One in five Americans develops skin cancer over their lifetime, making it the most common form of cancer. Fortunately it is also one of the most preventable, since sun exposure is a major factor in its growth, according to the American Academy of Dermatology (AAD).
Symptoms & Types
Skin cancer doesn’t discriminate against race, and people of all colors can develop it. But symptoms greatly depend on the type of skin cancer present, which include:
- Actinic keratosis (AK): Considered the earliest stage of any skin cancer, AK is characterized by dry, scaly spots or patches. It typically appears on areas that are often exposed to the sun, such as the neck, hands, forearms and head. Most people who develop AK are fair-skinned.
- Basal cell carcinoma (BCC): The most common variety of skin cancer, BCC often appears as flesh-colored, pearl-like bumps, though it can also include pink-ish skin patches. It also develops on sun-exposed areas of skin, but does not grow quickly and rarely spreads.
- Squamous cell carcinoma (SCC): This cancer typically appears on sun-exposed skin areas and often resembles a scaly patch, firm bump or ulcer that heals and then re-opens, according to the AAD. It is the second most common type and can grow deep into the skin if not caught early, causing disfigurement.
- Melanoma: Almost 69,000 melanoma cases are diagnosed annually, according to the Skin Cancer Foundation, and 8,500 people die. The most common form of any cancer in adults age 25 to 29, melanoma often develops in an existing mole or appears suddenly as a new dark spot. Risk factors include having several large or many small moles; exposure to natural or artificial sunlight over long periods; a fair complexion with light eyes and red or blond hair; and a family history of unusual moles or melanoma.
Diagnosis & Tests
The first step in diagnosing skin cancer is a skin exam. Those who notice suspicious patches of skin that resemble one of the four types of skin cancer – or observes a rapid, unusual change in any mole’s size, shape or color – should seek prompt medical attention.
Doctors may be able to tell on sight if a skin irregularity is cancerous. Typically, however, a biopsy will be taken to confirm this. A small piece or the entire lesion will be removed and sent to a lab for testing. If the biopsy reveals cancer, it will also determine what type, according to the Mayo Clinic.
Once skin cancer is diagnosed, a doctor may initiate additional tests to tell the extent or if it has spread. For melanoma, the deadliest skin cancer by far, the survival rate for patients whose lesion is detected early is about 99 percent, according to the Skin Cancer Foundation. But those whose melanoma has spread have only a 15 percent chance of survival.
According to the Internet Journal of Gastroenterology, the most common site of melanoma metastasis beyond the lymph nodes is the small bowel, followed by the stomach, esophagus, rectum and colon.
A well-known method for recalling melanoma symptoms is the "ABCDE," which stands for:
- Asymmetrical skin lesion
- Border is irregular
- Color -- melanomas often are multi-colored
- Diameter – larger moles are more likely to be melanomas than small ones
- Enlarging -- enlarging or evolving
Treatment & Medications
Small, non-melanoma skin cancers may not require any treatment other than surgical removal. Other skin cancer treatments depend on the size, depth and location of the lesions, according to the Mayo Clinic.
- Freezing with liquid nitrogen.
- Laser therapy to vaporize growths.
- Mohs surgery, which removes growths layer by layer until no abnormal cells remain. This treatment is usually reserved for larger, recurring skin cancers.
- Radiation, when surgery isn’t an option.
- Chemotherapy, which can include topical creams containing imiquimod or diclofenac, or systemic drugs such as dacarbazine (commonly known as DTIC) or temozolomide (Temodar).
- Biological therapy using the drugs interferon or interleukin-2 to stimulate the immune system to kill abnormal cells.
- Photodynamic therapy (PDT), which uses a combination of lasers and drugs that make cancer cells vulnerable to light.
- Curettage and electrodessication, which uses a circular blade called a curette and an electric needle to scrape away and destroy lesions
According to the AAD, sun exposure is the most avoidable risk factor for skin cancer of all types. Preventive measures include:
- Using a broad-spectrum sunscreen daily with a sun protection factor (SPF) of 30 or higher.
- Seeking shade, especially between 10 a.m. and 4 p.m. when the sun is strongest.
- Wearing protective clothing such as long-sleeved shirts, pants, hats and sunglasses
- Avoiding tanning beds