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In 2020, Sue, a 63-year-old living in Oregon, felt a small bump on her left wrist. After a biopsy and testing, she suddenly faced a life-altering diagnosis: Merkel cell carcinoma, a rare and serious type of skin cancer.
Sue, who wished not to use her last name, didn’t know at the time that the Pacific Northwest was home to one of the few research teams conducting research on the disease led by Paul Nghiem, MD, PhD, a dermatologist and the faculty founder and director of the Merkel Cell Carcinoma (MC3) Institute at UW Medicine. Thanks to their discoveries, Sue got the care she needed — and it saved her life.
Understanding Merkel cell carcinoma
Merkel cells are normal skin cells that help the brain sense touch. Merkel cell carcinoma happens when skin cells that look like Merkel cells become cancerous and grow out of control. It is far more aggressive and spreads much faster than other, more common forms of skin cancer, like basal cell carcinoma or melanoma.
An extremely common (and usually harmless) virus plays a key role in triggering most cases of Merkel cell carcinoma. It’s called the Merkel cell polyomavirus, and it was first discovered in 2008. Other causes include extensive sunlight and ultraviolet (UV) exposure, especially in people with fair skin.
Symptoms most often include a single red, pink or purple shiny bump that grows quickly. It usually doesn’t hurt, but it can sometimes break skin at the top of the bump and cause bleeding. These tumors can grow anywhere on the body but are commonly found on places most often exposed to the sun, such as the arms, legs, face and neck.
A difficult-to-diagnose disease
Another challenge is that Merkel cell carcinoma is easy to miss. Someone might notice a spot on their skin and not think twice about it, especially if they’re otherwise healthy, have no noticeable symptoms and have no family history of cancer — this was the case for Sue.
“I wasn’t aware of the existence of Merkel cell carcinoma until my diagnosis,” says Sue. “I barely heard of the more commonly known skin cancers, such as basal and squamous cell, and melanoma.”
Even doctors often miss Merkel cell carcinoma in patients because it typically does not look concerning initially.
“Merkel cell carcinoma was poorly understood, and it is commonly misdiagnosed, even now,” says Ankita Menon, a research study coordinator for the MC3 Institute.
That’s what prompted Nghiem to start a lab to do more research on it and to found the MC3 Institute in 2025. Currently, they are among the few places conducting research on tests and treatments for Merkel cell carcinoma.
How treatment helped save Sue’s life
After receiving the diagnosis, Sue says she was unaware of the treatments available for this little-known cancer. To learn more about Merkel cell carcinoma, she searched online for information, which led her to the research being done by Nghiem’s team.
She discussed her findings with her dermatologist, who believed Fred Hutch was the best place to receive care; providers in Oregon lacked experience treating Merkel cell carcinoma. Her dermatologist then sent a referral for treatment at Fred Hutch, where she began care with Nghiem’s team, traveling to Seattle several times during treatment.
While cancer took a toll on her overall health, it also affected her life in smaller ways. For example, one motivation to complete her treatment was the chance to wear her watch normally again — she had been wearing it on her other wrist because of the tumor’s location.
Nghiem and his team removed Sue’s affected lymph nodes, and she underwent radiation treatment. Because Merkel cell carcinoma grows and spreads quickly, Nghiem’s team prioritizes getting patients treated more quickly than for most other types of skin cancer. From the first appointment to the completion of radiation treatments, it took less than 20 weeks.
“While it’s been a difficult journey, I dealt with the stress of Merkel cell carcinoma with levity and positivity, like drawing faces on my tumor until it slowly went away due to the radiation,” says Sue.
The radiation was effective, and no surgery was required to remove the tumor, avoiding any disfigurement where the tumor used to be on her wrist.
How research helped develop tests to detect Merkel cell carcinoma recurrence
Completing radiation wasn’t the end of Sue’s journey. An average of 40% of patients with Merkel cell carcinoma will experience a recurrence, so survivors need to undergo regular monitoring within the first five years to make sure it doesn’t come back.
Nghiem’s team has been using two technologies to monitor Sue. The first is called a circulating tumor DNA (ctDNA) test, which became available in the last five years and can detect DNA from the tumor in the blood should the cancer return.
The second test came from a discovery made by the MC3 team: their research found that many patients with Merkel cell carcinoma make antibodies — special blood proteins — against the virus that often causes the cancer.
“We realized that by measuring these antibodies in a blood test, we could discover early when their cancer was recurring,” says Nghiem.
This blood test, which was also developed at UW Medicine, became known as the anti-Merkel cell panel (AMERK) test.
“Rising antibody levels often signal that the cancer is returning, while falling levels can reassure patients that treatment is working,” says Candice Church, PhD, the director of scientific research at the MC3 Institute and a senior research scientist at the Nghiem Lab at the UW School of Medicine’s Department of Dermatology.
Sue submitted blood samples every three months to undergo these tests.
“My favorite number is zero, as it is the number of detectable Merkel cells in my ctDNA test since the diagnosis in 2020,” says Sue.
As of 2025, Sue has completed all monitoring and is still cancer-free.
The future of Merkel cell carcinoma research
Because of Merkel cell carcinoma’s aggressive nature and how quickly it can return, Nghiem says many patients face uncertainty about their disease.
“While we’ve made progress with tools like the AMERK blood test and new therapies, there’s still so much we don’t know about Merkel cell carcinoma,” says Nghiem.
This has been a hard few years for Nghiem and his team, though, because of the threat of federal funding cuts.
“Our main research grant was held up for many months without any stated reason,” he says. “It was not clear if it would move forward or not, but after about six months, we did receive the funding. That was a difficult time for our team, and it affected our ability to try to move forward against this disease.”
Because Merkel cell carcinoma is usually caused by a virus, studying it could lead to broader lessons about how cancers interact with the immune system.
“Continuing this research allows us to learn the broader principles of cancer and immunity that could also benefit patients with more common types of cancer,” says Nghiem. “This could help us design treatments that not only control cancers, but ideally prevent them from coming back,” says Nghiem.
Meanwhile, Sue is doing everything she can to raise awareness of the importance of research on Merkel cell carcinoma.
“I ask all of my doctors outside of Fred Hutch if they are aware of Merkel cell carcinoma,” says Sue. “Those who don’t know are aware now. This is my way of giving back to the MC3 team and any new potential Merkel cell carcinoma patients.”
