Stage 4 melanoma means the cancer has spread beyond the skin and nearby lymph nodes to distant parts of the body. It is the most advanced stage of melanoma, and the five-year relative survival rate is about 34%, according to National Cancer Institute data from 2016 to 2022. That number has improved dramatically in recent years thanks to newer treatments, particularly immunotherapy and targeted drugs that didn’t exist a decade ago.
Where Stage 4 Melanoma Spreads
Melanoma can metastasize to virtually any organ, but certain sites are more common. Doctors classify stage 4 into subcategories based on where the cancer has traveled:
- Skin, soft tissue, or distant lymph nodes (M1a): The cancer has spread to skin or muscle in a different part of the body from the original tumor, or to lymph nodes far from the original site.
- Lungs (M1b): Metastases are found in the lungs, with or without skin or soft tissue involvement.
- Other internal organs (M1c): The cancer has reached organs like the liver, bones, or intestines.
- Brain or spinal cord (M1d): Metastases are found in the central nervous system, which generally carries the most serious prognosis.
These subcategories matter because they influence both prognosis and treatment decisions. A person with a single skin metastasis faces a different situation than someone with multiple brain lesions, even though both are technically stage 4.
How LDH Levels Affect the Outlook
Within each subcategory, doctors also check a blood marker called LDH (lactate dehydrogenase). LDH is an enzyme that rises when there’s widespread tissue damage, often from tumor growth in the liver, lungs, or other organs. It serves as an indirect measure of how much cancer is in the body. Elevated LDH at the time of diagnosis is linked to shorter survival, worse treatment response, and faster disease progression. Each M subcategory gets an additional designation of (0) for normal LDH or (1) for elevated LDH, which helps oncologists estimate how aggressive the disease is likely to be.
Symptoms of Advanced Melanoma
The symptoms of stage 4 melanoma depend entirely on where the cancer has spread. Some people notice hard, tender nodules under the skin, which are subcutaneous metastases. Lung metastases can cause a persistent cough or shortness of breath. Liver involvement may bring pain in the upper right abdomen, nausea, or jaundice. Brain metastases often present as headaches, seizures, vision changes, or difficulty with balance and coordination.
Beyond organ-specific symptoms, many people with stage 4 melanoma experience constitutional symptoms: unexplained weight loss, fatigue, and loss of appetite. These reflect the body’s systemic response to widespread cancer and can appear before imaging confirms where the disease has gone.
Immunotherapy: The Primary Treatment
Immunotherapy has transformed the treatment of stage 4 melanoma. These drugs work by releasing the brakes on the immune system, allowing it to recognize and attack cancer cells it was previously ignoring.
The standard first-line approach for most patients is a combination of two checkpoint inhibitors. One well-established combination pairs nivolumab (which blocks PD-1, a protein cancer uses to hide from the immune system) with ipilimumab (which blocks CTLA-4, a separate immune brake). This combination is particularly effective for melanoma that has spread to the brain, where treatment options were historically very limited.
A newer combination pairs nivolumab with relatlimab, which targets a third checkpoint protein called LAG-3. In clinical trials, this combination produced similar progression-free survival to the nivolumab-ipilimumab combination, around 10 months, but with significantly fewer serious side effects. Less than 20% of patients on the newer combination reported severe side effects, compared with nearly 60% on the older one. This makes it an important option for people who may not tolerate the more intense regimen.
Immunotherapy doesn’t work for everyone, but when it does work, the responses can be remarkably durable. Some patients remain in remission for years after completing treatment.
Targeted Therapy for BRAF Mutations
About half of all melanomas carry a mutation in a gene called BRAF, most commonly the V600E variant. This mutation acts like a stuck accelerator, telling cancer cells to grow nonstop. For these patients, targeted therapy is another option.
Treatment uses two drugs together: a BRAF inhibitor to block the faulty gene directly, and a MEK inhibitor to block a related growth signal downstream. The combination shrinks tumors in the majority of people with BRAF-mutant melanoma and works more effectively than either drug alone. These drugs tend to produce faster responses than immunotherapy, which makes them useful when the cancer is growing rapidly and there’s pressure to shrink tumors quickly. The tradeoff is that resistance typically develops over time, and most patients eventually need to switch to or add immunotherapy.
Treating Brain Metastases
Melanoma has a particular tendency to spread to the brain, and brain metastases are one of the most challenging aspects of stage 4 disease. For years, treatment was limited to surgical removal of accessible tumors followed by whole-brain radiation, or whole-brain radiation alone. Neither approach offered strong long-term control.
Focused radiation (radiosurgery) has changed this. Using precisely targeted beams, doctors can treat individual brain tumors with high-dose radiation in a single session, sparing the surrounding healthy brain tissue. Research from the Congress of Neurological Surgeons found that radiosurgery without whole-brain radiation can be a reasonable primary approach for eligible patients, since adding whole-brain radiation did not significantly improve survival or disease control in the brain. More than half of patients were able to stop or avoid steroids after radiosurgery, which is important because steroids can interfere with immunotherapy.
Immunotherapy also plays a growing role in brain metastasis treatment. Although it was once assumed these drugs couldn’t cross the blood-brain barrier effectively, studies have shown regression of brain lesions with immunotherapy. When given after focused radiation, immunotherapy appears to reduce the chance of new brain metastases forming.
TIL Therapy: A Newer Option
In February 2024, the FDA approved a treatment called lifileucel for patients with stage 4 melanoma who have already tried other treatments. This approach, known as TIL (tumor-infiltrating lymphocyte) therapy, works differently from standard immunotherapy. Doctors remove a sample of the patient’s tumor, isolate the immune cells that had already infiltrated it, grow billions of copies of those cells in a lab, and then infuse them back into the patient. Because these immune cells were already trying to fight the cancer, they can be more precisely targeted than the broader immune activation from checkpoint inhibitors. The treatment requires a hospital stay and a preparatory regimen to make room for the new cells, but it offers a meaningful option for patients whose cancer has progressed through other therapies.
How Survival Rates Have Changed
The 34% five-year survival rate for distant melanoma reflects a dramatic improvement from the pre-immunotherapy era, when that number was closer to 5 to 10%. The SEER data covering 2016 to 2022 captures a period when checkpoint inhibitors and targeted therapies were becoming standard care, and survival rates continue to trend upward as newer combinations and second-line options become available.
Individual prognosis varies widely based on where the cancer has spread, how many metastases are present, LDH levels, whether the tumor carries a BRAF mutation, and how well the cancer responds to initial treatment. Some patients with limited metastatic disease achieve complete responses and remain cancer-free for years. Others with widespread disease, particularly involving the brain or liver with elevated LDH, face a more difficult path. The subcategory of stage 4, not just the stage itself, shapes what to expect.