There are a number of reasons why melanoma comes back.
Why melanoma comes back
According to Cancer Research UK, if the melanoma is low risk, meaning it is less than .76 mm thick, then there is very little chance that it will return. But if the melanoma is medium risk (.76 mm-1.5 mm) or high risk (> 1.5 mm thick) then the risk that it will return is higher.
If the melanoma reached advanced stages, there is also a higher risk of recurrence or, for some, treatment may never stop completely.
Recurrence of melanoma
While the exact reason why melanoma recurs is not clear, it can sometimes be a result of lingering cancer cells in the skin that were missed in the initial treatment. People who have had melanoma before are also at greater risk for developing melanoma again in other areas of the body.
These new melanomas are called second primaries. This is due to genetic factors, the amount of sun exposure received and the past immune system response.
The importance of the follow-up
Attending regular follow-up appointments with a doctor or dermatologist is key to catching any recurring melanomas early before they have a chance to spread or worsen.
A doctor will advise follow-up appointment timing based on the specifics of each individual patient, but the frequency of follow-up appointments are usually based on the stage the melanoma was in when it was treated.
DermNet New Zealand provides an overview:
· Stage I melanoma – follow-up visit every year for the next 10 years
· Stage II melanoma – depending on the severity of melanoma in this stage, follow-up every 4–6 months for 2–3 years and then once every year up to 10 years
· Stage III melanoma – every 3 months in the first year, every 4 months in the second year, every 6 months until year 5, and then once a year until year 10
· Stage IV melanoma – as for Stage III but with additional visits as required
Taking the proper precautions by staying out of the sun and wearing sunscreen and protective clothing is the other key to help prevent melanoma from returning.
Read more about Skin cancer symptoms what to look out for, with pictures, to help you know what to look out for.