Malignant Melanoma is the deadliest form of skin cancer, with over 5,000 people in Canada being diagnosed each year. Roughly 900 people per year die from Melanoma. Starting in the pigment-producing cells, known as melanocytes, these cells begin to grow out of control and often appear brown or black because of this. Some Melanomas however, have no colour at all, called Amelanotic Melanoma. Melanoma can develop at any age, with it being the 4th most common form of cancer in 15-29 year olds. Males with fair skin are shown in studies to die more frequently than any other group. AN estimated 90% of Melanoma cases are directly linked to excessive UV exposure and sunburns.
Like other non-Melanoma skin cancers, Melanomas usually develop in UV exposed areas. However, they can also develop in areas where the skin has never been exposed to UV (Finger nail beds, behind the eye, underneath the foot or between the toes to name a few). According to the Canadian Skin Cancer Foundation, the most common areas for a Melanoma to develop is on the back or the legs. 50% of Melanomas develop in an existing mole, while the other 50% develop as a new lesion.
Malignant Melanoma is commonly described based on the A, B, C, D, and E’s:
A – Asymmetry – The lesion is not perfectly round. One side does not look like the other side.
B – borders – The outside edges of the lesion are irregular, blurry or jagged in appearance. They do not look like a distinct line.
C – colour – There is colour variation in the lesion. It can have black, brown, red and white areas of colour and typically contain more than one colour.
D – diameter – Melanoma’s grow, sometimes quite quickly. They are generally greater than 6mm in diameter.
E – evolution – The Melanoma will change over time. It can become bigger, larger, darker and may even become itchy or bleed.
A tip when trying to detect a Melanoma – one of these things is not like the others! Generally, a Melanoma will be very distinct from any other moles you may have. It may look, feel or change differently than your other moles. Those are signs it needs to be checked by your Dermatologist!
The Ugly Duckling is another warning sign of melanoma. This recognition strategy is based on the concept that most normal moles on your body resemble one another, while melanomas stand out like ugly ducklings in comparison. This highlights the importance of not just checking for irregularities, but also comparing any suspicious spot to surrounding moles to determine whether it looks different from its neighbors. These ugly duckling lesions or outlier lesions can be larger, smaller, lighter or darker, compared to surrounding moles. Also, isolated lesions without any surrounding moles for comparison are considered ugly ducklings.
It takes only one blistering sunburn to double a person’s chances of developing melanoma
Melanoma is one of the most common types of cancer for youth between the ages of 15-29
Life-time risk for melanoma is now 1 in 63 versus 1 in 1500 in the 1930s
In North America, one person dies from melanoma every hour
The leading cause of melanoma is overexposure to ultraviolet (UV) radiation from the sun or artificial sources (tanning beds, sunlamps)
Early exposure to tanning beds can increase a person’s chance of developing melanoma by up to 75%
Once you have had a biopsy that confirms a Melanoma, a second surgical excision will be required to ensure adequate removal of tissue with appropriately sized margins. Before this is done however, there are several factors that need to be considered first. The pathologist will classify the type of Melanoma and then depending on the type, will further stage the Melanoma and give it a Breslow depth (depth of the Melanoma from the surface of the skin to the deepest part of the tumour) and Clark’s Level (how deep the Melanoma has gone in the skin). These factors are used to give information about the outlook of the Melanoma for the patient.
1. Superficial Spreading Melanoma
This type of Melanoma appears in the upper layers of the skin and spreads outwards. It accounts for 70% of Melanomas diagnosed.
2. Nodular Melanoma
This type of Melanoma is more dangerous as it grows quickly and deeply into the skin. It typically appears on areas of the skin that have not been exposed to the sun and have a raised area that is usually very dark or sometimes red.
3. Lentigo Maligna Melanoma
This type of Melanoma is directly caused by excessive sun exposure. Found commonly in order people, it generally appears as a large flat dark spot with areas of brown and black.
4. Acral Lentiginous Melanoma
This Melanoma is most found in people with darker skin tones or Asian decent. They appear on the palms of hands, soles of feet or underneath fingernails or toenails.
Based on the thickness and other features of the tumour, stages provide information to help guide the treatment, prognosis, and recurrence risk, as well as if further tests need to be completed.
Stage 0: The tumour is limited to the upper layers of the skin and has not spread (Melanoma in-situ). Surgical excision is the only treatment required. Prognosis is excellent.
Stage 1: Considered to be an early Melanoma. Depending on severity (based on Breslow depth and Clark’s level), a Sentinel Lymph Node Biopsy may be indicated. Treatment also includes surgical re-excision, which can be done at the same time as the Sentinel Lymph Node Biopsy.
Stage 2: The Melanoma is more advanced and goes deeper into the skin. A sentinel lymph node biopsy is recommended. There is a moderate risk of recurrence or spread to another area of the body after surgical excision because of the tumour depth.
Stage 3: The Melanoma has spread to nearby lymph nodes. These will be removed during treatment.
Stage 4: This is the most advanced stage of Melanoma. The Melanoma has spread to another part of the body – usually the lungs, liver, brain or abdomen. This situation is uncommon.
Stages 3 & 4 require post-surgical management to prevent the recurrence or spread of the Melanoma. The following treatment options are available and may be combined:
To learn about a Sentinel Lymph Node Biopsy and it's importance, click the link below.
Once the type of Melanoma is determined, it is then given a Breslow depth. This is the most important determining factor for the prognosis of a Melanoma. The deeper the Melanoma is found to be, the more likely it has spread to other areas and the higher likelihood it will recur even once removed.
Melanomas that are found to be >1mm thick do not tend to spread. Treatment for these Melanomas are surgical removal with a specific margin skin. No further treatment or testing is required.
If the Breslow index is <1mm, a Sentinel Lymph Node Biopsy is suggested to test to determine if the Melanoma has spread to nearby lymph nodes. The results of this test help determine the stage of Melanoma and what treatment is required. Some further tests that may be required are bloodwork, a CT scan or a PET scan.
1. Ulceration – this refers to the breakdown of the skin on the surface of the Melanoma. Melanomas with ulceration are more serious and typically have a higher tendency to spread therefore are staged higher than Melanomas without ulceration.
2. Mitotic Rate – this measures the frequency of cell division within the Melanoma. Higher mitotic rates are associated with more rapidly dividing cells and therefore larger lesions, with greater potential for metastasis and poorer prognosis. Mitotic rate is thought to be the second most important factor (behind Breslow thickness) in determining prognosis, with a higher rate being predictive of a poorer prognosis. This value is used to stage very thin melanomas (<1mm).
3. Satellites: Satellite lesions (also called micro satellites) are areas of tumor/melanoma located more than 0.05 mm, but less than 2cm, from the primary lesion. Satellites are described as being present or absent. These are also reflected in the staging.
4. In-Transit Metastases: Similar to satellite lesions, however these areas are more than 2cm from the primary lesion without being beyond local lymph drainage (called the lymph node basin). These are also reflected in the staging.
This is a surgery used to determine if the Melanoma has spread to one or more lymph nodes. A sentinel lymph node is the first node in a chain that the Melanoma has most likely spread to. The surgery includes an injection of radioactive dye at the site of the Melanoma. The dye will then trace to the primary draining node. This node is removed and tested for the presence of Melanoma. If the node is negative, the likelihood the Melanoma has spread within the body is very unlikely. If the node is positive, all of the lymph nodes in that region are removed. A positive lymph node biopsy does not change the prognosis of the Melanoma. It is only used to assist the diagnosis.
Stage 0 to Stage 1 (low-risk)
Melanomas that are caught early enough (only in the upper layers of skin and show no evidence of spread) are typically treated by surgical excision only. These are excised by the surgeon with a safety margin around the area, usually 5mm-1cm wide, depending on the thickness and depth of the melanoma. This tissue is then sent off for evaluation to ensure all tissue margins are clear of any cancer cells and that no more surgical intervention is required. Depending on the location and other circumstances, the Mohs procedure may be used to clear the melanoma. If the melanoma is >0.8mm in thickness or has other characteristics that make it higher risk to spread, a sentinel lymph node biopsy may also be indicated. In some situations, the surgical removal and sentinel lymph node biopsy can be done at the same time.
Stage 2 (intermediate high-risk melanomas)
Because the risk of spreading to lymph nodes is higher with a stage 2 melanoma, it is often recommended that the patient, in additional to surgical excision, has a sentinel lymph node biopsy to check and make sure the melanoma hasn’t spread. If melanoma is found in any of the lymph nodes, after surgical excision, it may be recommended that additional therapies be had to help reduce the risk of the melanoma coming back (ie. Radiation, immunotherapy).
Stage 3 and stage 4 (advanced melanomas)
Melanomas become difficult to treat once they have spread past the original tumor to lymph nodes and/or organs. Newer immune-based therapies that have been developed in recent years are showing promising effects with stage 3 and stage 4 melanomas.
Patients with stage 3 melanomas now have the option available for adjuvant therapies after the surgical removal. These help the effectiveness of the surgery by possibly preventing or delaying the recurrence of the melanoma and improving the overall survival rate.
For patients with stage 4 melanomas, after the surgical removal, patients are numerous options that have high success rates. Even if one therapy does not work, the patient still has the option to try other therapies. Working to reduce the size of tumours and slowing the disease progression, these therapies can help extend the life expectancy by months to years to even potentially a cure.
Immunotherapies: Using medicines that stimulate the immune system to destroy cancer cells has lead to great strides being made in the ability to treat patients with advanced melanomas. Immunotherapies help by boosting the patient’s immune system by using a synthetic version of immune proteins to stop the release of cancer-causing cells.
Chemotherapy: Because of new advancements with immunotherapies and targeted therapies, chemotherapy is seldomly used now in the treatment of melanoma. It is typically used when these other therapies fail to work. Chemotherapy work systemically through the body to stop tumour growth by killing cancer cells and stop them from multiplying.
Radiation: Radiation is only used to treat melanoma if it has spread to the brain or other distant areas to help reduce tumour size and pain. It is sometimes used at the site of surgical removal to ensure all cancer cells have been destroyed. Radiation uses high-intensity x-ray beams to penetrate and keep tumour cells from growing. If a melanoma has a high risk of recurrence, radiation is used after surgery to reduce the risk of recurrence. If a melanoma has recurred at the primary site or lymph nodes, doctors will sometimes use radiation to reduce or eliminate the tumor and help prevent distant spread. If a melanoma has already spread, radiation can be used to help other therapies be more effective.
The Melanoma Network of Canada (MNC) provides support services, information, and programs for individuals whose lives have been changed by melanoma and skin cancer. MNC is the leading national voice for patients in Canada, advocating for drug therapies, for early detection and improved treatment access. They work diligently to prevent more Canadians from developing skin cancer through public awareness and sun safety.
The Save Your Skin Foundation is a national patient-led not-for-profit group dedicated to the fight against non-melanoma cancers, melanoma and ocular melanoma nationwide education, advocacy, and awareness initiatives. Save Your Skin Foundation is committed to playing an active role in reducing the incidence of skin cancer in Canada, and ensuring equal, timely, and affordable access to best care and compassionate support for all Canadians living with skin cancer, wherever they are in in their journey.