Skin cancer is the most common type of cancer in the United States. In fact, one in five Americans will develop skin cancer in their lifetime. There are several causes and risk factors for skin cancer. The most common cause of skin cancer is exposure to ultraviolet (UV) radiation from sunlight and tanning beds.
Most skin cancers can be treated relatively easily when caught early. However, some kinds of skin cancer can be serious, even fatal. For this reason, you should have your doctor or dermatologist look at any suspicious areas on your skin.
The three main types of cancer are:
- Basal cell carcinoma
- Squamous cell carcinoma
Basal Cell Carcinoma
Basal cell carcinoma (BCC) is an abnormal and uncontrolled growth that develops in your skin’s basal cells. Your basal cells are located in your skin’s upper layer (the epidermis) and make new skin cells. BCC is the most common type of skin cancer. An estimated 2.8 million people in the United States are diagnosed with BCC each year; eight out of 10 skin cancers are basal cell carcinomas.
BCC is nonmelanoma skin cancer. Nonmelanoma skin cancers tend to grow slower and are less likely to spread throughout the body compared to melanoma. However, left untreated, BCC can destroy surrounding muscles, nerves, and bones and cause disfigurement.
Squamous Cell Carcinoma
Squamous cell carcinoma (SCC) is the abnormal and uncontrolled growth of squamous cells. Squamous cells make up the majority of your epidermis. SCC is the second most common type of skin cancer. An estimated 700,000 people in the United States are diagnosed each year with SCC. As with BCC, SCC is nonmelanoma skin cancer and grows slowly. SCC can also spread to other parts of your body, although this is rare.
Melanoma is the most serious and fatal kind of skin cancer. Melanoma develops when DNA damage to melanocyte skin cells causes them to multiply rapidly and form malignant (cancerous) tumors. Although less common than nonmelanoma skin cancer, melanoma is the most dangerous type of skin cancer. This is partly because cancerous melanocyte skin cells are more likely to spread to other parts of the body.
Melanoma is primarily caused by a history of severe sunburns. The more sunburns you‘ve had, the greater your risk of melanoma. Even one severe, blistering sunburn increases your risk of melanoma.
Melanoma comprises 4% of all skin cancers, but is responsible for over 75% of all skin cancer deaths. In 2013, it is estimated that 76,690 people will be diagnosed with melanoma and 9,480 people will die from the disease. However, if melanoma is caught and treated early, it is often cured.
Other Kinds of Skin Cancer
The following skin cancers make up less than 1% of all skin cancers combined:
- Kaposi’s sarcoma usually starts in the dermis but can form in organs. It is related to infection with Kaposi sarcoma herpesvirus and is more common in people with HIV/AIDS.
- Merkel cell carcinoma develops from neuroendocrine cells (hormone-making cells that are like nerve cells) in the skin. Merkel cell carcinoma is believed to be caused, in part, by exposure to the Merkel cell polyomavirus.
- Skin lymphoma starts in the lymphocytes of the skin. Lymphocytes are immune system cells found throughout the body.
- Skin adnexal tumor starts in the hair follicles or glands of the skin.
Early Detection and Treatment
While the number of people diagnosed with skin cancer is on the rise, early detection and treatment have caused death rates to drop. When treated early, doctors can cure nonmelanoma skin cancer.
For malignant melanoma, the outlook largely depends on how deeply the melanoma has grown into the skin, and whether it has spread to other parts of the body. Melanoma on the surface of the skin that is treated properly can be cured. In the United States, the overall five-year survival rate for melanoma that has not spread is about 98%. The survival rate falls to 62% if the disease spreads to lymph nodes, and 15% if the disease spreads to distant organs.