For Garry Keller, the strangest thing about facing a life-threatening cancer is how healthy he looked and felt when it all began.

Back in 2016, Keller was in his early 40s and at his peak. He was a busy special education teacher, but still squeezed in daily CrossFit workouts. In the summer, he worked as a raft guide, and in the winter, he enjoyed snowboarding with his young son.

Then he found a swollen lymph node in his groin. Doctors soon diagnosed a rare form of skin cancer: mucosal melanoma, which fights within membranes that line cavities of the body. The odds weren’t good. Initially, he had a 20% to 30% chance of survival.

“Before I knew it, I was trying to find a way to fight the cancer and not feeling sick at all, but the doctors were saying I’m pretty sick,” he said.

He would spend the next two years battling a cancer raging inside his otherwise healthy, fit frame. To others, the cancer wasn’t noticeable — except that his once light-brown hair had turned stark white, resembling a Marvel superhero character. Keller enrolled in clinical trials and tried experimental drugs – anything to stay alive for his wife and now 16-year-old son.

Melanoma in the family

The news of cancer hit close to home. Just five years before Keller’s diagnosis, his father-in-law was diagnosed with melanoma. His wife’s father tried to fight it with trials and immunotherapy, but it didn’t work. So when Keller had to call his wife, Becky, to tell her he also had melanoma, it was all too familiar. But telling his son was even harder.

“He remembers grandpa reading stories to him, so as soon as we told him, he knew what was up,” Keller said. “We had to be matter-of-fact. But there was a piece of me that didn’t want him to think I was sick. … Even though there was that piece that wasn’t healthy, I wanted to show my son I can power through. That I’m OK. I’m not going to die today. I’d say that a lot to myself.”

What is mucosal melanoma?

Unlike the melanoma that afflicted Keller’s father-in-law, exposure to UV from the sun has nothing to do with mucosal melanoma. This aggressive skin cancer attacks the mucous membranes that line the cavities of the body, such as the oropharyngeal, vaginal or gastrointestinal tract.

And it is rare, with only one out of 100 melanoma diagnoses being mucosal.

“We don’t know much about why it develops or who is predisposed. Genetic drivers are different, and response patterns to immunotherapy are different compared to the more common cutaneous melanomas,” said Dr. Theresa Michelle Medina, a medical oncologist who specializes in cutaneous oncology at the University of Colorado Cancer Center on the Anschutz Medical Campus.

Keller’s cancer started in his rectum and spread to nearby lymph nodes, but it hadn’t metastasized beyond that. One of his first symptoms was rectal bleeding, but given his age, it was attributed to having hemorrhoids. In retrospect, it was due to his primary tumor. Traditional treatment would be a lymph node dissection followed by immunotherapy.

Keller wasn’t a fan of the low odds of traditional therapy, given the high risk for recurrence or distant metastasis despite surgical therapy, and the risk that he could lose the opportunity to continue to be active and make lasting memories with his son was too high for him.

“I love snowboarding with my son and going on multiday rafting trips. If they started taking organs … what if I lose that?” Keller said.

Keller and his doctors decided to take a different route: roll the dice and hope for better odds in the experimental world than in the known world, wrote his wife, Becky, in her blog, “Life according to a paranoid optimist.”

Having been alongside his wife during her father’s battle with melanoma, Keller knew there was only one place he wanted to go to beat those odds.

A Comprehensive Center for Rare Melanoma

Rare melanomas, such as mucosal melanomas, are not well understood, and current melanoma treatments are less effective. Medina and her colleagues at the Center for Rare Melanoma at UCHealth University of Colorado Hospital on the Anschutz Campus are dedicated to understanding and treating these rare melanomas.

Keller began working with Medina.

“There were two drug therapies approved that showed to be effective, but they also carried high rates of side effects,” she said. “There were clinical trials ongoing at the time with another promising combination that was much better tolerated. People were having good responses and not having the immune toxicity that goes along with it.”

A month after his 2016 diagnosis, Keller started his first clinical trial, which aimed to determine the efficacy of a combined treatment of Epocadastat and Nivolumab.

The emotional side effects of being diagnosed with mucosal melanoma

As Keller continued to fight for his life, most people were oblivious to the cancer raging inside his body.

“It was the hardest part to overcome,” Keller said. “I didn’t feel sick. It was hard to believe what these doctors were telling me. It’s overcoming those physiological pieces.”

Patients with melanoma often struggle with this, Medina said.

“They don’t typically do chemo, so they don’t have the same outcomes as others, such as losing their hair. So that means when they are out in the community, they don’t look like they have cancer,” she said. “They feel lucky that they don’t have to deal with those side effects, but then they discount the experience they have to go through.”

Through most of it, Keller continued to work as the co-director of a special education program. He continued to work out at his CrossFit gym daily. And he took his son snowboarding and rafting.

“Getting to work and doing something; not sitting home and feeling sorry for myself, that helped,” he said.

Being involved in clinical trials for melanoma

For 22 months, Keller felt hopeful.

“I was doing well,” he said. “Then all of a sudden, I wasn’t. It grew again and was aggressive.”

Keller and his UCHealth team switched gears and tried another study, but after a few months, the results were disappointing, and the side effects left Keller feeling horrible.

Then Keller enrolled in a new trial.

The TIL trial for melanoma

“I was patient number one,” Keller said of the Tumor Infiltrating Lymphocytes (TIL) trial. “They didn’t know what was going to happen, but it was either do or die for me, so I wasn’t thinking of that.”

The National Cancer Institute study involved collecting white blood cells from a patient’s tumors, growing them in the laboratory in large numbers, and then returning them to the patient. These cells are called tumor-infiltrating lymphocytes.

Surgery is required to get the patient’s cells. Then they are given a round of chemotherapy to prepare their immune system to accept the white blood cells.

“They only wanted to get the cells fighting cancer because what they’ve found before, with similar treatment, is that if other immune cells are active, the body can’t support that,” Keller explained.

The patient’s white blood cells grown from the tumor are then infused back into the patient’s body. Concurrently, the patient receives a chemotherapy drug to boost their immune system’s response against white blood cells. Keller had eight total immune-boosting treatments.

Eight months into the trial, scans showed a lesion that appeared to be enlarging. But it turned out to be an inflammatory reaction and not melanoma, Medina said.

Returning to a cancer-free life

Keller was supposed to remain in the TIL trial for three years with scans every three months, but about a year in, every scan showed he was cancer free.

“I was free and clear, so at that point I left the study,” he said.

He now gets scans every six months, along with an office visit with Madina.

Keller still rafts, snowboards and does CrossFit. When he turned 50 in August 2025, he decided to add mountain biking to the mix. He’s now an assistant principal and spends most of his spare time cheering on Boden at swim meets.

The sense of doom that once shadowed Keller has faded, and the urgency to make the most of every second is no longer top of mind. The only reminder of his cancer is his bright white hair.

“My son thinks I’m a superhero, a Marvel character,” he said.

And considering Keller’s fight against something he couldn’t see or feel, it’s a title he has earned.