Malignant Melanoma Stage II

Stage II melanoma is a localized skin cancer that has grown deeper into the skin layers but has not yet spread to lymph nodes or other parts of the body. Understanding the characteristics of this stage and available treatment options is essential for making informed decisions about your care.

Table of contents

• What is Stage II Melanoma
• Substages of Stage II Melanoma
• How Staging is Determined
• Treatment for Stage II Melanoma
• Tests on Lymph Nodes
• Risk of Cancer Returning

What is Stage II Melanoma

In Stage II melanoma, the cancer cells are present in both the first layer of skin—called the epidermis (the very outer layer of skin)—and the second layer, known as the dermis (the thicker layer beneath)^[1][2]. Stage II melanoma extends beyond the epidermis into the thicker dermis layer of the skin^[1].

Stage II melanoma is considered local melanoma, which means the cancer is only in the skin and there is no sign that it has spread to nearby lymph nodes or other parts of the body^[1][2]. This group also includes Stage 0 and Stage I melanoma^[1].

Stage II melanoma is thicker than Stage I melanoma and is slightly more likely to spread to other areas of the body. However, there is still no evidence that it has spread to the lymph tissues, lymph nodes, or body organs at this stage^[1].

Substages of Stage II Melanoma

Stage II melanoma is divided into three subgroups based on two key factors: the depth (thickness) of the tumor and whether ulceration (broken skin over the melanoma) is present^[1][2]. Ulceration means the skin covering the melanoma was bleeding or looked crusty, and it can also be identified under the microscope^[6].

Stage IIA Melanoma: The melanoma tumor is more than 1.0 millimeter and less than 2.0 millimeters thick (up to the size of a new crayon point) with ulceration, or it is more than 2.0 millimeters and less than 4.0 millimeters thick without ulceration^[1][2].

Stage IIB Melanoma: The melanoma tumor is more than 2.0 millimeters and less than 4.0 millimeters thick with ulceration, or it is more than 4.0 millimeters thick without ulceration^[1][2].

Stage IIC Melanoma: The melanoma tumor is more than 4.0 millimeters thick with ulceration^[1][2]. This is the most worrisome substage within Stage II melanoma^[6].

The depth of the tumor refers to how deep into the skin the melanoma has grown. This is different from some other kinds of cancers where the main concern is how big the tumor is. A melanoma on the skin can look quite large with a splotchy appearance but in reality may not be a deep lesion. The deeper it goes into the skin, the more serious it is^[6].

How Staging is Determined

Melanoma staging is based on the American Joint Committee on Cancer (AJCC) staging system. This system assigns a stage based on tumor-node-metastasis (TNM) scores as well as additional factors that help predict outcomes. The goal is that melanomas of the same stage will have similar characteristics, treatment options, and outcomes^[1].

To diagnose melanoma, your doctor removes the abnormal area and a small area of surrounding skin. This is called an excision biopsy. A specialist doctor called a pathologist looks at the biopsy under a microscope. If there are melanoma cells, they will work out the stage of the cancer. You may have some other tests and scans to help with this^[2].

Doctors also use another staging system for melanoma called the TNM staging system. It stands for Tumor, Node, Metastasis. T describes the size of the tumor, N describes whether there are any cancer cells in the lymph nodes, and M describes whether the cancer has spread to a different part of the body. The TNM staging system describes the cancer in detail, while the number staging system puts these details together to give an overall stage^[2].

Treatment for Stage II Melanoma

Surgery is the main treatment for Stage II melanoma skin cancer^[2]. Stage II melanoma is treated by removing the tumor surgically^[1].

You usually have an operation to remove a larger area of skin around where the melanoma was. This is called a wide local excision. Doctors do this to remove any melanoma cells that might be in the surrounding skin. Wide local excision is a minor surgery that usually cures local melanoma^[1][2].

If you have a stage IIB or IIC melanoma, your doctor may recommend you have an immunotherapy drug called pembrolizumab (Keytruda) after surgery. This is to help stop the melanoma from coming back. Doctors call this adjuvant treatment^[2]. Another immunotherapy drug, nivolumab, has also been studied for this purpose^[10].

Treatment also depends on where the melanoma is located and your general health and level of fitness^[2].

Tests on Lymph Nodes

Your doctor will usually recommend a test to see if there are cancer cells in the lymph nodes near the melanoma. This is called a sentinel lymph node biopsy (SLNB). Your doctor removes the first lymph node or nodes that the melanoma could have spread to. You have a sentinel lymph node biopsy at the same time as a wide local excision^[2].

If you don’t have a sentinel lymph node biopsy, your doctor might ask you to have regular ultrasound scans of the lymph nodes. Doctors call this surveillance^[2].

If your doctor can feel that your lymph nodes near the melanoma are swollen (enlarged), they will take a sample of fluid or tissue to check for cancer cells. This is called a lymph node biopsy. You may have an ultrasound scan first, or you may have an ultrasound scan while you are having the biopsy to help guide the needle to the abnormal area^[2].

If your doctor finds cancer cells in the lymph nodes near the melanoma, the stage changes to stage III^[2].

Risk of Cancer Returning

Even if you’ve had surgery to remove melanoma, there is a chance melanoma can return or spread. When melanoma returns, it’s called recurrence. Your doctor may recommend treatment after surgery that may help prevent cancer from coming back or spreading^[13].

Results from a study reviewing medical charts of patients with stage IIB or IIC melanoma who were recommended to “watch and wait” after surgery showed concerning rates of recurrence. For patients with stage IIB melanoma, 37% of people (140 out of 375) had their cancer return after surgery, and 50% of those people (70 out of 140) had their cancer spread to other parts of the body after surgery. For patients with stage IIC melanoma, 43% of people (83 out of 192) had their cancer return after surgery, and 58% of those people (48 out of 83) had their cancer spread to other parts of the body after surgery^[13].

It’s important to talk with your doctors to understand your options, including treatment after surgery^[13].

Patients with stage IIB and IIC melanoma are considered to have high-risk localized disease. In some cases, they demonstrate worse recurrence-free and overall survival than patients with stage IIIA and even IIIB disease^[10].