During visits home, Lilburn native Eric Shanteau maintains fitness and form in a lane at his old club, SwimAtlanta, stroking and kicking alongside youngsters half his age.

“They don’t know who I am,” said Shanteau, 27. “They look at me as just some old dude.”

Well, girls and boys, this old dude has quite the backstory. So dry yourselves off, gather ’round and meet your fellow Atlantan, who overcame a dreaded disease that struck at the most inopportune time, swam in the Olympics, befriended one of the world’s more renowned athletes over their common ordeals and will engage in his specialty, the 200-meter breaststroke, next week at the World Aquatics Championships in Shanghai.

Like all aspiring U.S. Olympic swimmers in early summer 2008, Shanteau was focused on the upcoming Trials. Discovering a lump in his testicle did not set off the internal alarm that it normally might have. His girlfriend, Jeri Moss, the voice of reason, urged him to get it checked.

An initial test indicated nothing untoward, but ultrasound revealed the harsh truth. The cancer was confirmed on the morning of June 18, just seven days before the Trials.

While weighing his options that afternoon, Shanteau did what swimmers do. He went to the pool and practiced.

There followed a stream of conversations with coaches, doctors and loved ones, none more poignant than with his father. Richard Shanteau was in an advanced stage of lung cancer, with a grim prognosis of recovery.

The year before, Richard had told his doctors, “Keep me alive long enough to let me see my son in the Olympics.”

Now he was telling his son, “Eric, either you have cancer or cancer has you.”

Even at full health and with a clear head, Shanteau would have been no certainty to qualify for the Games with a top-two finish. A speeding freight train needs time to brake, so he decided to ride the momentum and adrenaline from training through the Trials and worry later about the Olympics.

The best athletes apply blinders to their eyes and their brains, blocking off all distractions. Shanteau finished second in the 200. But it was less cause for celebration than a setup for disappointment if doctors did not clear him for Beijing.

They did, pending the results of weekly examinations that never changed their minds. His type of cancer yields at least a 95 percent survival rate (five years or beyond) with early detection, and deferring surgery until after the Games in late August was considered a minimal risk.

“If my life was ever in danger,” Shanteau said, “I would definitely have pulled out.”

The adults in Shanteau’s circle anticipated his stay-the-course call.

“Your whole life, you have a dream to do something like that,” said his SwimAtlanta coach, Chris Davis, who trusts that Shanteau would have withdrawn under more dire circumstances.

“I understood his decision,” said his mother, Janet Shanteau, who declined to say whether she initially agreed with it. “There was no doubt he would swim.”

Shanteau’s 10th place at the Games should be attached by an asterisk in the record books: * — He swam with tumor.

“From a swimming standpoint, it was definitely a disappointment,” he said, though the clocking was a personal best. “Taking everything into consideration, you really can’t ask for too much more.”

Olympic athletes tend to ponder retirement from elite levels at the end of each quadrennial cycle. Shanteau had reason to towel off for good. He had experienced the Games. He had a degree from Auburn. He was down to one testicle from surgery a week after returning from Beijing.

The retirement option stood little chance, though. It was up against Shanteau’s youth, the post-operative pronouncement that he was cancer-free and a newfound mission.

During recovery, Shanteau was contacted by Livestrong, the cancer-awareness foundation of incomparable cyclist Lance Armstrong. Shanteau was amenable when representatives invited him to become a Livestrong envoy, but could not resist asking a favor in return.

“I want to meet Lance,” he told them.

Three years later, the two are pals with a shared cause. Shanteau delivers speeches and visits hospitals on Livestrong’s behalf. His message to cancer victims, especially to youngsters whose suffering tears at his heart, boils down to this: “You can come back and be better than you were before.”

Those words would carry less meaning if Shanteau did not back them up with deeds. So he swims on, competitive as ever.

“He is swimming really, really well,” said Davis, who would wish Shanteau’s attitude and demeanor on anyone.

“I’ve never seen Eric come in [to the pool] in a bad mood. Never has he had a chip on his shoulder. You instantly like him.”

Shanteau trains regularly at USC, along with about three-dozen post-collegians and breaststroker nonpareil Kosuke Kitajima of Japan with an eye toward the 2012 Games in London. They set their own practice schedules, shortening workouts or playing hooky if the body asks, while relying on peer pressure to hold each other accountable.

To USC coach Dave Salo, emerging from the dark tunnel of cancer has made Shanteau a better swimmer.

“You tend to really appreciate the opportunity that you have,” Salo said. “I think he wakes up and says, ‘Thank God, I’m here.’”

His mother believes that Shanteau’s more balanced priorities are beneficial in the pool.

Swimming, Janet said, “is not the only thing in the world that’s important, like maybe it was at one time.”

For sure, Shanteau finds more enjoyment in the sport, less to freak out about. If nothing else, he surely is the calmest barefooted guy on the starting blocks.

“I will never be as nervous as I was when I was wheeled into surgery or when I was waiting on the test results,” he said.

Shanteau’s scales recently became more balanced than ever. In May, he married Moss, a fellow Auburn swim alum, though they did not date until after graduation. They reside in Marina del Ray, Calif., not far from his in-laws.

His own father is not around to see a possible Olympics sequel. Richard Shanteau died in August at 63. Their intertwined battles brought them closer, and Dad hung on not only to attend the Olympics, but to witness Shanteau set his first national record a year later.

Shanteau’s biannual tests for cancer have turned up negative. If the pattern holds, he will be considered in remission in 2013, subjected to a single yearly exam.

As a bonus, doctors say he is capable of siring children.

Coping with cancer, the old dude insists, has altered his life for the better. Straight ahead is a World Championships — and perhaps another Olympics, this time with a healthy body and a freed mind.