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Malignant melanoma is diagnosed in Poland in about 2,000 people annually, of which up to 15 percent is a family form of genetic origin. About 25-40 percent of hereditary malignant melanoma is due to a mutation in the CDKN2A gene. Check when it is worth having a genetic test for melanoma.

Malignant melanomais one of the most malignant neoplasms. It is derived from pigment cells of neuroectodermal origin (melanocytes) which, in the early stages of embryonic development, move from the neural tube to organs and tissues (skin, eye, meninges, genitourinary system, etc.). These cells condition the skin complexion (phenotype) and its sensitivity to ultraviolet (UV) rays, synthesizing and secreting a specific pigment - melatonin.

Due to the fact that the most melanocytes are found in the epidermis, the skin is the most common starting point for melanoma. However, it is not the only place where this cancer develops, as these cells are also found in other tissues and organs. Almost one in 10 melanomas develops primarily elsewhere, most often in the mucous membranes of the genitals and mouth, and in the eyeball.

Malignant melanoma accounts for approx. 1% of all diagnosed neoplasms, yet it is a significant problem, as in recent years there has been a significant increase in the incidence of this neoplasm and due to the relatively young age of patients (30-50 years). The increase in the incidence concerns mainly the white race. In Poland, approximately 2,000 are diagnosed annually. cases of malignant melanoma, of which up to15% is a family form with a genetic background .

Inheriting the predisposition to malignant melanoma

Hereditary malignant melanomaapproximately 25-40% of cases are caused by mutations in the CDKN2A gene located on chromosome 9p21. The variant p.A148T is observed in 3.5% of the Polish population, increasing the risk of developing melanoma. Mutations damaging the CDKN2A gene in other regions lead to the development offamilial pancreatic melanoma-cancer syndrome . The inheritance of the predisposition to falling ill is dominant, i.e. it is enough to receive a damaged gene from one of the parents to have an increased risk of falling ill.

How to recognize melanoma?

Important

Identification of the CDKN2A gene mutation may be important in examining family predisposition to developmalignant melanoma , in diagnosis and prognosis, and even influencing the choice of therapy. However, it should be emphasized that neoplastic diseases (including melanoma) are not strictly hereditary diseases. Only the predisposition to the disease related to permanent changes in the genome is inherited.

Development of malignant melanoma

Familial malignant melanoma is diagnosed early, usually before the age of 50. (a gradual decrease in the age of the patients is noticeable). Sometimes there is a family history of tumors in other organs (pancreas, early breast cancer) and possibly other types of cancer (lung cancer). Malignant melanoma usually originates from moles (pigmented skin lesions), its growth is accompanied by enlargement, inflammatory edema, ulceration, itching and bleeding.

It is believed that people with moles should observe the changes that occur within them. In the event of any of the symptoms listed above, it is recommended to contact a doctor.

Melanoma diagnosis and prognosis

Cancer is often located on exposed parts of the skin or in areas prone to mechanical irritation, and is often multifocal. It is characterized by early metastasis, low drug sensitivity, and therefore high mortality. Doctors emphasize, however, that early diagnosis of melanoma gives a chance for complete recovery. In countries with high incidence, but also with a very developed social awareness and sensitivity of the medical community, approx. 90% of cases are diagnosed in the initial stage (limited to the skin / mucosa). In Poland, most patients visit a doctor with already advanced melanoma and the presence of metastases.

Malignant melanoma: indications for a genetic test

  • family history of melanoma (at least 2 among the closest relatives), especially before the age of 50;
  • suspicion of melanoma-pancreatic cancer syndrome (at least 2 cases of melanoma and / or pancreatic cancer among the closest relatives), especially with the presence of other neoplasms in the family, e.g. early breast cancer;
  • skin type sensitive to UV radiation (light complexion, red or blonde hair, blue irises, numerous freckles), a large number of congenital pigmented moles, with prolonged exposure to the sun and ultraviolet radiation or with sunburn (especially in childhood) ;
  • detection of CDKN2A gene mutations in relatives.

To prevent the development of the disease

Due to the limited effectiveness of the treatment of advanced melanoma and the unique malignancy of this cancer, the most important role is played by improving he alth habits and screening tests, allowing for early diagnosis of the disease. People at high risk should use sun protection (creams with an SPF of at least 15, depending on the phenotype of the skin) and carefully inspect skin lesions, especially in areas exposed to sunlight.

Preventive, early removal of suspicious nevi and their histopathological examination is recommended. Factors increasing the risk of malignant skin lesions are: mechanical irritation of moles, excessive sun exposure, UV exposure and immunosuppression.

Oncological supervision is also recommended: dermatological examination every 6 months for patients and closest relatives, and in families with other neoplasms, screening should be extended to include the endangered organ. Genetic testing of the CDKN2A gene, confirming the hereditary predisposition to the disease, enables prophylaxis to be extended to asymptomatic relatives of the patient - mutation carriers.

Before performing the test, it is worth consulting a geneticist who will select the appropriate test.

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Category:

Dermatology