Melanoma is a type of skin cancer that develops in the cells that give skin its color. A dermatologist can remove and treat melanoma. However, it can return after treatment, becoming recurrent melanoma.
Melanoma is a rare but aggressive type of skin cancer. According to the American Cancer Society, only
This article explains recurrent melanomas, how to recognize them, why they return, and how to treat them.
Melanoma is a cancer that starts in the melanocytes. These cells produce melanin, the pigment that provides skin color. Melanocytes respond to UV light from the sun or tanning beds by making more melanin, causing a tan. However, UV light can damage the DNA of the melanocytes, leading to atypical cell growth.
This type of skin cancer is particularly aggressive, meaning that it can grow and spread to other organs quickly. Recognizing and treating melanoma early can prevent it from returning. However, melanoma can become recurrent if cancer cells survive the original treatment. This means that they may return.
Healthcare professionals refer to the original melanoma as the “primary melanoma.” A recurrent melanoma always grows from primary melanoma cells, even if it is not at the original site. If melanoma develops, it also
Most recurrent melanoma develops within 2–3 years of primary melanoma removal. However, melanoma can recur over 10 years after the original treatment. Remaining melanoma-free for over 10 years reduces the risk of recurrent melanoma, but it may still occur.
Recurrent melanoma can develop in the same location as the primary melanoma or elsewhere. If melanoma returns, it may appear in the following areas:
- the surrounding skin and tissue, known as isolated local recurrence
- just under the skin or nearby lymph vessels, known as in-transit recurrence
- the lymph nodes of the immune system, known as lymph node recurrence
- distant organs, known as distant recurrence
The clearest symptom of melanoma is a new spot or lesion on the skin that is changing. The following features of a mole may change:
- size
- shape
- color
The American Academy of Dermatology (AAD) and other organizations use the ABCDE rule to define the appearance of a melanoma:
- Asymmetry: Half of the lesion is different than the other.
- Border: The borders of the mole are ill-defined and irregular.
- Color: The color is different across the lesion and may include shades of brown, black, pink, blue, red, or white
- Diameter: Often, the spot is larger than 6 millimeters across.
- Evolving: The lesion’s color, size, and shape are changing.
The direct cause of melanoma’s DNA damage is unclear. However, certain factors make it more likely that a person will develop melanoma.
Melanoma
Other factors that increase the risk of melanoma include:
- older age, although melanoma is among the most common cancers in people under 30 years of age
- having many moles
- a lighter skin tone or hair color
- a family history of melanoma
- having a compromised immune system due to medications or immune conditions
- being female and under 50 years
- being male and over 50 years
While treatment aims to destroy all cancer cells, some may remain. These can keep dividing and grow into another melanoma.
Anyone who has had melanoma in the past has a higher risk of developing recurrent melanoma. A 2019 study of 700 people with primary melanoma found that
The risk of melanoma returning may depend on several features of the original melanoma, including:
- lesion thickness
- whether the sore was open
- whether the melanoma appeared alone or surrounded by smaller melanomas
- whether the melanoma spread to nearby lymph nodes
- the location of the melanoma — for example, the head or the neck may be more likely places for recurrence
- how quickly the tumor grows — rapid growth may be associated with recurrence
- the stage of the primary melanoma — the higher the stage, the more likely recurrent melanoma becomes
The different treatments for recurrent melanoma depend on several factors, including:
- the location of the cancer
- previous treatments and their results
- overall health
Surgery
A surgeon performs a procedure called a wide local excision. This can help for an isolated local recurrence that is less difficult to remove.
They will cut out the cancer and some of the regular skin around it. This may prevent the cancer from returning or spreading to other body parts.
Surgeons may also remove nearby lymph vessels or lymph nodes if an in-transit recurrence develops. They may also perform a biopsy of the lymph nodes if necessary.
Medications
Healthcare professionals may use the following treatments to treat recurrent melanoma that has spread beyond the original site:
These include injectable medications, infusions, vaccines, and creams. They activate the immune system to recognize or attack the tumor. Some drugs target specific proteins in cancer cells to make treatment more effective.
Specific treatments might include:
- Bacille Calmette-Guerin (BCG) vaccine injection into the tumor
- imiquimod cream
- direct injections of talimogene laherparepvec (Imlygic), a virus that kills cancer cells
- interleukin-2 (IL-2), a medication that boosts the immune system
- immune checkpoint inhibitors
Sometimes, healthcare professionals will use chemotherapy on a single limb if melanoma only affects one arm or leg. A cancer team may also recommend these medications to shrink tumors before surgery or kill remaining cells following a procedure.
People who have had melanoma in the past have a higher risk of other cancers than those who have not had melanoma, including different primary melanomas and other skin cancers. They are also more likely to develop cancers outside the skin, including the
- salivary gland cancer
- small intestine cancer
- breast cancer
- prostate cancer
- kidney cancer
- thyroid cancer
- soft tissue cancer
The 5-year survival rate refers to how likely a person with melanoma is to live for 5 more years compared to a person who has not had melanoma. This depends on several factors. However, statistics only apply to the stage of cancer at diagnosis.
According to the American Cancer Society, the 5-year survival rates for primary melanoma are
- Localized: More than 99%
- Regional, having spread to nearby tissue and lymph nodes: 71%
- Distant: 32%
Identifying recurrent melanoma early through regular checkups and self-examinations can help improve their outlook and reduce the effect of further recurrences.
There are several ways to help prevent melanoma and potentially its recurrence. These approaches can help reduce the risk or help people detect recurrent melanoma early enough to support a favorable outlook.
These include:
- Self-exams: After treatment for primary melanoma, people should examine the skin at home monthly. They can use a handheld mirror to carefully check the skin for changing moles.
- Regular examinations by a skin cancer specialist: A medical professional should check for changing or suspicious lesions every
3–6 months for a year after treatment. Checkups may be every 6 or 12 months after a year. - Reduced exposure to UV light: This includes wearing sunscreen with a high protective factor, covering areas of skin with loose clothing, and avoiding tanning beds. A person can also avoid direct sunlight between 10 a.m. and 2 p.m. when the sun’s rays are strongest.
People who have had melanoma in the past have a higher risk of recurrent melanoma. This type of skin cancer can return after treatment in the same area or spread to nearby lymph nodes and distant organs. A high-stage primary melanoma increases the risk of recurrent melanoma.
Treatment includes surgery to remove cancerous lesions and medications to involve the immune system in targeting melanoma cells.
People can recover from recurrent melanoma, and regular checkups and reducing UV exposure can help decrease the risk of recurrence.