Merkel Cell Carcinoma – What You Need to Know

The death of singer/songwriter Jimmy Buffett is raising questions about skin cancer, and experts at Thompson Cancer Survival Center are providing answers to spread awareness and promote prevention.

The skin cancer that led to Buffett’s death was Merkel cell carcinoma (MCC). Buffett was famous for his beach-loving, carefree persona and represented fun in the sun to a generation of fans before many understood the potential dangers of UV light and prolonged sun exposure.

“All advanced MCC cases are discussed at our weekly multidisciplinary conference discussion with review of imaging,” says David Chism, MD, medical director of clinical research at Thompson Cancer Survival Center. “Unlike most skin cancers, MCC is rare with less than 2,500 cases per year in the USA.”

By comparison, around 100,000 cases of melanoma are reported yearly, and the average number of squamous/basal cell skin cancers each year hovers around five million. Although it’s somewhat rare, incidences of MCC are expected to grow with an aging American population.

MCC is aggressive and has a high morbidity rate. Dr. Chism most commonly sees MCC in older men, those with light-toned skin, and it often develops in places on the body that receive a lot of UV light exposure. The immune-suppressed, such as people with HIV, solid organ transplant, or those with hematological malignancies, are also at a higher risk.

What to Look For

It’s always smart to be aware of changes in your skin, particularly new growths or moles that seem to change shape or color. MMC lesions appear a little differently than classic melanoma or squamous/basal cell skin cancer.

Dr. Chism says the lesions will be firm nodules, imbedded in the skin, and this type of cancer is known to grow rapidly.

“Patients with light skin tone and with a suspicious lesion which is rapidly increasing in size in a sun-exposed area should be evaluated by a dermatologist promptly for a complete skin and lymph node examination and imaging studies as needed,” Dr. Chism says.

A dermatologist can recommend patients with these lesions for a clinical trial, which Dr. Chism says is important because, with the relatively small number of cases diagnosed, there is much to learn about MCC.

“Clinical trial participation is strongly encouraged given the rarity of this population and the lack of robust randomized clinical data,” Dr. Chism says. “Participation in the clinical trials process is crucial for the continued advancement of systemic treatment options.”

Treating MCC

Current data suggests MCC responds to medications that work within the body to boost the immune system’s ability to fight off cancer cells. When medication doesn’t work on its own (or isn’t recommended to begin with), surgery, chemotherapy, and radiation come into play.

Grant Clark, MD, a radiation oncologist at Thompson Cancer Survival Center, sees an average of one or two MCC cases per year.

“Radiation is a treatment to reduce the risk of cancer relapse or to treat lymph node areas when needed, so my role is for patients that are deemed at higher risk of recurrence after surgery to often recommend preventative radiation to areas like the operative bed or site of the original tumor or the adjacent lymph node areas,” Dr. Clark says.

Trying to prevent recurrence is an important part of this cancer battle because MCC doesn’t go down without a fight.

“Merkel cell carcinoma tends to be more aggressive – meaning it more often comes back around the area where it was surgically removed and it spreads more often,” Dr. Clark says. “It is still often curable if caught early, but it spreads to other parts of the body – including lymph nodes – at a quicker pace and once it has spread it can be fatal.”

Dr. Clark says other types of more common skin cancers like basal cell carcinoma or squamous cell carcinoma tend to grow more slowly and are less likely to spread. 

“If you have a new skin lesion that is not resolving on its own and appears to be growing,” Dr. Clark says, “then that would be a time to see a primary care doctor or dermatologist.”

The Importance of Prevention

Both Dr. Clark and Dr. Chism emphasize the importance of prevention and early diagnosis. MCC sometimes appears on areas of the body that aren’t exposed to sunlight, but that’s an exception rather than the rule.

“Like with other skin cancers, and for overall skin health, using a sunscreen for prolonged sun exposure is recommended,” Dr Clark says, adding that he prefers sunscreens that are mineral-based.   

“Avoid mid-day sun exposure and use sunscreen with reapplication as needed,” Dr. Chism says. “Protect sun-exposed areas of the skin and avoid tanning beds.”

If you already have a history of other skin cancers such as basal cell or cutaneous squamous cell carcinomas, be especially vigilant about protecting your skin and be aware of any new growths or changes.   

“Acting early offers a higher likelihood of cure,” Dr. Chism says.