Melanoma

What is a Melanoma:

Malignant melanoma, or simply “melanoma”(since there is no benign form of the disease) is not a typical skin cancer but rather a malignant (cancerous) mole. It may arise from a preexisting mole (viz. a junctional or compound nevus) or from a single cell (the melanocyte) in an area of previously appearing normal skin.

When a melanoma starts in the skin, it is called a cutaneous melanoma.

In men, melanoma is often found on the trunk (the area from the shoulders to the hips) or the head and neck. In women, melanoma often develops on the arms and legs. Melanoma may also occur in the eye (ocular melanoma or intraocular melanoma) and, rarely, in other areas where melanoctes are found, such as the digestive tract or meninges. When melanoma spreads (metastasis), cancer cells are also found in the lymph nodes and possibly also other parts of the body, such as the liver lungs, or brain. In these cases, the cancer cells are still melanoma cells, and the disease is called metastatic melanoma.

Risk Factors:

Unusual moles.

changes in size, shape, or color

has irregular edges or borders

is more than 1 color

is asymmetrical (if the mole is divided in half, the 2 halves are different in size or shape)

oozes, bleeds, or is ulcerated

exposure to natural sunlight.

exposure to artificial ultraviolet light (tanning booth).

family or personal history of melanoma.

being white and older than 20 years.

red or blond hair.

white or light-colored skin and freckles.

blue eyes.

Diagnosis:

It is important to detect melanoma as early as possible. In patients with a suspicious-appearing mole, the diagnosis of melanoma is established by a biopsy. To perform a biopsy, local anesthetic is injected under the skin to numb the area. The entire mole, or a small sample of the mole, is removed and examined in the laboratory by a pathologist to determine if the mole is cancerous.

Tumor Microstaging:

Once the diagnosis of melanoma has been established, the tumor is carefully examined to determine how deeply it has grown into the skin. This degree of skin invasion is known as the “tumor microstage.” The microstage has tremendous bearing upon type of treatment, prognosis, and survival. It is most often described in terms of Clark’s level and Breslow thickness.

Clark’s level:

The skin has essentially five anatomic layers, or levels, from the outermost epidermis (level) to the underlying fat (level V). Clark’s level refers to deepest portion of the skin invaded by tumor, level I being preinvasive, level II thinly invasive, levels III-IV moderately invasive, and level V deeply invasive. Since overall skin thickness varies considerably throughout the body (e.g. eyelid skin versus heel skin), the level of invasion is more qualitative than quantitative.

Breslow thickness:

This is the most commonly used measurement. This measurement, in millimeters (mm), is the actual thickness of the melanoma which is a reflection of the depth of penetration of the tumor into the skin. Tumors less than 1mm thick (.1-.99mm) are considered lower risk; those 1.0-3.99 are intermediate risk, and 4.0mm or more are higher risk.

Most often both descriptors are used to define a melanoma (e.g. level III, 1.5mm depth).

Staging of the Melanoma:

The process used to find out whether cancer has spread within the skin or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the tumor and is important in planning the treatment.

The following tests and procedures may be used in the staging process

Wide local excision: A surgical procedure to remove the melanoma and some of the surrounding normal tissue.

Lymph node mapping and sentinel lymph node biopsy: A procedure in which a radioactive material and/or blue dye is injected near the tumor. The substance or dye flows through lymphatic sentinel node or nodes (the first lymph node or nodes where cancer cells are likely to spread). The surgeon removes only the nodes with the radioactive substance or dye. A pathologist examines the sentinel lymph nodes for cancer cells. If no cancer cells are detected, it may not be necessary to remove additional nodes.

Chest x-ray:

CT scan: Tests may be done of the chest, abdomen, and pelvis.

MRI:

PET scan:

Laboratory tests:

Treatment of Melanoma:

Wide Excision:

Biopsy alone is not a treatment for melanoma and in the absence of additional therapy is associated with unacceptably high rates of local recurrence. The surgical removal of additional surrounding skin is necessary to reduce the risk of tumor regrowth, and is called “wide-excision”.

The extent of additional skin removal, that is, the size of the wide excision, is influenced by a multitude of factors, including tumor microstage ( Clark’s level and Breslow thickness), presence of ulceration, tumor location and patient age.

In general and where anatomically possible, melanomas less than 1.0mm thick require at least 1cm margins of wide-excision, while tumors 1.0mm or more thick require removal of at least 2cm margins of normal-appearing surrounding skin.

Wide-excision may reduce local recurrence to 3% or less.

Lymph Node Treatment:

The presence of melanoma in adjacent lymph nodes is often an intermediate phase of disease, prior to disease spread to other parts of the body. Lymph nodes function as filters and trap germs as well as cancer cells. These “gatekeepers” form one of the body’s first lines of defense.

At the time of diagnosis of melanoma it is often difficult, if not impossible, to determine whether or not lymph node involvement has occurred since only a few cancer cells may have migrated to nearby lymph nodes. However, enlarged, firm lymph nodes virtually always contain melanoma and should be removed without biopsy. This is termed a “therapeutic lymph node dissection”; that is removal of abnormal lymph nodes.

Lymph nodes that appear normal on physical examination may or may not contain melanoma. Surgeons have recently discovered methods that may help determine whether or not small, normal appearing lymph does may contain melanoma cells, this is called “sentinel lymph node biopsy”.

This biopsy technique uses radioactive particles and/or blue dye injected into the previous melanoma biopsy site. This test often can determine which lymph node may be involved with tumor (i.e. sentinel lymph node), thereby limiting the number of lymph nodes removed and thereby significantly reducing unnecessary surgery.

If the sentinel lymph node does not contain tumor cells, additional lymph nodes are not removed. Alternately, if the sentinel lymph node contains melanoma it is presumed that other lymph nodes in the area may also be contaminated with melanoma cells; in which case all nearby lymph nodes are removed (therapeutic lymph node dissection).

Chemotherapy:

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). In treating melanoma, chemotherapy drugs may be given as a hyperthermic isolated limb perfusion. This technique sends anticancer drugs directly to the arm or leg in which the cancer is located. The flow of blood to and from the limb is temporarily stopped with a tourniquet, and a warm solution containing anticancer drugs is put directly into the blood of the limb. This allows the patient to receive a high dose of drug in the area where the cancer occurred.

The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Radiation Therapy:

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are place directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Biologic Therapy:

Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.

Chemoimmunotherapy:

Chemoimmunotherapy is the use of anticancer drugs combined with biologic therapy to boost the system to kill cancer cells.

Stages and Treatment of Melanoma:

Stage 0 :

In stage 0, melanoma is found only in the epidermis (outer layer of the

skin). This is called in situ.

Treatment:

• Removal of the tumor with a small amount of normal tissue (1cm).

Stage I:

Stage I is divided into IA and IB

Stage IA: the tumor is not more than 1mm thickness, with no ulceration in the epidermis and upper layer of the dermis.

Treatment:

• Removal of the tumor with a clear border of 1cm normal skin.

Stage IB: The tumor is not more then 1mm in thickness, with ulceration or 1-2mm thick and no ulceration.

Treatment:

• Removal of the tumor with a clear border of 1-2cm of normal skin. A sentinel lymph node biopsy to see if there is any spread of tumor to the lymph nodes. If tumor is present than a formal lymph node dissection.

Stage II:

Stage II is divided into stages IIA, IIB, and IIC

Stage IIA: tumor is either 1-2mm thick, with ulceration or

2-4mm thick and no ulceration

Stage IIB: tumor is either 2-4mm thick with ulceration or

more the 4mm thick and no ulcers

Stage IIC: tumor is more the 4mm thick and ulceration

Treatment for Stage II:

• Removal of tumor with clear border of 2cm of normal skin. Also a sentinel lymph node biopsy to see if there is any spread of tumor to the lymph nodes. If tumor is present than a formal lymph node dissection. If lymph nodes are felt to be enlarged before surgery then formal lymph node dissection without the need for a sentinel lymph node biopsy.

• Following surgery an oncologist may recommend high-dose immunotherapy or a clinical trial with chemoimmunotherapy.

Stage III:

This tumor may be any thickness, with or without ulceration and has lymph node spread.

Treatment:

• Surgery to remove the tumor with 2cm of clear margins and formal lymph node dissection. Complete workup to determine if there is any metastatic disease that would make this Stage IV disease.
• Following surgery an oncologist may recommend high-dose immunotherapy or a clinical trial with chemoimmunotherapy.
• Other clinical trials possible with hyperthermic isolated limb perfusion using chemotherapy and immunotherapy, or clinical trials with immunotherapy and radiation therapy.

Stage IV:

This tumor may be any thickness, with or without ulceration, may have spread to lymph nodes and has spread to other organs in the body.

Treatment:

• Surgery or radiation therapy as palliative therapy to relieve symptoms and improve quality of life.
• Chemotherapy and/or immunotherapy.

Recurrent Melanoma:

Recurrent melanoma is cancer that has recurred (come back) after it has been treated. The tumor can come back in the original site or in other parts of the body, such as the lungs or liver.

Treatment:

• Possible surgery to remove the tumor.
• Possible radiation therapy as palliative therapy to Relieve symptoms and improve quality of life.
• Possible palliative treatment with immunotherapy
• Clinical trials with hyperthermic isolated limb perfusion if tumor localized to one extremity.
• Clinical trials with biologic and/or chemotherapy as palliative therapy to relieve symptoms and improve live.