For an athlete, health is everything.

It takes full command of one’s body to run a marathon, make a diving catch of a line drive, or to gently flick a wrist for a drop-shot winner at the net.

When cancer wreaks havoc on the body, athletes are left wondering not only will they survive, but will they ever again play the sports they love.

Six years ago, when Rafael Acosta was experiencing unexplained soreness in his left arm, doctors told him there was significant nerve damage. One doctor even called for it to be amputated. At just 39 years old, Acosta was not yet ready for the impact being an amputee would have on his active sports life that included volleyball, softball and soccer. So he went for a second opinion, and then a third. After a battery of tests, doctors found more than nerve damage. They found cancer, a rare form that afflicts mostly children, but can lie dormant in some adults for decades.

The cancer, Primitive Neuroectodermal Tumor (PNET), created a mass of cancerous cells wrapped around the ulna nerve in Acosta’s left arm. Because this cancer typically manifests itself in the brain, the chances of it spreading were good.

To remove the mass, doctors had to sever the nerve. The nine weeks that followed of radiation dripping slowly into his body, burning good cells with bad, were among the most difficult of Acosta’s life.

But it would be the following 52 weeks, a year’s worth of chemotherapy treatments that would prove a lesson in patience.

Acosta relied in part on his teammates to help, sometimes with even simple tasks like making sure the bills were paid.

“A lot of my friends, who I didn’t realize I was even that close to, really came to my rescue,” he said.

But it wasn’t easy. Acosta reported to the doctors every three weeks for chemotherapy. To administer the treatment, they placed a tube in his chest that he could not remove until all the treatments were complete.

In the days immediately following each treatment, “All I could do was throw up,” he said.

Acosta was committed, though, not to die, and not to stop. “I was completely determined not to hide in the corner,” he said.

Even though the treatment regimen continued through his softball season, Acosta wasn’t going to miss it. He turned to friend Jim Costello, a longtime coach of championship teams in the über-competitive B Division. Costello knew his friend needed to stay active, so he gave Acosta a spot on his team’s roster.

“I would just tape the tube down to my chest and go out and play,” he said. “One time, I played a game the day after my chemo treatment. I was in a fog.”

Now cancer-free for five years, Acosta says it’s been a long road back.

“First, I had to re-learn how to use my hand, and then my arm and then my whole body,” he said.

For David Lang, it’s a different story. Five months of chemotherapy and radiation slowly took its toll on his body, and he could no longer run or play tennis.

It was an “occasional breathing irregularity” that spurred a visit his doctor in 2003. He’d encountered it while training for the Rock-N-Roll Marathon. An X-ray showed a mass inside Lang’s chest cavity near his lymph nodes. A biopsy later confirmed the diagnosis, Hodgkin’s Lymphoma.

“I began a 12-week ‘Stanford V’ chemotherapy regimen on Nov. 5, 2003,” Lang said. A month of radiation therapy followed.

Prior to his diagnosis, Lang had been running for exercise and as a social outlet for more than 20 years, and had been competing in triathlons for more than 10 years. He was not used to his body not allowing him to do whatever he asked.

For support he drew heavily from friends he met at Front Runners & Walkers San Diego. Lang remembered fondly: “When I would go to my weekly chemotherapy appointments, I would be accompanied by a group of people. Even though what I was doing was horrible, the people made it a lot of fun.”

Lang said just as soon as his treatments were over, he slowly began pursuing both running and tennis.

Staying connected is key for athletes fighting for their lives. It serves as motivation to regain their health.

Lang, who is now 43, says his current diagnosis is that of a “cancer survivor.” Cancer-free since 2004, he runs and plays tennis regularly.

“It was important,” Acosta remembered. “In my soul I knew I needed to stay active, and be a part of life. Otherwise I would have just shriveled up and died.”

But not everyone is as lucky.

In 2005, David Koenig found a hard lump the size of a golf ball on the inside of his left leg. Doctors would diagnose it as melanoma.

He had surgeries to remove the tumor and later to remove the infected lymph nodes in his leg and the spot of cancer’s origin, the bottom of his left foot.

Koenig then underwent a regimen of experimental injections.

According to Allen Sanchez, president of the San Diego Tennis Federation, Koenig kept his spirits high during his battle.

“He would come out on Friday nights and play a set sometimes, and then just sit and rest,” Sanchez said. “He would come out because he had fun, and he wanted to be around his friends.”

Koenig thought he’d beaten the cancer. In July 2006, he won the first of his three championship titles in Tennis’ D Division.

One month later, he decided it was OK to celebrate turning 40 with a giant beach party. Though his birthday was in April, friends say Koenig waited to celebrate because at times he doubted he was going to make it that long.

In October 2006, Koenig would go on to win two more titles, one in doubles and one in singles.

However, just two short months later, he would return to the doctor, complaining of headaches. The cancer had returned, this time as aggressive brain tumors. A month of radiation therapy in January had no effect, and doctors told Koenig to make preparations.

On March 29, 2007, David Koenig lost his fight with cancer. On Monday, April 2, what would have been his 41st birthday, Koenig’s friends, family and tennis buddies attended his funeral services in San Diego.

By all accounts, Koenig was a competitor. When he took to the court he wanted to win.

Although cancer proved too difficult an opponent, Sanchez said Koenig remained optimistic he would come out on top.

Athletes like Acosta and Lang know stories like Koenig’s all too well. They also know it could just as easily have been them.

Acosta says surviving comes with a sense of duty.

“I remember a lot of players who weren’t as lucky as I was – who didn’t get through it, whether it was cancer or something else that took them. I feel really, really lucky that I can still be playing. In a way, I’m playing for them. I put them on my shoulders.”