Know Your Options
Merkel cell carcinoma is rare and dangerous but treatable, especially when found at an early stage.
Because MCC is such an uncommon form of skin cancer, it is best to seek treatment at an academic center with physicians who have specialized expertise in caring for people with this particular disease. A multi-disciplinary team experienced in the care of MCC is recommended. Dermatologists, surgeons, medical oncologists and radiation oncologists need to confer to determine the best plan for a given case.
While treatment options for MCC depend on the stage of the disease and the overall health of the patient, treatment includes surgical removal of the primary tumor along with:
How it works
MCC is highly responsive to radiation, a localized treatment that uses high-energy rays such as X-rays or particles such as electrons to penetrate the tumors and destroy them or keep them from growing.
When it’s used
Radiation may be used for the following purposes:
- At the primary site: Depending on the site of the tumor, location and post-surgery margins, physicians may recommend radiation to treat the skin area around the primary tumor after surgery to try to destroy any cancer cells that may have been missed during surgery. Especially if it seems likely that the tumor may come back, because of its size or because the patient is immunosuppressed, radiation is often used on the site where the lesion was removed. This helps prevent recurrence or spread of the cancer to the local lymph nodes or beyond.
- At nodes or distant sites: If the MCC has spread to local lymph nodes, doctors may recommend removing some or all of the nodes and/or then treating the nodal site with radiation to reduce the risk of recurrence. Radiation can also be used on a large, inoperable tumor, to improve the chances it might shrink enough in size to be successfully excised. Tumors that are reduced in size by radiation may also be more treatable with immunotherapy.
If the cancer has reached an advanced stage, treatments including immunotherapy, chemotherapies and participation in a clinical trial may be recommended as potential options.
Immunotherapies boost the body’s ability to fight cancers by using synthetic versions of immune system proteins, or by enabling the release of cells that attack tumors. These therapies are effective when used alone or in combinations.
“Exciting new therapies are emerging.”
Sandra D’Angelo, MD
Memorial Sloan-Kettering Cancer Center
Checkpoint blockade therapy
In 2017, researchers achieved promising success in treating advanced stage MCC with a revolutionary immunotherapy treatment known as checkpoint blockade therapy.
Checkpoint blockade immunotherapies block molecules (proteins called PD-1 [programmed death-1] or PD-L1 [programmed death-ligand 1]) that prevent activation of T-cells – white blood cells that produce immune responses. Under normal conditions, this control mechanism helps prevent potentially dangerous autoimmune reactions. For MCC patients, the drug blocks these molecules, releasing the brakes on T-cells that can then attack the cancer.
These pioneering discoveries of how to control the anti-cancer immune response earned researchers the 2018 Nobel Prize in Medicine.
How it works
Avelumab was the first immune checkpoint inhibitor approved by the FDA (in 2017) for the treatment of adults and pediatric patients age 12 and older with metastatic MCC. This treatment blocks PD-L1 and essentially removes the brakes on the immune system, releasing T cells to kill MCC tumor cells more effectively.
Another immune checkpoint inhibitor, pembrolizumab, binds the PD-1 molecule, activating the immune system to attack MCC tumors. The therapy was approved in 2018 for adult and pediatric patients with locally advanced or metastatic MCC.
In 2023, the FDA granted accelerated approval to retifanlimab-dlwr, also a PD-1 inhibitor, as a treatment for adults with metastatic or recurrent locally advanced Merkel cell carcinoma (MCC). Its safety and efficacy were based on data from the POD1UM-201 trial that evaluated the treatment in adults with metastatic or recurrent locally advanced MCC who had not received previous systemic therapy for the disease.
Future treatment possibilities
The field of immunotherapy is evolving and growing, giving patients with MCC broader options and new hope for treating and managing the disease. Studies have looked at using immune checkpoint inhibitors in combinations for patients with advanced MCC, as well as with other treatments. Trials are ongoing.
How it works
Chemotherapy is a systemic approach to stop cancer cell growth using certain drugs that either kill the cells or stop them from multiplying.
When it’s used
Although MCC is responsive to chemotherapy (over half of patients’ tumors will shrink), responses are seldom durable (over half of tumors will start growing again by 90 days after starting chemotherapy). MCC often gains resistance and the tumor can start to grow again despite receiving chemotherapy. Furthermore, the immune system is somewhat suppressed by chemotherapy and side effects are also considerable.
The 2018 National Comprehensive Cancer Network (NCCN) guidelines list immunotherapy agents as preferred treatment options for patients with advanced MCC. Chemotherapy is now generally recommended for patients who are not eligible for immunotherapy or those who did not respond to immunotherapy.
Doctors can use chemotherapy in a “palliative” manner temporarily to decrease pain and improve comfort and mobility for patients.
Sandra D’Angelo, MD
Paul Nghiem, MD, PhD
Last updated: August 2022
Note: The information included on this website is medically reviewed and factually accurate. It is intended for educational purposes only. The treatment information on this page is not a recommendation or endorsement of any drug, device or treatment, nor does it suggest that any drug, device or treatment is safe or effective for you. If you have any questions about skin cancer treatments, please talk to your health care provider.