Melanoma Staging

Melanoma is a serious type of skin cancer that begins in the skin’s pigment-producing cells (melanocytes). Often, the first noticeable sign is an unusual or evolving mole, typically a dark, irregularly shaped skin spot with jagged borders. Key risk factors include fair skin, excessive sun exposure, tanning bed use and a family history of melanoma.

When detected early, melanoma can often be treated effectively and even cured. However, because the cancer tends to spread quickly, understanding its stage is critical to developing the right treatment plan.

What is melanoma staging and why is it so important?

Melanoma staging is the process used by physicians to measure the extent of the cancer and determine whether it has spread beyond the skin. This important information can be used to guide treatment decisions, help predict the outcome and monitor for recurrence.

The stage of melanoma is influenced by several factors, including:

• The size and thickness of the tumor
• The depth of cancer invasion into the skin
• The presence of ulceration (skin breakdown)
• Any spread to nearby lymph nodes or distant organs (metastasis)

Accurate staging can help the physician develop an individualized treatment plan to address the patient’s specific cancer.

How is melanoma staged?

When staging melanoma, the physician may consider the results of several diagnostic tests, including:

• Skin biopsy – A small sample of tumor tissue will be microscopically examined by a pathologist, who can confirm the presence of melanoma and measure the thickness of the lesion.
• Sentinel lymph node biopsy – This procedure can help the physician determine if melanoma cells have spread to nearby lymph nodes. During the biopsy, a special dye and radioactive tracer will be injected near the tumor site to identify the “sentinel” lymph node—the first node to which the cancer is most likely to spread. The node will then be surgically removed and examined under a microscope.
• Imaging scans – Computed tomography (CT) or magnetic resonance imaging (MRI) scans can help the physician check for cancer spread to internal organs.
• Blood work – Certain blood tests can detect markers that may suggest advanced cancer.

Based on the overall findings, the physician will assign a stage to the melanoma.

What are the different stages of melanoma?

Melanoma stages range from 0 to 4. Some stages have subgroups indicated by letters A through D. A higher number and letter indicate a more extensive tumor.

Stage 0 (melanoma in situ)

At stage 0, abnormal cells remain confined to the outermost layer of skin (epidermis). The precancerous skin lesion may resemble a mole or freckle with an irregular shape, ragged border or mixture of colors, such as red, brown and tan. Additionally, the lesion may repeatedly shrink and grow, change color, bleed or itch. To help ensure a prompt diagnosis and treatment, it is important to discuss any unusual skin changes with a physician.

How is stage 0 melanoma treated?

The main treatment approach for stage 0 melanoma is surgery, which usually involves a wide local excision to remove the lesion and a slim margin of surrounding healthy skin. Alternatively, if the lesion is located in a cosmetically sensitive area, such as the face, the physician might suggest Moh’s micrographic surgery. The excised tissue will be sent to a laboratory for microscopic examination by a pathologist. If abnormal cells are detected in the margin, the physician may recommend a second, wider excision of the affected area.

Stage 1 (early-stage melanoma)

At stage 1, melanoma cells have spread beyond the epidermis and grown into the second layer of skin (dermis). However, the tumor remains confined to the area of the body where it originated.

Stage 1 melanoma may be further classified as:

• Stage 1A – The tumor is less than 1 millimeter thick with no ulceration.
• Stage 1B – The tumor is up to 2 millimeters thick with or without ulceration.

How is stage 1 melanoma treated?

Usually, stage 1 melanoma treatment involves a wide local excision to remove the tumor along with a small margin of surrounding healthy tissue. The width of the margin can vary depending on the location and thickness of the melanoma. Often, no further treatment is needed.

If the melanoma is stage 1B or has other characteristics that make it more likely to spread, the physician may also order a sentinel lymph node biopsy to determine whether any cancer cells have spread to the sentinel node. If the sentinel node is clear, no further treatment may be needed, although close follow-up will remain important.

If melanoma cells are found in the sentinel node, the melanoma will be reclassified as stage 3, and the physician may recommend a lymph node dissection to remove all nodes located near the tumor site. Alternatively, the physician may suggest a watch-and-wait approach, which may involve periodic imaging scans to monitor the lymph nodes for signs of cancer.

Stage 2 (intermediate-stage melanoma)

At stage 2, the melanoma extends deeper into the dermis but has not spread to nearby lymph nodes or metastasized to distant organs or tissues.

Stage 2 melanoma may be further classified as:

• Stage 2A – The tumor is 1.01 to 2.0 millimeters thick with ulceration, or 2.01 to 4.0 millimeters thick without ulceration.
• Stage 2B – The tumor is 2.01 to 4.0 millimeters thick with ulceration, or greater than 4.0 millimeters thick without ulceration.
• Stage 2C – The tumor is greater than 4.0 millimeters thick with ulceration.

How is stage 2 melanoma treated?

Stage 2 melanoma is usually treated with surgical removal along with a sentinel lymph node biopsy, which is recommended for all stage 2 tumors regardless of size. A high-risk patient may also receive immunotherapy or targeted therapy (if the melanoma has a BRAF gene mutation) to help reduce the risk of recurrence.

Stage 3 (regional-spread melanoma)

At stage 3, the cancer has spread to one or more regional lymph nodes or developed an in-transit or satellite metastasis. This occurs when cancer cells enter the lymphatic system and spread from the original tumor to a new skin or subcutaneous lesion located between the primary tumor and the regional lymph nodes. There is no evidence of cancer spread to distant organs or tissues.

Stage 3 melanoma may be further classified as:

• Stage 3A – The melanoma has spread to up to three nearby lymph nodes, but the lymph nodes are not visibly enlarged (the spread is detected under a microscope). The primary tumor may or may not be ulcerated.
• Stage 3B – The melanoma has spread to nearby lymph nodes and the affected nodes are visibly enlarged (clinically detectable), the primary tumor is ulcerated or small deposits of melanoma cells are found in nearby skin or lymphatic channels, indicating in-transit or satellite metastasis.
• Stage 3C – The melanoma has spread to four or more lymph nodes or to matted (joined together) nodes. The primary tumor may be ulcerated, and in-transit or satellite metastases may be present.
• Stage 3D – The melanoma has spread to four or more lymph nodes or to matted nodes, the primary tumor is ulcerated and in-transit or satellite metastases are present.

How is stage 3 melanoma treated?

Treatment options for stage 3 melanoma may include:

• Surgery, including tumor removal, sentinel lymph node biopsy and possibly lymph node dissection
• Immunotherapy
• Targeted therapy
• Radiation therapy (in select cases)

Because the risk of melanoma recurrence is high at stage 3, close monitoring and follow-up imaging will be essential.

Stage 4 (metastatic melanoma)

At stage 4, the most advanced form of melanoma, the cancer has metastasized beyond the original tumor and nearby lymph nodes. Common metastasis sites include the lungs, liver, brain, bones, and distant lymph nodes and skin areas. The primary tumor can vary in size and depth.

Depending on the area of the body affected, the patient may experience symptoms such as:

• Hardened lumps under the skin
• Persistent fatigue
• Weight loss or poor appetite
• Difficulty breathing
• Bone pain
• Neurological changes, such as headaches and seizures

How is stage 4 melanoma treated?

Treatment for stage 4 melanoma may involve:

• Immunotherapy checkpoint inhibitors, such as pembrolizumab or nivolumab
• Targeted therapy for a tumor with a BRAF or MEK mutation
• Radiation therapy or surgery for certain tumors
• Clinical trials to access new, advanced melanoma treatments

What questions should I ask my physician about my melanoma stage?

Being diagnosed with melanoma can be overwhelming, and you will understandably want clear, reliable answers. Asking thoughtful questions during your consultations can help you understand your diagnosis, explore your treatment options and prepare for what comes next. Maintaining an open dialogue with your physician can empower you to take a more active role in your treatment and recovery.

Questions to ask about your melanoma diagnosis and treatment

When discussing your initial diagnosis and treatment plan with your physician, these questions can help you understand the extent of your melanoma and the therapies available to you:

• What stage is my melanoma, and what does that mean for me?
• Has my cancer spread to lymph nodes or other organs?
• What melanoma treatment options are best for my stage?
• Am I a candidate for immunotherapy, targeted therapy or clinical trials?
• What are the possible side effects of these treatments?
• How will you monitor my cancer during and after treatment?

Questions to ask about your life after melanoma treatment

Once your melanoma treatment is complete, you will likely want to know what you can expect in the months and years that follow. These questions can guide conversations with your physician about your long-term health and recurrence prevention:

• How often will I need to have imaging tests and follow-up visits?
• What signs or symptoms should I watch for that might suggest recurrence?
• What lifestyle changes can help reduce the risk of my melanoma coming back?
• Should my family members be screened for melanoma or other skin cancers?
• What resources are available for emotional support or survivorship care?

Remember: no question is too small when it comes to your health. Your physician is there to listen, support you and guide you every step of the way.

Benefit from world-class care at Moffitt Cancer Center

The Cutaneous Oncology Program at Moffitt is home to a multispecialty team of skin cancer experts. These professionals are highly experienced in the diagnosis and staging of melanoma and take a comprehensive approach to individualized treatment. Members of Moffitt’s skin cancer team—including surgical oncologists, dermatologists, pathologists, radiologists, plastic surgeons, medical oncologists, dermatopathologists and other specialists—meet weekly in a tumor board to review complex cases, helping to ensure that every patient receives the best possible care.

If you have questions about melanoma staging, you can request an appointment with a specialist at Moffitt by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.

References

American Cancer Society: Melanoma Skin Cancer Stages
American Cancer Society: What is Melanoma Skin Cancer?
Healthline: What Do the Symptoms of Stage 4 Melanoma Look Like?
WebMD: Metastatic Melanoma