What is it?
Skin cancer is a malignant tumor composed of skin cells that have undergone transformation and multiply in a disorderly way, giving rise to an abnormal new tissue. Among the causes that predispose to cell transformation, prolonged and repeated exposure to ultraviolet radiation from the sun appears as the main agent.
Skin cancer primarily affects white-skinned people who burn easily and never tan, or tan with difficulty. About 90% of lesions are located on skin areas exposed to the sun, which shows the role of sun exposure as its cause. Sun protection is therefore the main form of prevention.
Characteristics and symptoms
There are three most frequent types. They originate from different skin cells.
- Basal cell carcinoma: derived from the basal layer of epidermis, is the most frequent and has the lowest potential for malignancy. Its growth is slow and very rarely spreads to other organs.
Manifests itself in many ways, the photo above is just one of them. Wounds that don't heal or bleed easily due to minor trauma, such as rubbing the towel, may be a basal cell carcinoma. Learn more about basal cell carcinoma...
- Squamous cell carcinoma: derived from the cells of the spinous layer of epidermis, presents faster growth and larger lesions may metastasize (send cells to other organs). Also known as epidermoid carcinoma, is less common than basal cell carcinoma.
Besides sun damaged skin, it also affects areas of mucosa, such as the mouth or lip, old burn scars or areas that were irradiated by X rays.
It may also arise from actinic keratoses, which are considered precancerous lesions and result from prolonged and repeated exposure of the skin to the sun. Learn more about squamous cell carcinoma...
- Melanoma: derived from melanocytes (the cells that produce skin pigment), is the most dangerous skin cancer. Often sends metastasis to other organs, therefore being extremely important its early diagnosis to achieve cure.
Melanoma can arise from the normal skin or from melanocytic nevus which undergoes transformation. Despite being more common in areas of skin commonly sun exposed, melanoma can also occur in other areas.
People who have pigmented lesions (melanocytic nevus) on the skin should protect themselves from the sun, which can stimulate their transformation. At the presence of any changes in the lesions, such as color change, increase in size, bleeding, itching, inflammation or appearance of pigmented spots around it, a visit to the dermatologist is recommended.
Furthermore, some characteristics of the lesions can recommend the examination, according to the ABCD of melanoma:
- Asymmetry: irregular shape
- Jagged Borders: irregular outer limits
- Different shades of Color
- Diameter greater than 6mm (a pencil size)
The photo above is of an early-stage melanoma (melanoma in situ), with all the features described above. At this stage, melanoma is still restricted to the outermost layer of skin, where it doesn't send metastasis to other organs and can be cured by surgical excision. Learn more about malignant melanoma...
The prolonged and repeated skin exposure to the sun predispose to the appearance of cancer. Taking some precautions, its damaging effects may be avoided. Learn how to protect your skin from solar radiation:
- always use a sunscreen with sun protection factor (SPF) 15 or higher, applying it generously at least 20 minutes before sun exposure and always reapply it after bathing or excessive sweating;
- avoid the sun during the period between 10AM to 3PM;
- the vast majority of skin cancers appear on the face, protect it always using hats or caps, besides the sunscreen. Do not forget to protect your lips and ears, sites commonly affected;
- find a dermatologist if there are lesions on your skin that are changing, form crusts on the surface, bleed easily or if you have wounds that don't heal or lesions of progressive growth;
- make an annual visit to the dermatologist to evaluate your skin and treat any precancerous lesions.
These recommendations are especially important for people with skin types I and II, which should avoid any exposure to the sun without protection.
Sun protection should start early in life. About 75% of solar radiation received throughout life occurs within the first 20 years. The effects of ultraviolet radiation will become apparent only many years later, most often around age 40. Therefore, protect children and encourage adolescents to protect themselves.
Do not be afraid of the diagnosis. See your dermatologist if you have any suspicious lesion on your skin. Skin cancer can be cured and an early diagnosis is very important to achieve it. Furthermore, treatment of premalignant lesions, which can lead to skin cancer, helps its prevention.
Treatment of skin cancer is surgical in most cases or, in specific cases, by the destruction of lesions through radiotherapy or cryosurgery with liquid nitrogen. The earlier the lesion is removed, the greater the chance of cure and preventing the spread of cancer cells to other organs (metastasis), which is very rare in basal cell carcinoma but very common in cases of untreated melanoma.
- Basalcell carcinoma
- Squamouscell carcinoma
- Malignant melanoma