Chemotherapy for Merkel Cell Carcinoma (MCC)

Chemotherapy (chemo) for Merkel cell carcinoma uses anti-cancer drugs that are most often given into a vein (IV) or given by mouth. These drugs travel through the bloodstream to all parts of the body. This makes chemo useful for treating cancers that have spread to other organs.

When is chemotherapy used for Merkel cell cancer (MCC)?

Chemo is most likely to be helpful for Merkel cell cancer that has spread to other parts of the body. In the past, chemo was often the main treatment for MCC that had spread. But newer immunotherapy drugs tend to work better, so they are now more likely to be the first treatment for advanced cancers.

Chemo might still be used in some situations to treat advanced MCC, such as:

• If a person can't have immunotherapy for some reason.
• If the cancer is no longer responding to immunotherapy.

Which chemo drugs are used to treat Merkel cell cancer (MCC)?

Merkel cell carcinoma (MCC) is rare, so it’s been hard to study using chemotherapy to treat it in clinical trials. Because of this, doctors often use chemo drugs that have been helpful in treating other types of fast-growing neuroendocrine tumors. The most common chemo drugs for MCCs that have spread include:

• Cisplatin
• Carboplatin
• Etoposide
• Topotecan

Most often, either cisplatin or carboplatin is used, often along with etoposide. Topotecan by itself tends to have fewer serious side effects, so it might be a better option for some people who are older or have other serious health problems.

Another combination of drugs that may be used is called CAV, which includes cyclophosphamide, doxorubicin (Adriamycin), and vincristine.

These drugs are given into a vein (IV), usually once every few weeks. They can often shrink MCC tumors for a time (or at least slow their growth and spread) and help relieve some symptoms. But after a while the cancer tends to start growing again.

Possible side effects of chemotherapy for Merkel cell cancer (MCC)

Chemo drugs can cause side effects. These depend on the type and dose of the drugs given and how long they are used. Common side effects can include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Diarrhea or constipation
• Increased risk of infection (from having too few white blood cells)
• Easy bruising or bleeding (from having too few blood platelets)
• Fatigue (from having too few red blood cells)

These side effects usually go away over time once treatment is finished.

Some drugs can have other effects as well, so be sure to talk with your cancer care team about what to expect.

There are often ways to lessen these side effects. For example, drugs can help prevent or reduce nausea and vomiting. Tell your cancer care team about any side effects or changes you notice while getting chemo so they can be treated right away, before they get worse.