Kirk Smith doesnt care much for the word awareness instead, he prefers the word hope.

The 54-year-old is training for a half Ironman triathlon in October while battling an aggressive, genetic-linked form of lung cancer that has a poor survival rate and no cure. He wants to inspire others, cancer patient or not, and make them believe that anything is possible, even in light of terminal illness.

Smith, who owns a graphic design and web firm in Athens, Ga., was diagnosed in December 2013 with stage 3B lung cancer, which means the disease had spread from his lungs onto the opposite side of his chest and into his lymph nodes. That stage of cancer has a 5 percent five-year survival rate, making it one of the deadliest cancers in the world.

Since his diagnosis, though, Smith has run countless 5Ks, 10Ks, half marathons, and sprint-distance races thanks to a longtime interest in such physical pursuits, but also due to a targeted drug that blocks the genetic mutation that caused the disease. Smith has never smoked cigarettes, which causes nine out of 10 lung cancers, according to the Centers for Disease Control and Prevention.

If you get cancer, its not automatically a death sentence, or that your-quality-of-life-is-going-to-crap sentence, Smith told FoxNews.com. Thats one of the biggest things for me: With targeted therapy, Im able to do this, and my quality of life has changed very little.

Smith is aiming to complete half of the PPD IRONMAN® North Carolina triathlon on Oct. 22, 2016, as part of team Free to Breathe, a Madison, Wisconsin-based lung cancer research and advocacy organization. A half Ironman, often referred to as an Ironman 70.3, involves about that many miles total: a 1.2-mile swim, a 56-mile bike ride, and a 13.1-mile run.

If I see a guy whos doing a half Ironman and know he has late-stage lung cancer, I would be inspired, but I also think Id be, Thats phenomenal how has cancer treatment gotten to this stage that that could be done? Smith said.

Smiths oncologist Cynthia Shepherd, an internist at the University Cancer and Blood Center in Athens, Ga., said she considers him not only a patient but also a friend.

Kirk is a special person to me, Shepherd told FoxNews.com. Its just exciting to see him hopefully as the face of Free to Breathe to help educate others about the importance of research.

Research led to the creation of the drug thats sustaining Smiths life.

He is part of the nearly 4 percent of Americans whose lung cancer stems from a genetic mutation. After undergoing genetic testing for about 200 mutations, he was diagnosed with ALK+ lung cancer, marked by an anaplastic lymphoma kinase genetic mutation.

“[Smith] was doing anything and is doing everything right in regards to exercise and eating right— and unfortunately, he still got lung cancer.”

– Cynthia Shepherd, Kirk Smith’s oncologist

He went to the emergency room after suffering from chest pain during a mild 30-minute run home from his office. Previous discomfort came and went during his runs, but when it felt more intense, he chalked it up to a pulled muscle. This time was worse.

It hurt so much, I had to stop. It felt like someone was stabbing me, he said.

Smith drove himself to the emergency room, at this point thinking a heart issue may have been the source of his pain. He didnt have a family history of lung cancer, and none of his immediate relatives smoked.

A pulmonologist took a tissue sample and scheduled a bronchoscopy several days later. On Dec. 26, 2013, Smith was diagnosed with the disease doctors found two tumors in his left lung, and the pain hed been feeling was one pinching a portion of the organ and cutting off blood supply.

That part of my lung is now toast, Smith said. If I hadnt gotten it checked, I may have gotten to stage 4 [lung cancer], which has an even worse survival rate, somewhere under 10 percent.

If Smith was diagnosed about a decade ago, doctors would have put him on a traditional cancer treatment regimen, with chemotherapy and radiation. But in 2007, scientists discovered the ALK mutation, following their identification of the EGFR and preceding the ROS1 two other genetic mutations linked with lung cancer. Doctors have noticed the ALK mutation usually affects people with Smiths profile: men who have had little to no exposure to tobacco, and who are active and healthy.

[Smith] was doing anything and is doing everything right in regards to exercise and eating right and unfortunately, he still got lung cancer, Shepherd said.

In 2011, the Food and Drug Administration (FDA) approved crizotinib, a drug developed to combat the ALK mutation. Smith took the drug from January to February 2014, and it halted his tumor from growing, but it also caused his liver enzymes to skyrocket to dangerous levels.

If your liver cant function, it can shut down and you can die of liver failure, Shepherd said. Even though [crizotinib] kills the cancer, it has this unique toxicity in the liver.

Shepherd tried restarting Smith at a lower dose but eventually switched him to ceritinib in May 2014, which the FDA approved the month prior. Ceritinib blocks the proliferation of cancer cells caused by the genetic pathway and its corresponding resistance to apoptosis, or the bodys ability to kill cells, effectively eradicating the cells and halting their growth. Unlike chemotherapy and radiation, targeted drugs like ceritinib kill only cancer cells, not healthy cells.

Smiths most recent CT scan about two years after being on the drug indicated clear lymph nodes and immeasurably small lung cancer tumors.

This shows what a remarkable drug it is and the importance of finding this mutation in people like Kirk, Shepherd said.

Although its uncertain whether Smiths diet and exercise have made his medication more effective, Shepherd believes its apparent that his lifestyle has helped suppress some of the drugs side effects, including nausea, diarrhea and vomiting.

Smith takes four pills a day, and usually if he takes one before he exercises, he doesnt have those problems.

Not only does exercise keep me healthy, but it helps my quality of life so Im not at work with bowel issues, Smith said.

“Obviously people look at him and feel inspired without even knowing what his situation is.”

– Ryan Marsh, Kirk Smith’s longtime friend and personal trainer

Ryan Marsh, a partner at Athens Personal Fitness in Athens, Ga., manages Smiths diet and rigorous training regimen. He goes on steady-paced morning runs that range from 5 to 8 miles six days a week. In the afternoons or evenings, hell do strength training twice, and among the five other days hell do swimming, or mountain or road biking. On Sunday, though, Smith does a trail run in the morning, a two- to three-hour road ride, plus an afternoon swim.

Since hes been on this new drug, the main side effect is muscle cramping, and thats just something almost a normal person would experience with some of the things he does, said Marsh, 37, who as Smiths accountability partner helps ensure he doesnt over-exert himself. But he seems to do a good job of dialing back the intensity when [the muscle cramps] come back.

To support his physical activity, Smith consumes about 4,000 calories a day, including one or two protein-rich smoothies. Marsh said that intake has helped improve Smiths immunity and achieve his fitness goals safely.

One of the coolest things about Kirk is he is so encouraging, said Marsh, who has been friends with Smith since 2008, before his diagnosis. Obviously people look at him and feel inspired without even knowing what his situation is.

Smith sees Shepherd for monthly checkups to ensure his liver enzymes arent too elevated and that his tumor is still suppressed. Targeted drugs like ceritinib are too new to know how much survival rates for patients like Smith have improved, but Shepherd said data indicate the drugs work for a few years.

It would not be a shock for [Smith] to hear me say that eventually the cancer will start growing, Shepherd said. When, we dont know. We wish we knew so we could catch it.

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