Melanoma and skin cancer
Besides melanoma, there are two principal types of skin tumors: a tumor made up of cells resembling the middle layer of the epidermis (squamous cell carcinoma) and basal cell carcinoma, comprised of cells at the deepest layer of the epidermis. These tumors differ in their source cells, in their clinical behavior and in the treatment for them. Melanoma is the most violent and dangerous type of cancerous growths that develop in skin tissue. These tumors originate in the melanin-producing cells called melanocytes, which are responsible for producing skin pigment. Melanocytes serve to protect the skin from ultra-violet radiation from the sun. UV radiation constitutes the highest risk factor for the development of melanoma in these cells. Although the main function of melanocytes is expressed between the layers of skin, the origin of these cells during fetal development is actually in the central nervous system. These cells roam from the area of the brain throughout the body to the various sections of skin in adults. Therefore, the cancerous growths in the melanoma group are liable to develop in tissue nearly anywhere in the body.
Risk factors for the development of melanoma:
The main risk factors for the development of melanoma include:
Genetic predisposition: this predisposition closely relates to the color of a person’s skin. Light-skinned people, and mainly “red-heads,” are at the highest risk of developing melanoma, particularly when they are outside of their “natural habitat” – in other words, families that migrated from regions with low direct sunlight, such as Europe, to regions with intense sunlight, such as the Middle East – and the State of Israel, which is home to many of these families, has a relatively high level of risk and incidence of melanoma.
Exposure to sunlight: constitutes a principal risk factor for the development of melanoma. It is well known that prolonged exposure to sunlight during childhood raises the risk for the development of melanoma during later years, and melanoma is the main reason why it is extremely important to avoid exposing children to sunlight without adequate/full protection using sun screen with a particularly high SPF (sun-protection factor) – which is extremely important for fair-skinned people, but is also important for people with dark skin.
Genetic predisposition: besides a familial tendency for light skin, there are genetic mutations that raise the degree of risk of developing melanoma, mutations that tend to be passed down in families, and which may be tested and identified early.
Since the disease is extremely violent, early detection is critical! Since, in most cases, the disease develops in the skin layers, you can conduct a periodic visual examination of moles and growths that you suspect might become melanoma. People at higher risk of contracting this disease: light-skinned people, people with a family history of the disease, or people who have a large number of benign melanocytes on their skin (beauty marks), should undergo routine examination by a skin doctor or plastic surgeon in order to detect melanoma as soon as possible at its earliest stages.
There are a number of “warning signs” of a benign growth developing into a cancerous tumor: if the growth grows from examination to examination, if it changes color, if it contains a number of different colors, if it changes shape, develops uneven borders – all these constitute warning signs of the possibility of the development of a malignant tumor that requires the performance of a biopsy and full removal of the growth in order to conduct a histological test.
Staging and prognosis:
Melanomas develop very violently and pose a very high risk that the disease will spread or metastasize, which is directly linked to the depth of their penetration of the skin layers. Therefore, the depth of the penetration constitutes a very important factor when diagnosing the disease and for deciding on surgical removal. Later follow ups and patient treatment decisions are considerably affected by the depth of penetration of the primary tumor. Furthermore, many times during surgery, adjacent lymph nodes that melanoma have a tendency to invade are removed. The number of affected glands also constitutes a factor that must be considered when deciding the patient’s treatment plan.
One of the unique characteristics of melanoma is the fact that they tend to activate the patient’s immune system. As a result, there are instances when the melanoma shrinks and even disappears naturally, as a result of the body’s immune system attacking the tumor cells. Although of course, one should not “count on” your body fighting the disease, this fact guided researchers and physicians to develop melanoma treatment directions. Directions include, inter alia, therapy that affects mainly the body’s immune system, such as interferon.
Treatment of melanoma:
Treatment of melanoma has advanced considerably in recent years. The majority of the treatment is based, primarily, on complete surgical excision of the primary tumor and of affected glands to the extent possible. Subsequently, the attending physician will decide on the use of additional drug treatments according to clinical criteria – beginning with drugs that affect the activity of the patient’s immune system, such as interferon, up to using chemotherapy drugs whose efficacy in treating this disease have been proven.
Today, tests can characterize the genetic profile of the specific tumor. Melanoma is one of the first tumors for which the process of genome sequencing has been completed. Today, we know the entire genetic sequence of melanoma – a sequence that helps researchers in their efforts to develop drugs having maximum impact on this disease. Characterizing the genetic profile enables physicians to consider prescribing drugs that they would not have normally considered in the past – a very important fact, particularly when treatments of an aggressive strain, such as melanoma, are being considered.