Skin Cancer Overview
Skin cancer is the abnormal growth of skin cells. In this disease the malignant or the cancerous cells form in the tissues of the skin.
As known the skin is the body’s largest organ. It gives a good protection against heat, sunlight, injury, and infection.
Skin also helps control body temperature and stores water, fat, and vitamin D.
Types of Skin Cancer
The skin cancer is categorized into three major types depending on their origin. They are the basal cell carcinoma, squamous cell carcinoma and melanoma.
All these three types of skin cancer are common. The first two types of skin cancers are termed as nonmelanoma skin cancers. Actinic keratosis is a skin condition that sometimes develops into squamous cell carcinoma.
The best part of skin cancer is that any type can be pretty well prevented. As the major cause of any type of skin cancer is exposure to ultraviolet (UV) radiation this can be avoided by taking certain precautionary measures.
Along with this a thorough observation of any slight skin change is needed for early detection. The treatment gives better results if the disease is detected at an early stage.
The anatomy of the skin says that skin has several layers, but the two main layers are the outer and the inner layers. The outer layer is the epidermis and the inner layer is the dermis. The outer layer of the skin the epidermis is made of three types of cells and the skin cancer can occur in any of these cells. They are the
- Squamous cells: Thin, flat cells that form the top layer of the epidermis.
- Basal cells: Round cells under the squamous cells.
- Melanocytes: make the melanin, the pigment that gives skin its natural color. These are found in the lower part of the skin. When skin is exposed to the sun, melanocytes make more pigment, causing the skin to darken.
Skin cancer can occur anywhere on the body. Most often develops on skin exposed to the sun such as the face, neck, hands, and arms. But this common form of cancer also can occur on areas of the skin not ordinarily exposed to sunlight.
A cancerous skin lesion can appear suddenly or develop slowly giving an indication or early signs of skin cancer. Its appearance depends on the type of cancer. Each type of skin cancer has its own varied symptoms or signs.
Skin Cancer and UV light
The cause of Skin cancer is well predicted as the UV light. According to the research it is proved that both the UVA and UVB rays play a role in causing the harmful changes in the skin cell DNA.
They also play a major role in development of the oncogenes responsible for development of skin cancer. Until recently it is was considered that only UVB rays are responsible for skin cancer but latest studies show the involvement of UVA rays also.
The UVA weakens the skin's immune system and increases the risk of skin cancer, especially melanoma. The oncogenes turn the normal cell into the malignant. Other factors that may contribute to skin cancer are heredity and also exposure to toxic chemicals or as a result of radiation treatments.