After a long battle with 3 different types of cancer, a footloose Orlando man takes on a 2,650-mile hike

But if you have to ask why he’s doing it, he wrote, you wouldn’t understand. 

It is not simply that he hopes to raise $26,500 for the dramatically underfunded battle against lung cancer, a disease expected to claim the lives of 160,000 Americans this year — more than colon, breast and prostate cancers combined.

Nor is it about creating some kind of legacy. Though followers can read his ongoing exploits on lungcancerhike.org, the website is intended to give fellow cancer survivors hope — and to collect donations for the American Lung Association — not to brag.

“John is the guy you want with you in a foxhole,” said Eric Gray, an executive director at the American Lung Association of Florida. “He’s the guy who makes you believe anything is possible.”

Casterline is a favorite at Orlando lung-cancer support-group meetings, and Gray often uses him as a beacon of hope when counseling the newly diagnosed.

“In years past, there hasn’t been a lot to say to people other than, ‘I’m so sorry,’ ” Gray said. But now I can say, ‘Let me tell you about this guy who had Stage 4 lung cancer and this remarkable thing he’s doing …”

Casterline was diagnosed in August 2006, a week after he retired from 21 years working for 7-Eleven preceded by 21 years in the Navy. He had quit smoking seven years earlier — 1999, the same year he took up backpacking at the urging of his eldest son. By the time the disease was detected, it was so far advanced he was given a 3.5 percent chance of surviving the next five years.

“You go through these stages of grief,” he said. “For two or three days, I figured I wouldn’t make it a year.”

It may have been the only time his relentless spirit waned, and even then it didn’t last long. He researched exhaustively, interviewed doctors at five hospitals — including Memorial Sloan-Kettering in his birth state of New York — and ultimately selected M.D. Anderson Cancer Center Orlando. He went through surgery, chemotherapy and more than one round of radiation, and by February 2007 he was officially cancer-free.

That lasted a blissful 3 1/2 years, until he developed prostate cancer. He had just finished surgery for that in November last year when, one month later, doctors discovered the earliest stage of throat cancer. 

“He exercised all through chemotherapy and radiation,” said Dr. Jennifer Tseng, his medical oncologist, who counts herself a fan. “Probably the only time he didn’t exercise is when he was in the hospital after surgery. And even then, he was back on his feet in no time. He’s got an amazing spirit and willpower.”

The average person undergoing radiation would still be trying to eat solid food at this point, she said. Casterline, who began competing in marathons 10 years ago, has been out hiking 14 miles a day wearing a 35-pound backpack. Within the past week, all three of his doctors have given their blessing to the upcoming hike.

In fact, in some ways, Casterline’s wife of 41 years, Sue, has been the toughest sell.

“When he first told me about this trip, I thought, ‘You’re out of your mind,’ ” she admits. “It was just surreal. But he’s a force of nature, and he’s going to do what he’s going to do. I mean, I can’t stop him.”

She did, however, make him update his will.

As she says this, the family room has turned into a staging area with 13 cardboard boxes of food due to be shipped to various post offices near the Pacific Crest Trail. Those are for the times when the nearest store is 20 miles away. Casterline has the spots numbered on spreadsheets that detail his mileage, route-elevation changes, meet-ups with his wife and two grown sons, and notations on the hazards du jour. 

“Water supply contaminated — dead rodents,” he notes for Day 5, a 20-mile stretch through the scrub oak and chaparral of Southern California. “Poison oak about mile 105.”

His gear has been weighed to the nearest tenth of an ounce. All his clothing comes in at 2.56 pounds. His tent, sleeping bag, backpack, ground cover and pad: 7.66 pounds. Total, with cooking and hygiene supplies, medications, emergency whistle, duct tape, bug repellent, iodine tablets, reading glasses and playing cards: 15.97. It’s the food and water that will add an additional 20 or so pounds. Plus there’s the 1-pound ice axe he can ditch after the halfway point.

He has coaxed sponsorships from Nestlé, which owns PowerBar energy products, and Mango International, which sells a small solar panel to recharge his iPhone. He’ll also carry a pocketknife and perhaps a 6-ounce Kindle reader. But he’s still on the fence over a distress signal that alerts rescue workers you need to be airlifted to a hospital.

“It’s 8 to 10 ounces,” he said, frowning. 

Though Casterline feigns fearlessness most of the time, he admits one enormous worry: failure.

“I’m very determined, mentally and physically, and I know I’ve already been tested pretty hard,” he said. “But that’s one of my greatest fears: that I won’t make it.”

On bad days — and there will be bad days — he will remember to look at the names his granddaughter has printed on his backpack in ink. “Alysan F.,” “Judy C.” and “William R.,” they read. There are 100 names in all: lung-cancer patients or their loved ones. Some he has only met online. If not for himself, then at least for them, he must try to persevere.

No one is betting against him.

“Short of getting eaten by a bear,” his wife said, “he’s going to do it.”