Stage III melanoma represents a critical point in the disease where cancer has spread beyond the original skin site to nearby lymph nodes or surrounding tissues, but has not yet reached distant organs. Treatment decisions at this stage can significantly influence outcomes, combining surgical approaches with newer therapies designed to prevent recurrence and improve long-term survival.

What Stage III Melanoma Means for Your Treatment Journey

When melanoma reaches stage III, it means the cancer cells have traveled from the original tumor to nearby structures in your body. This is different from earlier stages where the disease remained confined to the skin. At this point, treatment goals shift toward removing all visible cancer through surgery and using additional therapies to target any remaining microscopic disease that could cause the cancer to return or spread further^[1].

Understanding your specific situation is important because stage III melanoma is divided into several subgroups labeled IIIA, IIIB, IIIC, and IIID. These classifications depend on factors like how thick the original tumor was, whether it had ulceration (broken skin when examined under a microscope), and how many lymph nodes contain cancer cells^[1]. Your treatment plan will be tailored based on these details, your overall health, and where the melanoma is located on your body.

The lymph nodes are small, bean-shaped organs that are part of your body’s defense system. They filter a fluid called lymph and trap harmful substances including bacteria, viruses, and cancer cells. When melanoma spreads to lymph nodes, it means cancer cells have moved through the lymphatic system, which is a network of vessels throughout your body that helps fight infection and remove waste^[1].

Sometimes, cancer cells are found between the original melanoma and the nearby lymph nodes. These deposits are called satellite metastases when they’re within 2 centimeters of the original tumor, or in-transit metastases when they’ve traveled more than 2 centimeters but haven’t reached the nearest lymph node^[3]. Understanding these patterns helps doctors determine the most appropriate treatment approach.

Finding Out If Lymph Nodes Are Affected

Before planning treatment, your doctor needs to know whether melanoma has spread to your lymph nodes. The most common way to check this is through a procedure called a sentinel lymph node biopsy. This test identifies and removes the first lymph node or nodes that drain fluid from the area where your melanoma was located. If cancer cells are found in these sentinel nodes, it indicates the melanoma has spread through the lymphatic system^[3].

The sentinel lymph node biopsy is typically performed at the same time as a wide local excision, which is the surgery to remove the melanoma along with a margin of healthy tissue around it. This combined approach allows your surgical team to address both the primary tumor and check for lymph node involvement in one operation^[3].

If your doctor can feel enlarged lymph nodes near your melanoma during a physical examination, you may have an ultrasound scan instead of or in addition to a sentinel node biopsy. During the ultrasound, sound waves create images of the lymph nodes, and your doctor may take a small tissue sample from any suspicious nodes to examine under a microscope for cancer cells^[3].

Standard Surgical Treatment

Surgery is the cornerstone of treatment for stage III melanoma when the cancer can be completely removed. The main surgical procedure involves removing the melanoma with a margin of healthy skin around it. The width of this margin depends on how thick the original tumor was. Thicker melanomas require wider margins to ensure all cancer cells are removed^[3].

When melanoma has spread to lymph nodes, surgeons perform a procedure called lymph node dissection or lymphadenectomy. This operation removes a group of lymph nodes from the area where the melanoma has spread. For example, if melanoma on your leg has spread to lymph nodes in your groin, the surgeon would remove the affected lymph nodes in that region. This is a more extensive surgery than a sentinel lymph node biopsy and requires careful planning and recovery time^[3].

The goal of surgery is to remove all visible cancer and achieve what doctors call “clear margins,” meaning no cancer cells are detected at the edges of the removed tissue when examined under a microscope. However, even when surgery appears to have removed all the cancer, microscopic cells may remain elsewhere in the body, which is why additional treatments are often recommended^[10].

Recovery from lymph node dissection can take several weeks. Possible side effects include swelling in the limb where lymph nodes were removed, a condition called lymphedema. This occurs because the lymphatic system’s ability to drain fluid from that area has been disrupted. Your healthcare team can teach you ways to manage and reduce this swelling. Other potential complications include infection, fluid collection at the surgical site, and reduced range of motion, though these can often be managed with appropriate care and physical therapy^[3].

Treatment After Surgery: Adjuvant Therapy

After surgical removal of stage III melanoma, doctors often recommend additional treatment called adjuvant therapy. The word “adjuvant” means “helping” or “assisting.” These treatments work by targeting any remaining microscopic cancer cells that surgery couldn’t remove—cells that are too small to detect with scans but could potentially cause the cancer to return or spread in the future^[10].

Adjuvant therapy for stage III melanoma has evolved dramatically in recent years. Patients with this stage of melanoma carry a high risk of recurrence, ranging from approximately 40% to 90% within five years after surgery alone, depending on the specific substage and characteristics of the tumor. The introduction of newer therapies has significantly improved outcomes, reducing the chance of cancer coming back and, in some cases, improving overall survival^[10].

Immunotherapy

Immunotherapy is a type of treatment that helps your own immune system recognize and attack cancer cells. Unlike chemotherapy, which directly kills rapidly dividing cells, immunotherapy works by removing the “brakes” that prevent your immune system from attacking cancer. Several immunotherapy drugs have been approved for use after surgery in stage III melanoma^[10].

One approved immunotherapy is pembrolizumab, which belongs to a class of drugs called PD-1 inhibitors. PD-1 is a protein on immune cells that acts like a checkpoint, preventing the immune system from attacking normal tissues. Cancer cells can exploit this checkpoint to hide from immune detection. Pembrolizumab blocks this checkpoint, allowing immune cells to recognize and destroy cancer cells. This drug is typically given as an intravenous infusion every three weeks^[9].

Clinical trial results for pembrolizumab showed significant benefits. In a study involving over 1,000 patients with stage III melanoma who had surgery to remove their cancer and affected lymph nodes, those who received pembrolizumab were much less likely to have their melanoma return compared to those who received placebo. At the time of follow-up, 74% of people treated with pembrolizumab had not experienced recurrence, compared to 57% in the placebo group. Additionally, more patients who received pembrolizumab were alive without their cancer spreading to other parts of the body^[9].

Another immunotherapy option is nivolumab, which also works as a PD-1 inhibitor with a similar mechanism to pembrolizumab. These medications have transformed treatment for stage III melanoma, offering patients a powerful tool to prevent recurrence^[10].

A different type of immunotherapy called ipilimumab targets a checkpoint protein called CTLA-4. This drug was among the first immunotherapies proven to improve survival in melanoma patients when used after surgery at a dose of 10 milligrams per kilogram. However, at this higher dose, ipilimumab caused more frequent and severe side effects compared to newer immunotherapies^[10].

Side effects from immunotherapy occur because activating the immune system can sometimes cause it to attack normal tissues in the body, leading to inflammation. Common side effects include fatigue, skin rash, diarrhea, and changes in liver or thyroid function. More serious but less common effects can involve the lungs, intestines, or other organs. Most side effects can be managed with medications, and some patients may need to temporarily stop or permanently discontinue immunotherapy if serious side effects develop. Your healthcare team will monitor you closely and provide guidance on recognizing and reporting symptoms^[10].

Targeted Therapy

Targeted therapy is treatment that attacks specific molecular changes in cancer cells. For melanoma, one of the most important molecular targets is a mutation in a gene called BRAF. Approximately 40-50% of melanomas have a BRAF mutation, which causes cells to grow and divide uncontrollably. If your melanoma has a BRAF mutation (most commonly BRAF V600E or V600K), you may be eligible for targeted therapy^[10].

Targeted therapy for BRAF-mutated melanoma typically combines two types of drugs: a BRAF inhibitor and a MEK inhibitor. BRAF and MEK are proteins involved in a signaling pathway that controls cell growth. By blocking both proteins simultaneously, the combination therapy is more effective and causes fewer side effects than using a BRAF inhibitor alone. Approved combinations for adjuvant treatment of stage III melanoma include dabrafenib plus trametinib^[10].

These targeted drugs are taken as pills, typically daily. Clinical trials have shown that patients with BRAF-mutated stage III melanoma who receive adjuvant targeted therapy after surgery have significantly lower rates of recurrence compared to those who received placebo. The treatment is usually continued for one year^[10].

Side effects of targeted therapy differ from those of immunotherapy. Common side effects include fever, chills, fatigue, joint pain, rash, nausea, and diarrhea. Some patients develop skin changes such as thickening or wart-like growths. Most side effects are manageable with dose adjustments or supportive medications. Less commonly, targeted therapy can affect heart function or cause vision changes, so your doctor will monitor these aspects during treatment^[10].

It’s important to note that targeted therapy only works if your melanoma has the specific BRAF mutation. Testing your tumor tissue for this mutation is essential before starting targeted therapy. If your melanoma doesn’t have a BRAF mutation, immunotherapy remains the standard approach^[10].

High-Dose Interferon

Before the development of modern immunotherapies and targeted therapies, high-dose interferon alfa was used as adjuvant treatment for stage III melanoma. Interferon is a protein naturally produced by the immune system to fight infections and cancer. When given at high doses, it can help prevent melanoma recurrence, and some studies showed improvements in overall survival compared to observation alone^[10].

However, high-dose interferon requires intensive administration—intravenous infusions five days per week for four weeks, followed by injections under the skin three times weekly for 48 additional weeks. The treatment causes significant side effects including flu-like symptoms, fatigue, depression, and effects on liver and blood counts. Because newer therapies are generally more effective and better tolerated, high-dose interferon is now rarely used, though it may still be considered in specific situations^[10].

Innovative Approaches Being Studied in Clinical Trials

Clinical trials are research studies that test new treatments or new ways of using existing treatments. For stage III melanoma, numerous clinical trials are exploring approaches that may further improve outcomes beyond current standard treatments. Participating in a clinical trial can give you access to cutting-edge therapies before they become widely available^[10].

Neoadjuvant Therapy

One innovative approach being studied is neoadjuvant therapy—giving immunotherapy or targeted therapy before surgery rather than after. This strategy has several potential advantages. Treatment before surgery may shrink tumors, making them easier to remove. It also allows the immune system to be activated while the tumor is still in place, potentially leading to a stronger immune response. Researchers can also examine the surgically removed tissue to see how well the treatment worked, which provides valuable information about prognosis^[10].

Early results from neoadjuvant trials have been promising, with high rates of complete or major pathological response—meaning little to no viable cancer remaining in the removed tissue. Some trials are comparing neoadjuvant therapy followed by surgery to the standard approach of surgery followed by adjuvant therapy. If neoadjuvant therapy proves more effective or allows some patients to avoid or reduce the extent of surgery, it could become a new standard of care^[10].

Combination Immunotherapies

Researchers are investigating whether combining different types of immunotherapy might be more effective than single agents. For example, trials are testing combinations of PD-1 inhibitors (like pembrolizumab or nivolumab) with CTLA-4 inhibitors (like ipilimumab) in the adjuvant setting. This approach is already used for advanced melanoma, where combinations have shown higher response rates, though with increased side effects^[10].

The challenge with combination immunotherapy is balancing effectiveness against toxicity. When multiple immune checkpoints are blocked simultaneously, the risk of immune-related side effects increases. Clinical trials carefully monitor participants to determine optimal dosing schedules and combinations that maximize benefit while minimizing harm. Some studies are exploring lower doses of ipilimumab combined with standard doses of PD-1 inhibitors to achieve this balance^[10].

Novel Immunotherapy Agents

Beyond PD-1 and CTLA-4 inhibitors, scientists are developing immunotherapies that target other immune checkpoints or activate the immune system through different mechanisms. One area of interest is LAG-3 inhibitors, which block another checkpoint protein that can suppress immune responses. Combinations of LAG-3 inhibitors with PD-1 inhibitors are being tested in advanced melanoma and may eventually be studied in the adjuvant setting if they prove effective^[10].

Another promising approach is tumor-infiltrating lymphocyte (TIL) therapy. This technique involves removing immune cells from a patient’s tumor, growing them in large numbers in the laboratory, and then infusing them back into the patient. TIL therapy is complex and resource-intensive, but early results in advanced melanoma have been encouraging. Researchers are exploring whether this approach might benefit patients with high-risk stage III disease^[10].

Cancer Vaccines

Cancer vaccines are designed to train the immune system to recognize and attack specific proteins found on cancer cells. Unlike preventive vaccines that protect against infections, cancer treatment vaccines are given after cancer has already developed. Several melanoma vaccine candidates are in various stages of clinical trial testing^[10].

Some vaccines target specific tumor antigens—proteins that are present on melanoma cells but not on normal cells. When the vaccine is administered, it stimulates an immune response against cells carrying these proteins. Other vaccines are personalized, created specifically for each patient based on the unique mutations in their tumor. These personalized neoantigen vaccines are custom-designed to target proteins resulting from mutations specific to an individual’s cancer^[10].

Early-phase clinical trials of personalized vaccines combined with immunotherapy have shown promising results, with some patients experiencing strong immune responses and remaining disease-free. However, these approaches are still experimental, expensive, and time-consuming to produce. Larger trials are needed to confirm their effectiveness before they can become standard treatment options.

Oncolytic Virus Therapy

Oncolytic viruses are genetically modified viruses that selectively infect and kill cancer cells while leaving normal cells unharmed. One such virus, called talimogene laherparepvec (T-VEC), is already approved for treating melanoma that has spread to the skin or lymph nodes and cannot be completely removed by surgery. T-VEC is injected directly into tumors, where it replicates within cancer cells, causing them to burst. As the cells die, they release tumor antigens that can stimulate an immune response^[10].

Researchers are studying whether oncolytic virus therapy combined with immunotherapy might be effective as adjuvant treatment for high-risk stage III melanoma. By stimulating both direct tumor cell killing and immune activation, this combination approach might reduce recurrence rates. Clinical trials are ongoing to evaluate safety and effectiveness in this setting.

Predictive Biomarkers

Not all patients respond equally to immunotherapy or targeted therapy. Scientists are working to identify biomarkers—measurable characteristics of tumors or blood that can predict which patients are most likely to benefit from specific treatments. For example, researchers are studying whether the level of PD-L1 expression on tumor cells, the number of mutations in the tumor, or the composition of immune cells within the tumor can help guide treatment decisions^[10].

Other studies are examining circulating tumor DNA (ctDNA) in blood samples. ctDNA consists of tiny fragments of tumor DNA that can be detected in the bloodstream. The presence of ctDNA after surgery may indicate residual disease that increases recurrence risk. Clinical trials are testing whether patients with detectable ctDNA might benefit from more intensive therapy, while those without it might be able to avoid treatment or use shorter durations^[10].

Understanding Clinical Trial Phases

Clinical trials progress through phases, each designed to answer specific questions about a new treatment. Understanding these phases can help you evaluate whether a trial might be appropriate for you^[10].

Phase I trials are the first studies of a new treatment in humans. They involve small numbers of patients and focus primarily on safety—determining the appropriate dose, identifying side effects, and observing how the body processes the drug. Phase I trials may include patients with various types or stages of cancer^[10].

Phase II trials enroll more patients and begin to evaluate whether the treatment works against specific types of cancer. These studies continue to monitor safety while gathering preliminary evidence of effectiveness. Phase II trials typically involve patients with the specific cancer type being studied^[10].

Phase III trials are large studies that compare the new treatment to the current standard treatment. These trials are randomized, meaning participants are assigned by chance to receive either the new treatment or the standard treatment. Phase III trials provide the strongest evidence about whether a new treatment is better than existing options. If successful, results from Phase III trials can lead to approval of new treatments by regulatory agencies^[10].

Participating in a clinical trial is voluntary, and you can withdraw at any time. Before enrolling, you’ll receive detailed information about the study, including potential risks and benefits. You’ll have opportunities to ask questions and discuss the trial with your healthcare team. Clinical trials have strict eligibility criteria to ensure participant safety and study validity, so not everyone will qualify for every trial^[10].

When Surgery Is Not Possible

In some cases, stage III melanoma cannot be completely removed by surgery. This might happen if the cancer has spread to multiple lymph node areas, involves critical structures that can’t be safely removed, or if the patient’s overall health makes surgery too risky. When surgery isn’t an option, treatment focuses on controlling the cancer and maintaining quality of life^[3].

For unresectable stage III melanoma, the same types of treatments used for more advanced disease may be recommended. Immunotherapy with PD-1 inhibitors or combination immunotherapy can shrink tumors and control disease progression. Targeted therapy is an option for patients whose tumors have BRAF mutations. In some cases, these systemic treatments may shrink the cancer enough that surgery becomes possible later^[3].

Radiation therapy may also play a role in treating stage III melanoma. High-energy radiation can be directed at tumors to shrink them or control symptoms. Radiation is sometimes used after lymph node surgery if there’s concern about microscopic cancer remaining in the area. While melanoma was historically considered resistant to radiation, modern techniques using higher doses per treatment have shown effectiveness^[3].

For melanoma deposits in the skin or lymph nodes that can be accessed directly, injection of oncolytic virus therapy (T-VEC) may be considered. This local treatment can cause injected tumors to shrink and sometimes triggers immune responses that affect distant tumors as well^[3].

Most Common Treatment Methods

• Surgery
  • Wide local excision to remove the melanoma with surrounding healthy tissue margins
  • Sentinel lymph node biopsy to check if cancer has spread to the first draining lymph nodes
  • Lymph node dissection to remove groups of affected lymph nodes
• Immunotherapy
  • PD-1 inhibitors (pembrolizumab, nivolumab) given intravenously to help the immune system attack cancer cells
  • CTLA-4 inhibitors (ipilimumab) that remove immune system brakes, though used less commonly due to side effects
  • Combination immunotherapy being studied in clinical trials
  • Oncolytic virus therapy (T-VEC) injected directly into accessible tumors
• Targeted Therapy
  • BRAF inhibitors combined with MEK inhibitors (dabrafenib plus trametinib) for tumors with BRAF mutations
  • Oral medications taken daily, typically for one year after surgery
• Radiation Therapy
  • High-energy radiation directed at tumor sites to control disease or manage symptoms
  • Sometimes used after lymph node surgery to reduce recurrence risk
• Clinical Trial Therapies
  • Neoadjuvant therapy given before surgery to shrink tumors
  • Novel immunotherapy combinations targeting multiple immune checkpoints
  • Personalized cancer vaccines custom-designed based on tumor mutations
  • Tumor-infiltrating lymphocyte (TIL) therapy using patient’s own immune cells

Duration and Monitoring of Treatment

The duration of adjuvant therapy for stage III melanoma varies depending on the specific treatment used. Standard adjuvant immunotherapy with pembrolizumab is typically given for one year—a total of approximately 17 infusions every three weeks. Adjuvant targeted therapy with BRAF and MEK inhibitors is also usually continued for one year. These treatment durations are based on clinical trial evidence showing maximum benefit with acceptable side effects^[9].

During treatment, you’ll have regular appointments to monitor for side effects and assess how well you’re tolerating therapy. Blood tests will check organ function, particularly liver and thyroid function during immunotherapy. Your healthcare team will ask about symptoms and perform physical examinations. If significant side effects occur, treatment may be temporarily held, the dose may be adjusted, or medications may be given to manage the side effects. In some cases, treatment must be permanently discontinued if severe side effects develop^[10].

After completing adjuvant therapy, ongoing surveillance is crucial. The risk of recurrence is highest in the first few years after treatment, so you’ll have frequent follow-up appointments. Initially, you may see your doctor every three to six months. These visits typically include physical examination, blood tests, and imaging studies such as CT scans to check for any signs of cancer recurrence. As time passes without recurrence, the interval between appointments gradually lengthens^[15].

Self-examination is also important. You should regularly check your skin for new or changing spots and examine the area where your melanoma was removed for any changes. Swollen lymph nodes, persistent lumps under the skin, or new symptoms should be reported to your doctor promptly. Many recurrences are first detected by patients themselves, so being vigilant about changes in your body is valuable^[15].

Quality of Life Considerations

Living with and being treated for stage III melanoma affects many aspects of life beyond the physical disease. The emotional impact of a cancer diagnosis can be profound, bringing feelings of anxiety, fear, uncertainty, and stress. These reactions are completely normal, and acknowledging them is an important part of coping^[13].

Many people find it helpful to focus on aspects of their health and life that remain under their control. This might include maintaining good nutrition, staying physically active within your abilities, getting adequate rest, managing stress through relaxation techniques or counseling, and staying connected with supportive family and friends. Even small positive actions can help create a sense of agency during a time when much may feel uncertain^[13].

Your healthcare team can connect you with support services including counseling, support groups where you can meet others going through similar experiences, and practical assistance with challenges such as transportation to appointments or financial concerns. Don’t hesitate to ask for help—these resources exist specifically to support people dealing with cancer and its treatment^[15].

Maintaining open communication with your healthcare team is essential. Bring a list of questions to appointments, consider bringing a family member or friend to help remember information discussed, and don’t be afraid to ask for clarification if something isn’t clear. Understanding your treatment plan and what to expect can reduce anxiety and help you feel more in control^[16].

Some people find it helpful to keep a journal tracking symptoms, side effects, questions for doctors, and how they’re feeling emotionally. This can help identify patterns, facilitate communication with your healthcare team, and provide a sense of the journey you’re traveling. Others prefer to maintain as much normalcy as possible, continuing work and regular activities as much as their health permits. There’s no single “right way” to cope—what matters is finding approaches that work for you^[13].

Looking Ahead

Treatment for stage III melanoma has been transformed over the past decade. Where once surgery alone was the only option, patients now have access to powerful therapies that significantly reduce the risk of recurrence and extend survival. Immunotherapy and targeted therapy have proven effective in large clinical trials, and ongoing research continues to refine treatment approaches and develop new options^[10].

Clinical trials remain active worldwide, investigating questions such as optimal treatment duration, whether certain patients can safely receive shorter or less intensive therapy, whether neoadjuvant approaches are superior to adjuvant treatment, and whether biomarkers can better personalize treatment decisions. Participation in research not only potentially benefits the individual participant but also contributes to advancing knowledge that will help future patients^[10].

While a diagnosis of stage III melanoma is serious, many people treated today will be cured of their disease. Even for those who experience recurrence, additional effective treatments are available. The landscape of melanoma care continues to improve, offering hope and increasingly positive outcomes for patients facing this disease^[16].