Skin CancerBy: P. Michael Shattuck, M.D. – Community Health Network Family Physician
Skin cancers are the most common form of cancer. It is estimated that about 40% of all cancers are skin cancers. There are three major types of skin cancer. These include basal cell cancer, squamous cell cancer, and melanoma. This article will focus on these cancers.
Skin cancers are closely related to sun exposure. It is the ultraviolet radiation that seems to cause the skin damage and the risk for cancer. Certain individuals tend to be more prone to these cancers. Fair skin with light complexion, freckles, blond or red hair, and blue or green eyes tend to be characteristics of people who are more prone to skin cancer. A family history of melanoma in a close relative also tends to increase risk.
By definition, cancer is diagnosed when cells grow out of control and invade other tissue. The diagnosis is confirmed by a skin biopsy. Our immune system helps to monitor the skin for abnormal cells and can stop them from growing. So, individuals with immune system diseases or those on immune system suppressing medications are also at increased risk. Increasing age is also a factor for basal cell and squamous cell cancers. However, I have taken basal cell cancers off of individuals in their 20’s. Melanoma can also occur in younger individuals. It is reported that melanoma is the most common cancer in people 25-30 years old.
Basal cell cancers are the most common of all cancers and the most common type of skin cancer. This cancer arises primarily in sun exposed areas from cells in the basal layer of the skin that grow abnormally. The most common presentation is a sore that won’t heal, but can be a nodule or spot that grows over months and generally does not cause pain. Basal cell cancers are generally successfully treated with minor surgery and rarely if ever spread beyond the site where it started.
Squamous cell cancers are the next most common skin cancer. These cancers arise in the top layer or squamous layer of the skin. Like basal cell cancers, they tend to occur in sun exposed areas like the face, nose, ears, shoulders, neck, forearms and backs of the hands. These cancers can present as a sore but commonly appear as hard crusty growths. It is felt that these cancers may develop from an abnormal skin growth called an actinic keratosis. These “precancerous growths” can be treated by freezing with liquid nitrogen or creams. Once it has progressed to squamous cell cancer it can be treated with freezing, surgery, or topical chemotherapy.
Melanomas make up about 5% of all skin cancers, but they cause nearly 100% of skin cancer deaths. In 2010 there were over 9,000 deaths due to melanoma with over 60,000 cases diagnosed In the USA. These cancers arise from the melanocytes or pigment producing cells of the skin. Melanomas can occur in young people and are mostly in sun exposed areas but can occur anywhere. The characteristics to watch for in a mole are asymmetry (meaning it tends to have an irregular shape), irregular borders, and changes in color especially dark or black tissue, and growth of the mole. Melanomas are best treated with surgery when found early. The danger of melanoma is that it can spread to other parts of the body from where it started. If it spreads the treatment becomes much more difficult.
As discussed last week, protecting the skin from intense sun exposure with sun block, clothing, lip balm, and shade can reduce the risk of skin cancer. Monitoring the skin for suspicious spots and having them checked by a health care provider can help manage and prevent complications from skin cancer. So, watch for spots that are new, changing, or not healing. Take good care of your skin and stay healthy my friends.