Melanoma The Cancerous Mole
What is Melanoma?
Melanoma or a “cancerous mole” is a less common type of skin cancer arising from the skin’s pigment cells. Melanocytes produce a pigment called melanin that gives the skin its colour and protects it from sun damage. Darker skin has more melanin and more protection. Melanocytes often cluster together and form moles (nevi). Most moles are benign, but some may go on to become malignant melanomas.
Melanoma is one of the most dangerous skin cancers but good treatments are available and many patients make an excellent and full recovery. It is important to examine your skin regularly – the moles that you have on your body are yours and you need to know them well. Any new mole that appears or if any of the existing moles change – a visit to your doctor or a dermatologist would be warranted.
Are there different types of melanoma?
YES – There are several types of melanoma. These types are distinguished by their pattern of growth (whether they grow outward or downward), location and prognosis.
There are 4 different types of melanoma:
Superficial Spreading MelanomaThis is the most common variant of melanoma accounting for 2/3 of all melanomas. It often presents as a dark brown or black flat stain on the skin or appears as a change from a pre-existing mole.
Nodular MelanomaThis type of melanoma is usually not related to a pre-existing mole. It generally presents as a smooth bump (papule or nodule) that is often blue-black in colour. This type of melanoma can sometimes grow rapidly and spread to the lymph nodes.
Acral-Lentiginous MelanomaThis type of melanoma occurs on the palms of the hand, on the soles of the feet or under nail beds, and can grow and spread quickly. It is the most common melanoma in dark-skinned individuals. It is important that any mole on the hands and feet be assessed, as these are not usual locations for moles.
Lentigo Maligna MelanomaThis form of melanoma is mostly found on the most sun-damaged skin such as on the face of older individuals.
What Causes Melanoma?
Sunlight is the main environmental agent that causes melanoma. However, the exact wavelengths of sunlight that cause melanoma are unknown. Research has shown that people with certain risk factors are more likely than others to develop melanoma. A risk factor is anything that increases a person’s chance of developing a disease. Still, many get this disease with no known risk factors. As more research continues, we are finding more and more information as to the more detailed causes of melanoma.
The following are established risk factors for melanoma:
Dysplastic molesDysplastic moles (nevi) are common, and many people have a few of these abnormal moles. The risk of melanoma is greatest for people who have a large number of dysplastic nevi. The risk is especially high for people with a family history of both dysplastic nevi and melanoma.
Many ordinary moles (more than 50)Having many moles increases the risk of developing melanoma.
Fair skinMelanoma occurs more frequently in people who have fair skin that burns or freckles easily (these people also usually have red or blond hair and blue eyes) than in people with dark skin. Caucasians get melanoma far more often than do black people, probably because light skin is more easily damaged by the sun.
Personal history of melanoma or other skin cancersPeople who have been treated for melanoma have a high risk of a second melanoma. Some people develop more than two melanomas. People who had one or more of the common skin cancers (basal cell carcinoma or squamous cell carcinoma ) are at increased risk of melanoma.
Family history of melanomaMelanoma sometimes runs in families. Having two or more close relatives who have had this disease is a risk factor. About 10 percent of all patients with melanoma have a family member with this disease. When melanoma runs in a family, a doctor should check all family members regularly.
Weakened immune systemPeople whose immune system is weakened by certain cancers, by drugs given following organ transplantation, or by HIV are at increased risk of developing melanoma.
Severe, blistering sunburnsPeople who have had at least one severe, blistering sunburn as a child or teenager are at increased risk of melanoma. Because of this, doctors advise that parents protect children’s skin from the sun. Such protection may reduce the risk of melanoma later in life. Sunburns in adulthood are also a risk factor for melanoma.
Ultraviolet (UV) radiationExperts believe that much of the worldwide increase in melanoma is related to an increase in the amount of time people spend in the sun. This disease is also more common in people who live in areas that get large amounts of UV radiation from the sun. In the United States, for example, melanoma is more common in Texas than in Minnesota, where the sun is not as strong. UV radiation from the sun causes premature aging of the skin and skin damage that can lead to melanoma. Artificial sources of UV radiation, such as sunlamps and tanning booths, also can cause skin damage and increase the risk of melanoma. Doctors encourage people to limit their exposure to natural UV radiation and to avoid artificial sources.
What are some of the treatments for Melanoma?
Melanomas are highly curable if caught early and have not spread beyond the site where they developed.
Treatment decisions for melanoma are based on:
- Stage of the cancer
- Thickness of the cancer
- Location of the cancer
- Patient’s general health as well as personal situation
The Specific Treatments for Melanoma include the Following:
SurgeryThis is the primary standard treatment for localized melanoma. Additional (adjuvant) therapy may be given after surgery for high-risk melanomas to destroy any cancer cells that may have escaped from the primary site. Chemotherapy and radiation therapy are both adjuvant therapies for melanoma.
ChemotherapyThis reaches cells all over the body (systemic therapy) and destroys cancer cells that may have traveled from the primary melanoma site. Chemotherapy is usually given in advanced melanoma.
Radiation TherapyThis destroys cancer cells that may still be in the area after a melanoma is removed. It may be used for select cases of melanoma.
Biological Therapy (immunotherapy)This may be offered as adjuvant therapy for melanomas with higher risk of recurrence or regional lymph node metastasis. Nonspecific immunotherapy is used to stimulate the immune system as a whole. Specific immunotherapy targets the tumor selectively. The primary agent used in biological therapy is high dose interferon alpha.
It is important to know your own skin including your moles. If you notice any changes, please see your family doctor or a dermatologist.