Stage II melanoma is a form of skin cancer that has penetrated deeper into the skin layers but shows no signs of spreading to nearby lymph nodes or distant organs. Understanding this stage is crucial for patients and their families, as it represents a critical point where early intervention through surgery and, in some cases, additional therapy can make a significant difference in preventing the cancer from returning.

What is Stage II Melanoma?

Stage II melanoma is a type of skin cancer where cancer cells exist in both the outermost layer of skin, called the epidermis, and have grown into the deeper second layer known as the dermis. This stage is considered “local melanoma” because there is no evidence that the cancer has traveled to lymph nodes, lymph tissues, or other organs in the body. The melanoma at this stage is thicker than Stage I and carries a slightly higher risk of spreading to other parts of the body in the future.^[1]

The classification of Stage II melanoma depends heavily on two key factors: the thickness of the tumor and whether the skin covering the melanoma appears broken under a microscope. The thickness refers to how deeply the melanoma has grown into the skin layers, not necessarily how large it appears on the surface. A melanoma might look quite large and spread out across the skin but actually be shallow, or it could be small in appearance but have grown deeply into the tissue. This depth measurement is critical because deeper melanomas have a greater chance of spreading.^[6]

Ulceration is the second important factor in staging. This term describes whether the skin covering the melanoma is intact or broken. When examined visually, an ulcerated melanoma often appears crusty or may have been bleeding. Under the microscope, doctors can see changes in the cells and skin tissue that indicate ulceration. The presence of ulceration makes the melanoma more concerning, as it typically indicates a more aggressive cancer.^[6]

Substages of Stage II Melanoma

Stage II melanoma is divided into three substages, each reflecting different levels of concern and risk. These substages help doctors understand how likely the melanoma is to return or spread, which in turn guides treatment decisions.^[1]

Stage IIA melanoma includes tumors that are more than 1.0 millimeter but less than 2.0 millimeters thick with ulceration, roughly the size of a new crayon point, or tumors that are 2.0 to 4.0 millimeters thick without ulceration. This substage is considered the least worrisome within Stage II.^[1]

Stage IIB melanoma describes tumors that are 2.0 to 4.0 millimeters thick with ulceration, or those that are more than 4.0 millimeters thick without ulceration. At this substage, doctors begin to have increased concern about the melanoma’s potential to spread.^[1]

Stage IIC melanoma represents the most worrisome category within Stage II. These are melanomas that measure more than 4.0 millimeters in thickness and show ulceration. This combination of significant depth and broken skin makes these tumors particularly concerning for potential recurrence.^[1]

How Stage II Melanoma is Diagnosed

The diagnosis of Stage II melanoma begins with an excision biopsy, where a doctor removes the abnormal area of skin along with a small border of surrounding normal skin. This tissue sample is then examined under a microscope by a specialist doctor called a pathologist. The pathologist looks for melanoma cells and, if present, measures the thickness of the tumor and checks for ulceration to determine the exact stage.^[2]

After the initial diagnosis, doctors typically recommend additional testing to ensure the melanoma has not spread to nearby lymph nodes. The most common test is a sentinel lymph node biopsy (SLNB), which identifies and removes the first lymph node or nodes that the melanoma would most likely spread to first. This procedure is usually performed at the same time as a wider excision surgery. If a patient does not have an SLNB, doctors may recommend regular ultrasound scans of the lymph nodes, a practice called surveillance.^[2]

If doctors can feel swollen lymph nodes near the melanoma during a physical examination, they will take a sample of fluid or tissue from those nodes to check for cancer cells. This may involve an ultrasound-guided biopsy to ensure the needle reaches the correct area. If cancer cells are found in the lymph nodes, the stage changes to Stage III melanoma, which requires different treatment approaches.^[2]

Causes of Melanoma

The primary cause of melanoma is overexposure to ultraviolet (UV) radiation, particularly from sunlight. Statistics indicate that approximately 86% of melanomas are caused by solar UV rays. When UV radiation hits the skin, it can damage the DNA inside skin cells, causing changes to specific genes that control how cells grow and divide. When this DNA damage occurs in melanocytes, the cells that produce skin pigment, and those damaged cells begin reproducing uncontrollably, melanoma can develop.^[7]

Sunburns, especially those occurring during childhood and young adulthood, represent a major risk factor for developing melanoma later in life. The skin damage from these burns accumulates over time. Additionally, UV radiation from tanning beds significantly increases the risk of melanoma. The artificial UV light in tanning beds can cause the same type of DNA damage as natural sunlight, leading to cancerous changes in skin cells.^[7]

Risk Factors for Melanoma

Several factors increase a person’s likelihood of developing melanoma. Fair skin, blonde or red hair, and blue eyes make individuals more susceptible to melanoma because they have less melanin, the pigment that provides some natural protection against UV radiation. People with these characteristics tend to burn more easily in the sun and are at higher risk.^[7]

The number of moles on a person’s body can predict melanoma risk. While about 30% of melanomas develop from existing moles, the majority begin in normal skin. However, having many moles suggests that the skin may be more prone to developing melanoma. Individuals should pay careful attention to any new spots or changes in existing moles.^[7]

A personal or family history of melanoma significantly increases risk. Those who have had melanoma before face a higher chance of developing another melanoma in the future. Similarly, if close family members have had melanoma, this suggests a possible genetic predisposition that increases risk. Age also plays a role, as melanoma is one of the most common cancers in young people under 30, particularly in young women.^[7]

A weakened immune system, whether from medical conditions or medications that suppress immune function, can increase melanoma risk. The immune system normally helps identify and destroy abnormal cells, including cancer cells, so when it is compromised, the risk of various cancers, including melanoma, rises.

Symptoms and Signs of Melanoma

Recognizing the signs of melanoma is essential for early detection and treatment. The American Academy of Dermatology developed the “ABCDE” rule to help people identify suspicious spots on their skin. The “A” stands for asymmetry, meaning one half of the spot does not match the other half. The “B” represents border irregularity, where the edges are not smooth or even. The “C” indicates color variation, with the spot showing uneven coloring with shades of brown, black, gray, red, or white. The “D” refers to diameter, particularly spots larger than the tip of a pencil eraser (6.0 millimeters). Finally, the “E” stands for evolving, meaning the spot is new or has changed in size, shape, or color.^[7]

However, not all melanomas follow the ABCDE rule. Some may appear as sores that won’t heal, unusual bumps, or rashes. This is why it’s important to report any concerning skin changes to a doctor, even if they don’t fit the typical pattern. Another useful sign is the “ugly duckling” sign, where one mole looks noticeably different from all the others on a person’s body. Any mole that stands out as the odd one should be examined by a dermatologist.^[7]

Melanoma can appear in different forms, including moles, scaly patches, open sores, or raised bumps. While most melanomas are black or brown, some can be pink, red, purple, or even skin-colored, making them harder to identify. This variability in appearance makes regular skin checks and awareness of changes particularly important.^[7]

Prevention of Melanoma

Preventing melanoma focuses primarily on protecting skin from UV radiation. Wearing appropriate clothing in the sun is one of the most effective strategies. Close-weave cotton clothing, long sleeves, and long trousers provide physical barriers against UV rays. A hat with a wide brim is particularly important as it shades the face and neck, areas that receive significant sun exposure.^[18]

Sunscreen plays an important role in protection when used correctly. For individuals at higher risk, including those who have already had melanoma, doctors often recommend using a high sun protection factor (SPF) sunscreen, typically SPF 50, on all exposed skin. The sunscreen should protect against both UVA and UVB rays. UVB rays are stronger and cause sunburn, while UVA rays, though weaker, penetrate deeper into the skin. Both types contribute to skin cancer development.^[18]

To get the best protection from sunscreen, it should be applied 15 to 30 minutes before going outside, spread thickly and evenly over the skin, and allowed to dry. Regular reapplication is essential, especially after swimming or sweating. The sunscreen should be stored properly, out of direct sunlight and in a cool, dry place, to maintain its effectiveness.^[18]

Timing outdoor activities wisely can reduce UV exposure. In the UK, staying out of the sun between 11am and 3pm, when UV radiation is strongest, helps minimize risk. Sunglasses protect the eyes from UV damage, and tanning beds should never be used, as they deliver concentrated UV radiation that significantly increases melanoma risk.^[18]

Treatment Options for Stage II Melanoma

Surgery is the primary treatment for Stage II melanoma. The main surgical procedure is called a wide local excision, where doctors remove a larger area of skin around where the melanoma was originally found. This extended removal helps ensure that any melanoma cells that might have spread into the surrounding skin are also removed. The width of the excision depends on how thick the melanoma was. This surgery is typically considered minor and, in many cases, cures local melanomas.^[1]

For patients with Stage IIB or IIC melanoma, doctors may recommend additional treatment after surgery to help prevent the cancer from returning. This is called adjuvant therapy. The immunotherapy drug pembrolizumab (also known by the brand name Keytruda) has been approved for this purpose. Clinical trials showed that patients who received pembrolizumab after surgery were more likely to remain cancer-free compared to those who did not receive this additional treatment.^[2]

In a major clinical trial involving patients with Stage IIB or IIC melanoma, 487 people received pembrolizumab while 489 received placebo after their surgery. At the time of follow-up, 89% of those who received pembrolizumab had not experienced cancer recurrence, compared to 83% of those who received placebo. Additionally, 87% of the pembrolizumab group did not have their cancer spread to other parts of the body, compared to 81% in the placebo group.^[13]

The decision to pursue adjuvant therapy involves weighing the benefits of reducing recurrence risk against potential side effects of treatment. Patients with Stage IIA melanoma are not currently recommended for adjuvant therapy with the same medications, though they should discuss their individual situation with their oncologist. Every patient’s case is unique, and treatment decisions should be made collaboratively with the healthcare team, considering personal health status, risk tolerance, and treatment goals.^[2]

The Role of the Healthcare Team

Managing Stage II melanoma typically involves several different healthcare professionals working together. A dermatologist specializes in skin conditions and is often the first doctor to diagnose melanoma. They may also monitor patients after treatment to check for any signs of cancer returning.^[13]

A surgeon performs the operations needed to remove the melanoma. After surgery, the surgeon may refer the patient to an oncologist for further evaluation and treatment planning. An oncologist is a doctor who specializes in cancer and cancer treatment. Working alongside the dermatologist and surgeon, the oncologist helps develop the complete treatment plan, including determining whether adjuvant therapy after surgery is necessary.^[13]

Patients who have not been referred to an oncologist should ask their surgeon or dermatologist about whether a consultation would be beneficial. Having a comprehensive care team ensures that all aspects of treatment, from surgery through follow-up care, are properly coordinated and that patients receive the most appropriate care for their specific situation.

Follow-Up Care and Skin Monitoring

After treatment for Stage II melanoma, ongoing monitoring is essential. People who have had melanoma face a higher than average risk of developing another melanoma in the future. This makes regular skin checks and protection from sun exposure particularly important throughout life.^[18]

Patients should become familiar with what their skin normally looks like and remain alert to any changes. Any new spots, changes in existing moles, or changes where the original melanoma was located should prompt a visit to the doctor. While it’s important to stay vigilant, patients should try not to become overly anxious, as most changes are not cancer.^[18]

Regular follow-up appointments with the healthcare team are scheduled based on the specific stage and characteristics of the melanoma. These appointments typically include physical examinations of the skin and lymph nodes. The frequency of follow-up visits may decrease over time if no problems are detected, but maintaining a relationship with the healthcare team remains important for long-term monitoring.^[19]

How Stage II Melanoma Affects the Body

Stage II melanoma develops when changes occur in melanocytes, the specialized cells in the skin that produce melanin, the pigment that gives skin its color. When UV radiation or other factors damage the DNA in these cells, they can begin to grow and divide uncontrollably, forming a tumor. In Stage II melanoma, this tumor has grown through the epidermis and into the deeper dermis layer of the skin.^[1]

The thickness of the melanoma indicates how far it has penetrated into the skin layers. Thinner melanomas remain closer to the surface, while thicker ones extend deeper into the tissue. The depth matters because the deeper layers of skin contain blood vessels and lymphatic vessels. If melanoma cells reach these vessels, they can potentially travel to other parts of the body, though in Stage II melanoma, there is no evidence this has happened yet.^[6]

Ulceration occurs when the melanoma tumor grows so aggressively that it breaks through the skin’s protective outer layer. This breakdown of the normal skin structure reflects the tumor’s aggressive behavior and indicates a higher risk that cancer cells might spread. The presence of ulceration, combined with tumor thickness, helps doctors predict how the melanoma is likely to behave and what treatment approach is most appropriate.^[6]