Skin cancer is the most common type of cancer in humans. Each year, over one million people will develop skin cancer in the United States.
If you have recently been diagnosed with skin cancer, you are not alone. In the skin, 96% of all new cases of skin cancer are basal cell carcinoma (75%) and squamous cell carcinoma (16%). Basal cell carcinoma and squamous cell carcinoma are distinct from melanoma, a less common type of skin cancer.
These names come from the name of the type of cell that becomes cancerous, a basal cell, a squamous cell, or a melanocyte.
Cancer is a very frightening word that is used to describe many very different diseases with many very different prognoses. Some cancers are more dangerous than others, but fortunately skin cancers are generally curable when treated early and appropriately. A cancer means that a cell is replicating faster than it normally should. Most cells that make up the body divide and reproduce in an orderly manner. This allows the body to grow, replace worn-out tissue, and repair injuries. If one of these cells is injured in some way (for example, by the sun) and becomes cancerous, it begins to replicate and divide much more quickly. With the cell dividing more rapidly, the body is unable to process all of the new cells and a mass of these cells is formed. This mass of new cells is called a tumor.
If left untreated, skin cancer will continue to grow and could destroy healthy surrounding tissue. In some cases, the cancer cells may even spread to other parts of the body. This process is called metastasis and is associated with more dangerous forms of cancer. This almost never occurs in basal cell carcinomas and is rare seen in squamous cell carcinomas that are smaller than 2 cm in size. Although not common with today’s advanced diagnostic and therapeutic methods, melanoma is more likely to metastasize and spread to other parts of the body such as the lungs, liver, and bones than other forms of skin cancer.
Basal cell carcinomas (BCC) and squamous cell carcinomas (5CC) grow from specific cells in the outermost layer of the skin. The tumor may begin as a small bump that looks like a “pimple that doesn’t go away”. It gradually enlarges, and sometimes bleeds. The cancer may appear red, pearly, scaly, flesh-colored, or darker than the surrounding skin.
Basal cell carcinoma
This is the most common form of all cancers in this country. It accounts for about 75% of all skin cancer and has the best prognosis. This tumor almost never spreads to the lymph nodes or distant parts of the body, and is therefore very rarely life-threatening. However, it is locally destructive and can be especially problematic when it involves structures on the face and neck. Although it is extremely unusual for a basal cell carcinoma to metastasize, if left untreated, these tumors will continue to grow to very large sizes and may invade bone and other tissues beneath the skin.
Squamous cell carcinoma
This is the second most common skin cancer. Squamous cell carcinomas, especially when they are larger than 2 cm in width, can be a more aggressive than basal cell carcinomas. These skin cancers usually grow more quickly, are more likely to invade structures beneath the skin and may spread (metastasis) to distant areas of the body. Still, only approximately 5% of squamous cell carcinomas actually do metastasize, most often to local lymph nodes. Risk for metastasis is increased for larger, untreated tumors and in patients who are immunosuppressed. However, most squamous cell carcinomas of the skin remain localized and do not spread.
This is one of the most dangerous forms of skin cancer if not treated early. Malignant melanoma generally appears as a brown or black patch, with shades of red or purple in it. They may arise on their own or develop in a pre-existing mole. Mohs surgery is not usually used for this form of skin cancer. However, a superficial form of malignant melanoma known as lentigo maligna may be treated with a modified form of Mohs surgery.
WHY DO PEOPLE GET SKIN CANCER?
Long-term exposure to sunlight is the single most important factor in the formation of skin cancer.
After years of ultraviolet exposure from the sun, a normal basal or squamous cell on our skin may be transformed into a cancerous cell. As a cancerous cell, it will begin to divide much more rapidly than the body is used to, forming a skin cancer. Skin cancers therefore occur most often on sun-exposed areas of the body, particularly the head and neck. Although skin cancer typically arises in middle to older patients with fair complexion who sunburn easily, skin cancers are being seen more and more frequently in the younger population and in people of darker skin complexions. In our practice, we regularly see this type of skin cancer in adults in their thirties, or even twenties, and in people of Asian, Southeast Asian, or Hispanic descent.
Superficial X-rays, used many years ago for treatment of certain skin diseases, and tanning bed use may contribute to the development skin cancer many years later. Trauma (scars), certain chemicals, and certain rare inherited diseases may also contribute to the development of skin cancer. Transplant patients and those who are on immunosuppressive medications are also at higher risk of getting skin cancer.
Although the effects of the sun’s rays are cumulative, there are usually many years separating the significant exposure to the sun and the formation of the skin cancer. The majority of sun exposure generally occurs during the teenage years and early twenties, while most skin cancers do not begin to occur until one’s forties. The skin never forgets any of the sun it has received.
WHY SHOULD I GET THIS TREATED?
I am often ask if it is necessary to treat basal cell carcinoma and squamous cell carcinoma. Often the biopsy seems so small and the area so trivial. Nevertheless, if left untreated, skin cancer can grow. This is a great article entitled “One Doctor’s Confession: Basal And Squamous Cell Skin Cancers Are NOT Benign” from Dr. J. Leonard Lichtenfeld, the Deputy Chief Medical Officer for the American Cancer Society.
The best way to protect yourself from future skin cancers is to make a serious attempt at reducing the amount of sunlight you are exposed to. Whenever you will be exposed to the sun you should always apply a broad spectrum sun screen with a Sun Protection Factor (SPF) of 30 or greater. Also, one should wear a broad brimmed hat and limit your exposure to the sun during midday (10 AM to 3 PM), when the rays are most intense. You don’t have to change your entire lifestyle, just alter it intelligently and take the proper precautions.