dramatic health and appearance changes. In January 2006, a small mole was excised from underneath Sibley's chin. It was excised again when it returned, and only then was it discovered that it was much more invasive — through the lower half of his face — than anyone had thought. He considers the diagnosis of squamous cell carcinoma as a "lucky diagnosis."

When six rounds of removing the tumor wasn't enough, his physician team decided he was ready — given his health and fitness level — for radiation treatment. The daily treatments started in February 2006, and for a while, Sibley continued to run, work and live life with some sense of normalcy.

In the coming weeks, it all changed. Eating and swallowing became painful from sores. At times he couldn't breathe, speak or get out of bed. He lost 30 pounds and muscle mass.

"It took everything," Sibley said of the treatments. "Sometimes, it doesn't affect people at all and for some people, it knocks them down. The same thing for chemotherapy. Some can do chemotherapy, some can't get out of bed."

His radiation treatments ended in April 2006 and within six months, Sibley did a 100-mile run. He wanted to prove a point, to show his resiliency. He said the decision wasn't smart, but he "did it as a statement."

"I wanted to be back where I left, show everyone I could keep going," Sibley said. "It was more of a motivation and pay back to everyone that helped me, family and friends, to show Paul is fine, don't worry, let's move on ... because a lot of people were really scared.

"I wasn't ready, everyone knew it, a lot of people didn't think I would make it."

It wasn't until 2007 that Sibley felt he was finally building up, and by the middle of that year, "I knew I was coming back pretty strong."

Tomorrow, Sibley will start Trevor 160 at Aloha Tower and estimates it will take 40 hours to get to Ala Moana, the starting point for Sunday's race. By then, it'll be somewhere between 1 a.m. and 2 a.m., giving him a few hours to rest up for the 5 a.m. marathon start.

It'll be a solo journey for the most part, with friends and fellow runners meeting him throughout the course. He'll also bring a toy, similar to the gnome in those travel commercials, and take pictures of it at various spots throughout the weekend.

He plans to mail it to Trevor for Christmas. The dream is that Trevor will be a survivor, too, and when he encounters a challenge later in life, he can think about putting "one foot in front of the other."