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Skin cancer types: Merkel cell carcinoma diagnosis & treatment

Merkel cell carcinoma (MCC) is a rare cancer that requires specialized knowledge and equipment to find it. For this reason, the American Academy of Dermatology (AAD) recommends that you ask whether your doctor:

If you are diagnosed with MCC, dermatologists recommend that a specialized medical team with experience treating MCC deliver your care. This team should include doctors with expertise in different fields of medicine, such as surgical oncology, radiation oncology, medical oncology, and dermatology.

You can find a specialist at merkelcell.org: Find a specialist

Dermatologists recommend a specialized medical team with experience treating Merkel cell carcinoma deliver your care

Merkel cell carcinoma is a rare skin cancer that requires specialized knowledge to diagnose and treat.

Close-up of a female doctor looking through a microscope

How is Merkel cell carcinoma diagnosed?

When a doctor who has expertise in diagnosing MCC suspects that you may have this rare skin cancer, the diagnosis involves these steps:

  1. Your doctor looks at your skin and feels the lymph nodes closest to the growth that could be MCC. It’s important to feel the lymph nodes because MCC is an aggressive cancer that can spread quickly.

  2. If the tumor looks like it could be MCC, your doctor will remove all (or part of it) so that the tumor can be examined under a high-powered microscope. Special techniques are required to find MCC, so the doctor who will look at it under a microscope should be an experienced dermatopathologist.

  3. If the dermatopathologist finds MCC, your doctor may recommend that you have a surgery called a sentinel lymph node biopsy (SLNB) or a procedure called a fine needle aspiration biopsy. These biopsies can tell your doctor whether the cancer has spread to the nearest lymph nodes. When MCC spreads, this is often where it travels to first.

  4. Your doctor may also recommend medical testing, such as magnetic resonance imaging (MRI) or positron emission tomography (PET) scan. This can tell you whether the cancer has spread.

None of the above treats the cancer. They are used to determine the stage of your cancer. The stage tells your doctor how far the cancer has spread.

Stages of Merkel cell carcinoma

Stage 0
The cancer has not spread beyond the tumor. Your doctor may say you have in situ Merkel cell carcinoma.

Stage 1 or Stage 2
The cancer has spread beyond the tumor into the nearby skin but not to the nearby lymph nodes or elsewhere. In stage 2, the cancer has grown deeper than in stage 1.

Stage 3
The cancer has grown deep, spreading to one or more nearby lymph nodes or nearby tissue.

Stage 4
The cancer has spread to a distant lymph node or other distant organ. For example, if Merkel cell carcinoma began on your scalp, it may have spread to the lungs.

How is Merkel cell carcinoma treated?

Your medical team will consider the stage of the cancer and your health when creating your treatment plan, which may include one or more of the following:

Surgery: This treatment is often recommended for MCC in stage O, I, II, or III. Also called surgical removal because it seeks to remove the cancer, your team may recommend excision or Mohs.

  • Excision: Your doctor cuts out the tumor and an area of normal-looking skin around the tumor. Removing some normal-looking skin helps to remove stray cancer cells.

    Your surgeon may also remove the nearby lymph nodes. If this is necessary, your surgery will take place in an operating room.

    After excision, your doctors may recommend that you have radiation treatments to kill stray, unseen cancer cells.

  • Mohs (pronounced “moes”) surgery: If you have an early MCC that has not spread to the lymph nodes, this type of surgery may be an option. Most MCCs develop on your head or neck, where it can be difficult to remove an area of normal-looking skin. There just isn’t a lot of extra skin on these parts of the body.

    With Mohs surgery, less tissue can be removed because the surgeon can see where the cancer cells stop during the surgery.

    Patients remain awake during Mohs surgery.

    To learn more about what’s involved in having surgery and when it’s recommended, go to What is Mohs surgery?

  • Lymph node dissection (also called a lymphadenectomy): During this surgery, which is performed in an operating room, your surgeon removes lymph nodes closest to the MCC. When your surgeon removes some of the lymph nodes, the surgery is called a regional lymph node dissection. Sometimes, all (or most) of the lymph nodes must be removed. This is called a radical lymph node dissection.

    Each of the lymph nodes that your surgeon removes will be checked under a microscope for cancer cells.

After surgery, some patients need reconstructive surgery because MCC can grow deep. Reconstructive surgery can often be performed immediately after the surgery to remove the cancer.

To lower the risk of the cancer returning after surgery, doctors often recommend having another type of treatment. Called adjuvant therapy, this helps to kill any remaining cancer cells. Radiation therapy is often the treatment given after surgery for MCC.

Radiation treatments: Some studies show that radiation treatments reduce the risk of MCC returning. Most patients begin radiation treatments within 4 weeks of having surgery.

If you have MCC in stage I, II, or III that surgery cannot remove, you may receive only radiation treatments.

Observation: If you are in poor health and the MCC is growing slowly, your medical team may recommend this approach. Observation means that doctors will watch rather than treat you. If the cancer starts to grow quickly, treatment will be considered.

Palliative (pal-ē-ah-tive) care: This treats the symptoms, such as pain, rather than the cancer. Patients with all stages of cancer may receive palliative care. The treatments usually given as palliative care for patients with MCC are:

  • Radiation

  • Chemotherapy

These can ease the pain when cancer spreads. One particular type of radiation therapy called brachytherapy, which involves inserting radiation implants into the body, is often used to ease pain caused by MCC.

Chemotherapy, while rarely used to treat MCC, can reduce pain and other symptoms. However, for people who are 65 years of age or older, it may be too toxic to be used for pain relief.

Immunotherapy: When MCC spreads, doctors often recommend this type of treatment. These medications can target and destroy cancer cells.

For patients with advanced (has spread) MCC, the results from this type of treatment have been encouraging. In a clinical trial of 88 patients with advanced MCC for whom other treatment had not worked, nearly 1/3 responded to a medication called avelumab (ah-vil-ah-mab). Responded means that the cancer either cleared or diminished. This response lasted for an average of 10 months, helping patients live longer.

The results from this clinical trial for avelumab led the U.S. Food and Drug Administration (FDA) to approve this medication for MCC in stage IV. In stage IV, the cancer has spread far from where it started.

Avelumab is first drug ever approved to treat to treat MCC. It’s currently approved for patients in stage IV who are 12 years of age or older.

Patients not helped by one medication may respond to another one

For this reason, doctors may add a second medication or switch medications.

Male patient handshakes with a female doctor after medical examination

Clinical trial: Other medications known as immunotherapies are being tested in clinical trials for MCC. For some patients diagnosed with MCC, joining a clinical trial may a treatment option.

What is the life expectancy for someone who has been diagnosed with Merkel cell carcinoma?

If you have MCC, many factors affect your life expectancy. Your age, other medical conditions, and stage of the cancer are just a few factors. For this reason, it’s impossible to predict how long one person who has MCC will live.

While it is impossible to predict how long one person will live, researchers can predict how long a group of people who have MCC will live. This is called “survival rate.” If you come across this term while looking for information about MCC, it is important to know what this term means.

Survival rate is “the percentage of people who will be alive within a certain time period, such as 5 years, after being diagnosed with a certain stage of MCC. Each stage has its own survival rate.

Before you search for these survival rates, it’s important to keep the following facts in mind:

  • Survival rates are estimates.

  • Each person diagnosed with MCC has unique characteristics, so your outlook may be very different from someone else who has the same stage of MCC.

  • Newer treatments, such as immunotherapy, are helping people live longer.

Another important consideration is your self-care after treatment. Protecting your skin from the sun and never tanning can help prevent a new MCC. Yet, studies reveal that many people continue their old habits after treatment and never protect their skin from the sun.

You’ll find out what dermatologists recommend after treatment for MCC at, Merkel cell carcinoma: Self-care.

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