Skin Cancer

By Peter K. Lee, M.D., Ph.D.
Updated June 7, 2007
(Originally posted May 20, 2006)

As the weather grows warmer and more of us head outdoors, we Minnesotans need to protect ourselves from the sun’s harmful rays that can lead to most common cancer: skin cancer. While more than 1 million Americans will receive a skin cancer diagnosis this year, it is important to realize that when it is caught and treated early, skin cancer is highly curable.

There are three main types of skin cancer: basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. Basal cell carcinoma is the most common; it is slow growing and usually appears as a red, bleeding, non-healing lesion. If left untreated, BCC will grow, damaging the skin and potentially invading nearby muscle, cartilage, and bone.

Squamous cell carcinoma is the second most common type of skin cancer. It can grow more quickly than BCCs, and untreated, it can spread to lymph nodes or other organs. SCC begins as a flat or raised red scaly, rough area that is tender and may bleed.

Melanoma is most deadly and least common form of skin cancer that can begin in pre-existing moles or in a newly formed lesion. It has a high potential to spread to lymph nodes or other organs. Melanomas often appear in shades of brown and black, and have irregular borders and shape. Melanomas can be itchy but often do not exhibit any symptoms. While most moles are harmless, regular self-exams are important so you can tell your doctor or dermatologist about areas of concern. Flat dark moles are usually more concerning than raised ones.

Treatment for skin cancer varies depending on the type of cancer and stage of the disease.  Surgical removal is the most common and best option. However, other treatments are available, including topical creams, radiation, chemotherapy, and immunotherapy. 

You play a large role in reducing your risk of skin cancer. The largest risk factor for developing skin cancer is exposure to ultraviolet (UV) radiation from the sun or artificial sources. You can protect yourself from UV rays by avoiding prolonged sun exposure during peak hours of 11 a.m. to 3 p.m., wearing protective clothing and wide-brimmed hats, and applying sunscreen to areas exposed to the sun.

Not all sunscreens are created equal.  Look for products that have a sun protection factor (SPF) of at least 30, that protect against ultraviolet A and B light. Products that contain titanium dioxide or zinc oxide also provide a physical block to the UV rays. Apply sunscreen to the skin 15-20 minutes before sun exposure, and be sure to reapply throughout the day. Also remember to check the expiration dates, as sunscreen loses effectiveness.

The American Cancer Society recommends skin examinations every three years for people ages of 20 and 40, and every year for those who have had skin cancer in the past or are older than 40. Additionally, if you have a first-degree relative with history of skin cancer, especially melanoma, your risk of getting a skin cancer is much higher.

Peter K. Lee, M.D., Ph.D., is the Director of the Dermatologic Surgery and Laser Center and is an Assistant Professor in the Department of Dermatology at the University of Minnesota. This column is an educational service of the University of Minnesota. Advice presented should not take the place of an examination by a health-care professional. For more health-related information, go to http://www.healthtalk.umn.edu.