Outcomes and Monitoring
Can Merkel cell carcinoma (MCC) return?
Cancer that comes back after treatment is called a recurrence. If you have completed treatment and there are no more signs of cancer in your system (the disease is undetectable on exam or scans), but later Merkel cell carcinoma (MCC) is found in your body, that is considered a recurrence of MCC—even if it’s in the same spot as before.
There are three aspects related to recurrence that will be discussed in this section:
- Recurrence – cancer that comes back
- Risk of Recurrence – the percent chance the cancer may come back
- Recurrence-free survival – how long patients live without their cancer returning
Who is at risk for recurrence?
All patients have some risk that their cancer could return, but not every patient will have a recurrence. The chance that a patient’s MCC will come back depends on many factors, such as:
- The stage of your MCC when you were diagnosed
- Your age
- Where your original cancer was located
- The treatments you had and when you had them
- How your cancer responded to those treatments
- Your overall health and other medical conditions
All of these things can affect your risk of recurrence.
Why is risk important?
Your doctor will think about your personal risk when helping you make a treatment plan. For example, patients with a very low risk of recurrence may not need some treatments that are recommended for higher-risk patients. <Learn more about treatment decisions>
Knowing a patient’s estimated risk of recurrence also helps doctors determine how closely to follow them for continued check-ups after their initial MCC treatment. The goal of these monitoring visits is to catch any sign of a recurrence early. Patients with a higher risk of recurrence may have more frequent monitoring visits. <Learn more about monitoring>
What makes recurrence more likely?
Your personal risk depends on many factors. Doctors use this information to plan the right level of monitoring and follow-up for you. It’s important to talk with your doctor about what these risk factors mean for you, and work with them to make a monitoring plan to watch for any signs that the cancer might come back. Staying informed, having regular check-ups, and using blood surveillance tests can help you stay prepared.
Tumor type Virus-negative tumor Tumors that do not contain MCPyV have a greater chance of returning after treatment | Immune status Weakened immune system Conditions like HIV/AIDS, organ transplant, or immune-suppressing drugs raise risk |
Tumor size Large tumor (>2 cm) Larger tumors at the time of diagnosis are associated with higher recurrence risk | Stage at diagnosis Higher stage = higher risk Stage is the strongest predictor of whether MCC is likely to come back |
Within 2 years
80%
About 80% of all MCC recurrences show up within the first two years after diagnosis
Within 3 years
95%
About 95% of all recurrences happen within the first 3 years after treatment
Average recurrence
40%
On average, MCC recurs in 40% of patients after treatment
Evaluating risk of recurrence for MCC
Your “risk of recurrence” is the chance your cancer will come back in the future.
Doctors use information from other patients to help estimate your risk. They look at patients whose MCC is similar to yours to see how often their cancer came back and how long it took to come back. This is called “recurrence-free survival” data. By studying these patterns, doctors can better predict how your MCC might act.
From this data, we know that:
- Risk depends a lot on the stage of cancer when it was first found and treated. The higher the stage, the greater the risk that MCC will come back. <Understand the stages of MCC>
- Most recurrences happen within the first 3 years after treatment. About 95% of recurrences happen during this time. After 3 years, the risk is much lower.
The deep dive below shows how cancer stage affects the chance of recurrence in MCC.
Doctors and patients may also explore the MCC Recurrence Risk Calculator to estimate their personal risk based on details unique to each case.
CLF - Adjuvant Chemotherapy
Sometimes, new symptoms tell you or your doctor that MCC has grown back. These may include a new bump on your skin or a new swollen lymph node. If you find a new bump or swollen lymph node, tell your doctor right away so they can schedule a biopsy to see if it is MCC or something else.
Other times, there are no obvious physical symptoms or signs of a recurrence that you can see or feel. That’s why doctors will continue checking you after treatment, using scans and blood tests. This is called monitoring. <Learn more about monitoring>
Recurrence risk calculator
This recurrence risk calculator was created using real patient data and gives patients and doctors a more personalized estimate of MCC recurrence based on a patient’s individual characteristics.
This tool is meant for patients who have not had an MCC recurrence and who have not received adjuvant immunotherapy.
Disclaimer: This tool is intended for informational purposes only and has not been created or validated for patients in the following categories. The calculator may not be accurate if you have ever:
- Been treated with an immunotherapy
- Had a recurrence of MCC in the past
- Had a molecular recurrence (e.g., a positive ctDNA or increased AMERK titer)
- Had a spontaneous regression (your MCC went away or decreased in size without treatment)
Patients in these categories should work with their healthcare providers for individualized assessment and recommendations.
MCC recurrence risk calculator
The risk calculator uses the time since your first treatment, which is usually surgery and/or radiation. You should enter your date of diagnosis, and the calculator will add 90 days, since most people finish their first treatment about three months after being diagnosed.
The model is based on data published in 2022 by McEvoy, et al. If you have questions or feedback, please email [email protected].
The model has been validated for predictions up to 5 years after initial treatment and for ages 11-98. The predictions are only applicable to those who have not recurred since their primary MCC diagnosis. Initial treatment is assumed to be completed 90 days after diagnosis.
Model last updated: 2022-08-09 20:00:47; n = 618
Disclaimer: The risk calculator does not constitute medical advice, but is designed as an indicator of risk that may help you and your physician make more informed decisions based on the experiences of patients with risk that is similar.
Survival outlook
Survival and disease recurrence are two important ways doctors understand and measure what might happen after someone is diagnosed with Merkel cell carcinoma (MCC).
- Recurrence means when the cancer comes back
- MCC-specific survival refers to how long you may live following an MCC and your likelihood of not dying from this cancer
It is important to know that survival expectations are not the same for everyone. Your healthcare team will help you plan for what to expect, based on your own specific tumor characteristics and risk factors.
Stage at diagnosis
How long a person lives after being diagnosed with MCC depends a lot on the stage of the cancer when it was found. Doctors will tell you the stage of your cancer when you are first diagnosed, by looking at many factors such as the size of the tumor and where the cancer is located. Knowing this can give you a better idea of what’s to come.
People whose cancer is only in the skin or lymph nodes (local or nodal disease) usually live longer than those whose cancer has spread to other parts of the body (distant/metastatic disease). <Learn about the stages of MCC>
Local
Stage I-II
Cancer only in the skin—generally the best survival outlook
Nodal
Stage III
Spread to nearby lymph nodes—intermediate survival outlook
Distant
Stage IV
Spread to other organs—the most challenging survival outlook
The role of immune health in survival
People with weakened immune systems—particularly those with T-lymphocyte problems such as HIV/AIDS, organ transplant recipients on immunosuppressive drugs, or patients with chronic lymphocytic leukemia (CLL)—have a lower survival outlook than those with healthy immune systems. Immune suppression also makes a person more likely to develop MCC in the first place.
Monitoring your MCC
After you finish your initial treatment for MCC, your doctors will want to check on you regularly to see how you’re doing and make sure there are no signs that the cancer has come back or spread. This regular follow-up is called monitoring or surveillance.
It’s important to keep in close contact with your care team after treatment. Your doctor will do regular skin and lymph node exams, and may order blood tests or scans to look for any signs of MCC returning. They will also review your medical history and check for any symptoms or changes that could suggest a recurrence.
The frequency at which you are monitored and get scans, blood tests, or see your doctor, will depend on the risk of your MCC coming back. For example, some patients who have a low risk of recurrence and have spent many years MCC-free may only get check-ups once a year. On the other hand, some patients with a high risk of MCC coming back or with other risk factors like weakened immune systems might need more frequent check-ups, scans, or blood tests, especially for the first couple of years after their diagnosis.
However, everyone who has been treated for MCC should be monitored, no matter their risk level. Regular monitoring helps your doctors find any signs of the cancer coming back early, even if your risk is low. Finding cancer early gives you the best chance for successful treatment and helps prevent it from becoming more serious. By working closely with your care team, you can stay as healthy as possible after treatment.
| Physical exams | Imaging | Blood tests |
Physical exams involve looking at and feeling your skin, body, and lymph nodes to see if there are any suspicious changes. For example, a physical exam that reveals a new skin lesion, an enlarged lymph node, or an enlarged liver may be a sign that the MCC has come back or spread. When cancer spreads to other places in the body, away from its original location, it is called metastatic. A lesion (or skin bump) of metastatic MCC may appear as a 1-3 cm skin-colored or red-purple bump that feels firm, is possibly located near the primary lesion, and grows rapidly over a period of 2-4 weeks. | Imaging is when doctors use scans to see what’s happening inside your body. Types of imaging include CT (computed tomography) scans, X-rays, MRI (magnetic resonance imaging), PET (positron emission tomography) scans, and other bone scans. When monitoring for MCC, you may have scans done if the ctDNA blood test or serology blood test indicate a concern, or if something is felt on your physical exam. | Blood tests should also be done to check for signs of recurrence or metastases. These include ctDNA tests, and, in some patients, AMERK serology tests. |
Circulating tumor DNA (ctDNA) test
The ctDNA blood test is a simple blood draw that should first be done around the time of diagnosis, then typically every 3 months during the monitoring phase to check for signs of MCC in the body. Some patients may take this test more often during high-risk periods of time.
The test looks for very small (microscopic) pieces of cancer DNA that have been “shed” from tumor cells and then circulate in the blood stream. These pieces are harmless, and having them circulating in the blood does not mean the cancer is spreading through the blood. However, if these pieces are in the blood, that is a sign that there is Merkel cell carcinoma somewhere in the body.
This test can tell you that MCC is detectable in your body, often several months before an MCC recurrence can be seen on any imaging scans. Patients who get regular ctDNA tests after treatment can avoid extra scans and may find an MCC recurrence sooner.
MCPyV serology testing (“AMERK” test)
Patients should have already taken a type of blood test called a serology test, or oncoprotein antibody test, around the time of diagnosis. This test looks for special antibodies in the blood that appear in some people as a reaction against Merkel cell polyomavirus (MCPyV), the virus that causes most MCC tumors. The blood test can also be used for monitoring, but only for patients who had a positive first serology test. <Find more information related to the initial serology test>
An introductory video on YouTube
We created a short video on YouTube <video overview of the Merkel virus serology test> that explains how the Merkel virus serology test (called AMERK) works and how it helps doctors monitor MCC patients.
Continue to get repeat serology tests every 3 months to check for signs of MCC recurrence.
- A person’s antibody levels usually drop by about 90% in the first year after treatment and keep going down; but if the cancer returns, the levels go up quickly again. You will continue to take serology tests over time to be alerted if your levels rise.
- Importantly, it is the percent change in your antibody levels, not the actual value, that indicates whether you may be having a recurrence. Increases in your antibody levels greater than 30% are concerning for a recurrence and your doctor should be notified promptly.
- Depending on the stage of the disease and other risk factors, your medical team may decide to reduce the frequency of testing, or discontinue testing, after 3-5 years of monitoring.
This means you do not make these antibodies. Because of this, you cannot be tested for antibodies as a part of your monitoring, because you will not make these antibodies even if your MCC comes back.
- You won’t need any additional serology blood tests. You will, however, need to be monitored closely. Not having antibodies means you have a higher risk of recurrence, so you’ll need imaging scans or blood tests for ctDNA, as described above.