Skin Cancer: Non-Melanoma
At a Glance
- Cancer that forms in the tissue of the skin is called skin cancer.
- Most skin cancers form in older people on parts of the body exposed to the sun or in people who have weakened immune systems.
- The major risk factor for skin cancer is exposure to the sun, however, there are numerous other risk factors (see below).
- A change on the skin is the most common sign of skin cancer. This may be a new growth, a sore that doesn’t heal, or a change in an old growth. Not all skin cancers look the same.
TYPES OF NON MELANOMA SKIN CANCER
There are several types of skin cancer.
Basal cell carcinoma– Skin cancer that forms in the lower part of the epidermis (the outer layer of the skin) is called basal cell carcinoma.
Squamous cell carcinoma– Skin cancer that forms in squamous cells (flat cells that form the surface of the skin) is called squamous cell carcinoma.
Neuroendocrine carcinoma (Merkel cell) – Skin cancer that forms in neuroendocrine cells (cells that release hormones in response to signals from the nervous system) is called neuroendocrine carcinoma of the skin, or merkel cell carcinoma or trabecular cancer.
Cutaneous lymphoma – Cancers of lymphocytes (white blood cells) that primarily involve the skin. Cutaneous lymphomas are a distinct subset of non-Hodgkin’s lymphoma.
Cutaneous Angiosarcoma – Cancer of the inner lining of blood vessels in the skin, usually found on the scalp and face. Angiosarcoma that appears underneath the surface of the skin is called subcutaneous angiosarcoma.
Mycosis Fungoides – A disease in which a type of white blood cell (lymphocytes) become malignant and affect the skin. It is a type of cutaneous T-cell lymphoma.
The skin is the body’s largest organ. It protects against heat, light, injury, and infection. It helps control body temperature. It stores water and fat. The skin also makes vitamin D.
The skin has two main layers:
- Epidermis: The epidermis is the top layer of the skin. It is mostly made of flat cells. These are squamous cells. Under the squamous cells in the deepest part of the epidermis are round cells called basal cells. Cells called melanocytes make the pigment (color) found in skin and are located in the lower part of the epidermis.
- Dermis: The dermis is under the epidermis. It contains blood vessels, lymph vessels, and glands. Some of these glands make sweat, which helps cool the body. Other glands make sebum. Sebum is an oily substance that helps keep the skin from drying out. Sweat and sebum reach the surface of the skin through tiny openings called pores.
ABOUT SKIN CANCER
Skin cancer begins in cells, the building blocks that make up the skin. Normally, skin cells grow and divide to form new cells. Everyday skin cells grow old and die, and new cells take their place. Sometimes, this orderly process goes wrong. New cells form when the skin does not need them, and old or damaged cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor. Growths or tumors can be benign or malignant.
Benign or non-cancerous growths are rarely life threatening, can be removed and do not spread to other parts of the body. On the other hand, malignant or cancerous growths may be life threatening, grow back after removal or spread to other parts of the body. The spread of cancer is called metastasis.
A risk factor is something that may increase the chance of developing a disease. Studies have found the following risk factors for skin cancer:
- Ultraviolet (UV) radiation: UV radiation comes from the sun, sunlamps, tanning beds, or tanning booths. A person’s risk of skin cancer is related to lifetime exposure to UV radiation. Most skin cancer appears after age 50, but the sun damages the skin from an early age.
- UV radiation affects everyone. But people who have fair skin that freckles or burns easily are at greater risk. These people often also have red or blond hair and light-colored eyes. But even people who tan can get skin cancer.
- People who live in areas that get high levels of UV radiation have a higher risk of skin cancer. In the United States, areas in the south (such as Texas and Florida) receive more UV radiation than areas in the north (such as Minnesota). Also, people living at higher altitudes are exposed to greater levels of UV radiation.
- UV radiation is present even in cold weather or on a cloudy day.
- Scars or burns on the skin
- Infection with certain human papillomavirus
- Exposure to arsenic at work
- Chronic skin inflammation or skin ulcers
- Diseases that make the skin sensitive to the sun, such as xeroderma pigmentosum, albinism, and basal cell nevus syndrome
- Radiation therapy
- Medical conditions or drugs that suppress the immune system
- Personal history of one or more skin cancers
- Family history of skin cancer
- Actinic keratosis: Actinic keratosis is a type of flat, scaly growth on the skin. It is most often found on areas exposed to the sun, especially the face and the backs of the hands. The growths may appear as rough red or brown patches on the skin. They may also appear as cracking or peeling of the lower lip that does not heal. Without treatment, a small number of these scaly growths may turn into squamous cell cancer.
- Bowen’s disease: Bowen’s disease is a type of scaly or thickened patch on the skin. It may turn into squamous cell skin cancer.
The best way to prevent skin cancer is to protect yourself from the sun. Also, protect children from an early age. Doctors suggest that people of all ages limit their time in the sun and avoid other sources of UV radiation:
- It is best to stay out of the midday sun (from mid-morning to late afternoon) whenever you can. You also should protect yourself from UV radiation reflected by sand, water, snow, and ice. UV radiation can go through light clothing, windshields, windows, and clouds.
- Wear long sleeves and long pants of tightly woven fabrics, a hat with a wide brim, and sunglasses that absorb UV.
- Use sunscreen lotions. Sunscreen may help prevent skin cancer, especially broad-spectrum sunscreen (to filter UVB and UVA rays) with a sun protection factor (SPF) of at least 15. But you still need to avoid the sun and wear clothing to protect your skin.
- Stay away from sunlamps and tanning booths.