What is Skin Cancer?
The skin is the body's largest organ. Its job is to protect internal organs against damage, heat and infection. The skin is also the most exposed organ to sunlight and other forms of harmful ultraviolet rays. There are three major types of skin cancer.
- Basal cell carcinoma: The most common form of skin cancer. These cancers begin in the outer layer of skin (epidermis).
- Squamous cell carcinoma: The second most common type of skin cancer. These cancers also begin in the epidermis.
- Melanoma: The most serious skin cancer, it begins in skin cells called melanocytes that produce skin color (melanin).
If caught and treated early, most skin cancers can be cured. Be sure to talk to your doctor about anything unusual on your skin.
Diagnosis
If initial test results show abnormal skin cells, your doctor may refer you to a skin specialist called a dermatologist. If the dermatologist thinks that skin cancer may be present, a biopsy, or sample of skin from the suspicious area, will be checked for cancer.
There are three types of biopsies to test for skin cancer:
- Shave biopsy: The doctor "shaves" or scrapes off the top layers of the skin with a surgical blade.
- Punch biopsy: This type removes a deeper skin sample with a tool that resembles a tiny cookie cutter.
- Incisional and excisional biopsies: For an incisional biopsy, a surgeon cuts through the full thickness of skin and removes a wedge for further examination. An excisional biopsy is when the entire tumor is removed.
Other tests such as a chest X-ray, CT scan or MRI may be used to see if the cancer has spread to other parts of the body.
Risk Factors
There are many risk factors for developing skin cancer ranging from sun exposure to moles to family history:
- Exposure to ultraviolet rays and sunburn: The amount of exposure depends on the intensity of the light, length of time the skin was exposed, and whether the skin was protected with either clothing or sunscreen. Severe sunburn in childhood or teenage years can increase the risk of skin cancer.
- Skin coloring/pigmentation: People with fair skin are 20 times more likely to develop skin cancer than people with darker skin. Caucasian people with red or blonde hair and fair skin that freckles or burns easily are at the highest risk. People with darker pigmentation can also develop skin cancer, more likely on the palms of the hands, soles of the feet, under the nails or inside the mouth.
- Moles: Individuals with moles may be at increased risk of developing melanoma, especially if the moles are unusual, large or multiple.
- Family history: Risk of developing melanoma is higher if one or more members of a person's immediate family have been diagnosed.
- Immune suppression: People who have illnesses affecting their immune system (such as HIV) or who are taking medicines to suppress their immune system (such as after an organ transplant) are at an increased risk of skin cancer.
- Occupational exposure: Individuals exposed to coal tar, pitch, creosote, arsenic compounds or radium are at increased risk to develop skin cancer.
Signs and Symptoms
Skin cancer can be detected early and it is important to check your own skin on a monthly basis. You should take note of new marks or moles on your skin and whether or not they have changed in size or appearance.
The American Cancer Society's "ABCDE rule" can help distinguish a normal mole from melanoma.
The American Cancer Society recommends a skin examination by a doctor every three years for people between 20 and 40 years of age and every year for anyone over the age of 40.
Treatment
The treatment you receive depends on several factors including your overall health, stage of the disease and whether the cancer has spread to other parts of your body. Treatments are often combined and can include:
- Radiation therapy where the cancer cells are killed by X-rays.
- Surgery where the cancer cells are cut out and removed.
- Electrodessication where the cancer is dried with an electric current and removed.
- Cryosurgery where the cancer is frozen and removed.
- Laser surgery where the cancer cells are killed by laser beams.
- Chemotherapy where the cancer cells are attacked by a drug that is either taken internally or applied on the skin.
- Photodynamic therapy where the cancer is covered with a drug that becomes active when exposed to light.
- Biologic therapy where doctors help your immune system better fight the cancer.