Merkel Cell Carcinoma Treatment

Merkel cell carcinoma (MCC) is a rare and aggressive type of skin cancer that develops from Merkel cells, a type of cell in the skin that is thought to help sense touch. MCC is most common in people over 50 and is more common in people with fair skin and exposure to a lot of sun.¹

How is Merkel cell carcinoma treated?

Many treatments are available for MCC, including surgery, radiation therapy, and drugs. The type of treatment that is best for you will depend on the size and location of the tumor, whether the cancer has spread to other parts of the body, and your overall health.¹

Surgery

Most Merkel cell carcinomas (MCCs) are treated with surgery. Different procedures depend on the tumor size, location, spread, and a person’s health.¹

Wide excision

During wide excision, the surgeon removes the tumor and a surrounding margin of healthy tissue. The amount of tissue removed depends on the size and location of the tumor. Wide excision can cure MCC if it has not spread beyond the skin.²

Mohs surgery

Mohs surgery is a skin cancer surgery used to remove the tumor and keep as much of the surrounding healthy skin as possible. It is done by a doctor who has special training in Mohs surgery.²

During Mohs surgery, the doctor removes the visible tumor and some healthy skin around it in thin layers, one at a time. The removed tissue is then examined under a microscope to see if any cancer cells are present. If cancer cells are found, the doctor removes another thin layer of skin and examines it under the microscope. This process is repeated until no cancer cells are found.²

Lymph node dissection

In this surgery, the surgeon removes the lymph nodes closest to the tumor.²

Radiation

Radiation therapy can be used to treat MCC. It can be used in these situations:³

• To kill any cancer cells that might be left behind after surgery. This is especially important if the removed tumor is big or the doctor is unsure if it was all taken out.
• If surgery is not an option, like if a person is not healthy enough or the tumor can not be removed all the way.
• To treat the lymph nodes near the tumor. Radiation therapy may be used if cancer is found in the lymph nodes. This can be done after or instead of removing the lymph nodes.
• To treat tumors that return after surgery.
• To help shrink or slow the growth of the cancer.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to kill cancer cells. Chemotherapy can be used to treat certain forms of MCC that have spread to other parts of the body.⁴

Chemotherapy drugs may be combined with other treatments, such as surgery or radiation therapy. It is usually given as a series of treatments called cycles. Each cycle usually lasts for a few weeks, and there is a break between cycles for the body to recover.⁴

The number of cycles a person receives will depend on the cancer stage and overall health.⁴

Immunotherapy

Immunotherapy is a cancer treatment that uses the body's immune system to fight cancer cells. This type of treatment may be used for certain forms of advanced or metastatic (has spread to other parts of the body) MCC. Immune checkpoint inhibitors are a form of immunotherapy.⁵

Immune checkpoint inhibitors

The immune system has built-in processes to prevent it from attacking healthy cells. These "checkpoints" are proteins on immune cells that act like switches. The immune system does not attack healthy cells when these switches are turned off.^5,6

Cancer cells can sometimes use these checkpoints to their advantage. They can turn off the checkpoints, which prevent the immune system from attacking them. This allows cancer cells to grow and spread without being detected by the immune system.^5,6

There are new treatments for cancer, including MCC, that target these checkpoints. These are known as checkpoint inhibitors. These treatments can help the immune system to start attacking cancer cells again. This can lead to better outcomes for people with MCC.^5,6

As of April 2025, the immune checkpoint inhibitors that may be used to treat certain forms of MCC include:⁵

• Bavencio® (avelumab)
• Opdivo® (nivolumab)
• Keytruda® (pembrolizumab)
• Zynyz™ (retifanlimab)

There is no one-size-fits-all treatment for MCC. The best treatment for you depends on your situation and treatment decisions made with your doctor.