When you think of treatment for skin cancer, you reasonably imagine a patient just undergoing surgical excision—cutting out the tumor from the skin. This is the first treatment people with skin cancer will undergo, and for some patients, that’s all they will need.
However, melanoma may require more treatments, known as adjuvant therapies. “Adjuvant therapy for melanoma is used after you’ve done a complete surgical excision, and now you’re trying to help improve the chance of disease-free survival for the patients,” says Kaveh Alizadeh, MD, a plastic and reconstructive surgeon in New York.
Melanoma is more likely than other types of skin cancers to metastasize, or spread to other parts of the body. Once melanoma is metastatic, it requires more traditional cancer treatments, like immunotherapy and targeted therapy, to attack the cancer cells within the lymph nodes and other internal organs.
By stage III melanoma, about half or more patients have detectable melanoma cells circulating in the blood after surgical excision of the visible tumor, according to Jeffrey Weber, MD, PhD, medical oncologist and melanoma researcher at Perlmutter Cancer Center at NYU Langone Health.
“The immune system is just barely holding [the cancer cells] in check, and if something happens to make them just go over the edge, all of a sudden those tumors will grow,” says Dr. Weber. This is where adjuvant therapies come in: They’re a secondary treatment (after surgical excision) to target those circulating melanoma cells that have gone beyond the skin.
Types of Adjuvant Therapies for Melanoma
The goal of adjuvant therapies for melanoma is to reduce the risk of melanoma recurrence. If any cancer cells survive treatment—despite the oncologist’s best efforts—they can rapidly multiply and potentially form a tumor over time.
The two main types of adjuvant therapies used to treat melanoma include immunotherapy and targeted therapy, according to the American Cancer Society (ACS).
Immunotherapy helps the body’s own immune system recognize and attack cancer cells more effectively. For melanoma, oncologists use a type of immunotherapy called checkpoint inhibitors. These target a protein on the T cells (a part of the immune system that attacks threats to the body), and that protein helps activate the immune response against cancer cells. Find out exactly how checkpoint inhibitors help treat melanoma here.
Immunotherapy is usually the first adjuvant therapy used after surgical excision, according to Dr. Weber. “If you develop a new tumor that can be surgically removed to render you free of disease, that’s when you get to targeted therapy,” he says.
Targeted therapy recognizes gene mutations (most commonly to the BRAF gene) that are the result of melanoma. Targeted therapy drugs target cells that carry specific proteins related to these gene mutations, so it’s able to attack cancer cells more precisely than older methods like chemotherapy, and cause fewer and less severe side effects.
Oncologists may also use chemotherapy or radiation therapy, but these methods are less common after the introduction of immunotherapy and targeted therapy, which are more effective.
Chemotherapy attacks all rapidly dividing cells indiscriminately, so it can attack healthy cells and cause severe side effects. It is sometimes used in combination with other adjuvant therapies to make them more effective. Radiation therapy uses X-rays to kill cancer cells, and it is sometimes used if surgery is not an option, according to ACS.
After Adjuvant Therapies for Melanoma
Adjuvant therapies for melanoma typically last for a period of 12 months. The patient may have to come in every two to four weeks for the treatments. After that period, patients are monitored regularly to check for the presence of melanoma cells.
Worries about melanoma recurrence are common for patients, even after undergoing adjuvant therapy. The magic number is five years: “95 percent of all the relapses will have occurred by year five,” says Dr. Weber, “and at year five, you feel like you’re pretty close to being out of the woods.”
It’s easy to worry that the melanoma could still come back after year five, but Dr. Weber encourages patients to get on with their lives. “I tell patients, ‘Go out, [have] a glass of champagne, celebrate. You got to year six. You’re free of disease,’” says Dr. Weber.