What is the melanoma

At least four hundred new cases are diagnosed each year in Greece. The frequency of the most aggressive skin cancer is estimated that has increased at 30% the last five-year period. At the same time, except the cases of melanoma, twenty thousands cases of skin cancers is estimated that are diagnosed each year in Greece (even if there are not kept officially epidemiologic files.)

What is the melanoma

Melanoma is a type of skin cancer and it begins in cells in the skin called melanocytes.   Melanocytes produce melanin, the pigment that gives skin its natural colour. When skin is exposed to the sun, melanocytes produce more pigment, causing the skin to tan, or darken. So, this pigment has the role to protect the skin from the harmful effect of ultraviolet radiation, which is considered to be the most carcinogenetic factor for the skin.
If the melanoma is not diagnosed and not removed in time, it acquires aggressive biological behaviour, it gives metastases in the internal nearby tissues and organs, and constitutes frequent cause of death.   Melanoma, the deadliest skin cancer, accounts for only 4% of skin cancers. This type of cancer often spreads to the lymph nodes and internal organs. While melanomas have a variety of physical appearances, they are most often pigmented lesions greater than 0.6 mm. they may show a range of colors and generally have an irregularly-shaped, asymmetrical border. Usually, they  have black colour, contrary to the other skin cancers that have rosy colour. The chance of developing it increases with age, but this disease affects people of all ages. It can occur on any skin surface. In men, melanoma is often found on the trunk (the area between the shoulders and the hips) or the head and neck, areas that is to say which are protected during wintry months and are exposed abruptly in intense solar report, as it happens at the beginning of summertime. In women, it often develops on the lower legs. It can however be developed at any point of the body or in the base of a mole, but also in healthy skin that does not even have in that point a mole, in points that are protected from the solar exposure, as is the scalp of head or the buttock. Exists also a form of melanoma, which is developed in the face of very old people, in the region of a pre existing spot, and which grows very slowly by the time. 

Usually the melanoma makes its appearance at the age of 40-45 years, but it can also appear in the age of the 30-40 years, and very seldom in the children's and adolescent age. In the half cases of melanoma in the children's age, melanoma appears in the base of giant moles.

What is skin cancer

Skin cancer is the most common form of human cancer.  The most common warning sign of skin cancer is a change in the appearance of the skin, such as a new growth or a sore that will not heal.  Skin cancers are slow-growing tumours which occur most commonly on areas of the body that are exposed to sun like the face and hands. Skin cancers are also known as skin neoplasia. The skin has two main layers:  the outer epidermis and the inner dermis. Skin cancer usually begins in the outer epidermis, which is mostly made up of flat, scalelike cells called squamous cells. Round cells called basal cells lie under the squamous cells in the epidermis. However, rarely it may also begin in the inner dermis in the sweat glands. (The dermis contains blood vessels, lymph vessels, hair follicles, and glands. Some of these glands produce sweat).  The term "skin cancer" refers to three different conditions. From the least to the most dangerous, they are: basal cell carcinoma (or basal cell carcinoma epithelioma), squamous cell carcinoma (the first stage of which is called actinic keratosis) and melanoma. The two most common forms of skin cancer are basal cell carcinoma and squamous cell carcinoma. Together, these two are also referred to as nonmelanoma skin cancer.

1. Basal cell carcinoma is by far the most common type of skin cancer, accounting for 80% of cases. These slow-growing tumors occur mostly on the face and rarely on the rest of the body. A raised, reddish, pearly nodule is the most common appearance of basal cell carcinoma, but it may also appear as a pink or red scar or area of irritated skin. Light-coloured skin, sun exposure, and age are all important factors in the development of basal cell carcinomas. People who have fair skin and are older have higher rates of basal cell carcinoma. About 20% of these skin cancers, however, occur in areas that are not sun-exposed, such as the chest, back, arms, legs, and scalp. The face, however, remains the most common location for basal cell lesions. Basal cell carcinomas metastasize very rarely; instead, they grow invasively into surrounding tissues and can cause localized tissue destruction. For that reason this type of cancer should be detected and removed at an early stage, otherwise it can cause considerable local damage.

2.  Sqaumous cell carcinoma is the second most common type of skin cancer, representing about 16% of all skin cancers. Squamous cell carcinoma is cancer that begins in the squamous cells, which are thin, flat cells that look like fish scales under the microscope.  Its appearance is similar to a chronic ulcerated area of the skin or a crusty or scaly skin lesion. Unlike basal cell carcinomas, squamous cell cancers metastasize to other parts of the body like the lymph nodes and internal organs, when they are not detected and removed at an early stage.
Light-colored skin and a history of sun exposure are even more important in predisposing to this kind of cancer than to basal cell carcinoma. Men are affected more often than women. Patterns of dress and hairstyle may play a role. Women, whose hair generally covers their ears, develop squamous cell carcinomas far less often in this location than do men. Squamous cell carcinomas can develop from precancerous spots, called actinic or solar keratoses. Actinic keratoses appear as rough, red bumps on the scalp, face, ears, and backs of the hands. They often appear against a background of mottled, sun-damaged skin. They can be quite sore and tender, out of proportion to their appearance.

Leading causes for melanoma


According to the researchers - dermatologist doctors, sun exposure is the leading cause for the 70% to 80% of melanoma cases, and people with fair skin and light eyes whose skin has a tendency to burn easily in the sun are most susceptible to the damaging effects of the sun's UV rays. . Other factors that contribute are:
• Genetic factors
• Weakened immune system
• Giant moles that exist from the birth
• Certain infrequent hereditary dermatitis.
The heredity: In a percentage of 10% of cases exists heredity, with the significance that coexist also other cases of melanoma in the same family. Apart from the familial background, genetic inclination usually exists in patients diagnosed with melanoma in young age under the 30 years, and in persons who are diagnosed with more the one melanoma. Even if that there exists a genetic test for the melanoma, which detects mutations of the only one gene that has been connected at the present moment - with the melanoma (gene CDKN2A or p16), its practical application in patients with melanoma is found under investigation. 

What are risk factors for melanoma?


No one knows the exact causes of melanoma. Doctors can seldom explain why one person gets melanoma and another does not.
However, 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 who do get this disease have no known risk factors.
Studies have found the following risk factors for melanoma:
  Ultraviolet (UV) radiation: Experts 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, and who spend  a lot of hours to the sun due to their type of work or hobby activities.

  Severe, blistering sunburns: People who have had at least one severe, blistering sunburn as a child or tennager are at increased risk of melanoma.

Fair skin: Melanoma 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. White people get melanoma far more often than do black people, probably because light skin is more easily damaged by the sun.

  Many (more than 50) ordinary moles: Having many moles increases the risk of developing melanoma.

Dysplastic nevi: Dysplastic nevi are more likely than ordinary moles to become cancerous. Dysplastic 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.

 Giant moles: Having giant moles increases the risk of developing melanoma.

Personal history of melanoma or skin cancer: People 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 melanoma: Melanoma 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, all family members should be checked regularly by a doctor.

Weakened immune system: People whose immune system is weakened by certain cancers, by drugs given following organ transplantation, or by HIV are at increased risk of developing melanoma.