by Martha L. Prendergast, LDH, and Sally A. Leicht, LDH, RDH, BS, MBA
The dental hygienist needs to go beyond the routine head and neck exam - it is just as important to look at the skin on an exposed arm or leg as it is on the head and neck. As dental hygienists, we want to help bridge the gap that often exists between the dental and medical community. We need to share in the responsibility and work as a team with medical professionals to educate, identify, and refer our patients for skin cancer checkups and the treatment of suspicious lesions.
The skin is the largest organ of the body.1,8 There are more than one million skin cancers diagnosed each year in the United States.2,6 That’s more than cancers of the prostate, breast, lung, colon, uterus, ovaries, and pancreas combined.2 The number of skin cancers has been on the rise for the past few decades.2 This is why it is so important to be able to identify normal vs. abnormal and any suspicious skin lesions. Ignorance is not always bliss; it can come with a great deal of irresponsibility and failure to perform and inform.
Skin cancers involve abnormal cell changes in the outer layer of the skin called the epidermis.5 Skin cancer is the most common cancer in the world. Most cases are cured, but the disease is a major health concern because it affects so many people.3 The incidence of skin cancer is rising, even though limiting the skin’s exposure to ultraviolet radiation could prevent most cases.3 See Table 1 to learn more about sunscreen.2
Skin cancers fall into two major categories: melanoma and nonmelanoma.3 Nonmelanoma skin cancers are the most common cancers of the skin.4 They are called nonmelanoma skin cancer because they develop from skin cells other than melanocytes.5
There are many types of nonmelanoma skin cancers, but two types are most common: basal cell carcinoma and squamous cell carcinoma. Basal cell carcinoma begins in the lowest layer of the epidermis, called the basal cell layer. About 70 to 80 percent of all skin cancers in men and 80 to 90 percent in women are basal cell carcinomas. They usually develop on sun-exposed areas, especially the head and neck. Basal cell carcinoma was once found almost exclusively in middle-aged or older people. Now it is also being seen in younger people, probably because they are spending more time in the sun with their skin exposed. Basal cell carcinoma is slow-growing. It is highly unusual for a basal cell cancer to spread to lymph nodes or distant parts of the body. However, if a basal cell cancer is left untreated, it can grow into nearby areas and invade the bone or other tissues beneath the skin.4
The five most typical characteristics of basal cell carcinoma are described and pictured in Figure 1.6
Frequently, two or more features are present for one tumor. In addition, basal cell carcinoma sometimes resembles noncancerous skin conditions, such as psoriasis or eczema. Only a trained physician, usually a dermatologist, can decide for sure.7 Remember, a prompt diagnosis can ultimately save a life!
After treatment, basal cell carcinoma can recur in the same place on the skin. Also, new basal cell cancers can start elsewhere on the skin. Within five years of being diagnosed with one basal cell cancer, 35 to 50 percent of people develop a new skin cancer.4
Squamous cell carcinomas account for about 10 to 30 percent of all skin cancers. They commonly appear on sun-exposed areas of the body such as the face, ear, neck, lip, and back of the hands. They can also develop in scars or skin ulcers elsewhere. Less often, they form in the skin of the genital area.4
The warning signs of squamous cell carcinoma are described and pictured in Figure 2.6,8
Squamous cell carcinomas tend to be more aggressive than basal cell cancers. They are more likely to invade fatty tissues just beneath the skin and slightly more likely to spread to lymph nodes and/or distant parts of the body, although this is still uncommon.4
The most serious form of skin cancer is melanoma, which was expected to be diagnosed in about 62,190 people in 2006.9 Melanoma skin cancer is a cancer that begins in the melanocytes, the cells that produce the skin coloring or pigment known as melanin.5,10 Melanin helps protect the deeper layers of the skin from harmful effects of the sun.5,10,11
Melanoma consists of melanocytes, which have been transformed into cancer cells that grow abnormally. Melanoma cells usually still produce melanin; this is why these cancers may have mixed shades of tan, brown, and black. Unlike basal cell and squamous cell carcinomas of the skin, which do not commonly spread to other parts of the body, melanoma can spread if not detected at an early stage. Once melanoma cells reach vital internal organs and grow, they are more difficult to treat and less likely to be cured. While melanoma may appear in the skin without warning, it may begin in or near a mole or other dark spot in the skin.10
Moles, brown spots, and growths on the skin are usually harmless, but not always.12 Anyone who has more than 100 moles is at greater risk for melanoma.12 Look for the ABCDEs of melanoma, as described and pictured in Figure 3.6
Prompt action is your best protection. Common moles and melanomas do not look alike.12
Like basal cell and squamous cell cancers, melanoma is almost always curable in its early stages.2,5 It is much more likely than basal or squamous cell cancer to spread to other parts of the body, where it can be very hard to treat.2,5 Although melanoma accounts for only a small percentage of skin cancer, it is far more dangerous than other skin cancers, and it causes the majority of skin cancer deaths.10
As a dental health care professional, it is vital for the overall health of our patients that we educate ourselves on the subject of skin cancer. Becoming familiar with the various types of skin cancer, what to look for, and risk factors can help us provide the most competent care for our patients. See Table 2 for a list of risk factors.10 Let us be mindful that the job of prevention should not rest solely on the medical community. The dental community can help make a difference as well. See Table 3 for some prevention tips.10
It is time for the dental team to think outside the mouth and help close the gap that inevitably remains between the dental and medical communities. Remember, there is more to hygiene than instrumentation. As dental hygienists, we need to expand our way of thinking and stop practicing with tunnel vision. The next time you give your patients oral hygiene instruction, think about coupling it with a little skin cancer instruction. RDH
Author acknowledgement: Thank you to Patti DiGangi, RDH, BS, for agreeing to be our mentor. Also, thank you to Marcus W. Malczewski, DDS, for his confidence and encouragement as our friend and employer.
- What is melanoma skin cancer? 4/24/06. American Cancer Society, Inc. Available at: http://www.cancer.org/docroot/CRI/content_2_21X_What_is_melanoma_skin_cancer_50.asp?sitearea=. Accessed 10/31/2006.
- Skin cancer prevention and early detection. 4/27/06. American Cancer Society, Inc. Available at: http://www.cancer.org/docroot/PED/content/ped_7_1_Skin_Cancer_Detection_What_You_Can_Do.asp?sitearea=&level. Accessed 10/31/06.
- Understanding skin cancer - the basics. 8/05. American Cancer Society. National Cancer Institute. American Academy. Available at: http://aolsvc.health.webmd.aol.com/content/article/54/61572.htm?SRC=aolKW=skincancer. Accessed 7/2/06.
- What is nonmelanoma skin cancer? 3/22/06. American Cancer Society, Inc. Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_4_1X_What_is_skin_cancer_51.asp. Accessed 10/31/06.
- American Cancer Society. Melanoma: treatment guidelines for patients. Version III/Sept. 2005. Page 7.
- Images courtesy of the Skin Cancer Foundation, New York, New York. www.skincancer.org.
- Basal cell carcinoma. 2006. The Skin Cancer Foundation. Available at: www.skincancer.org/basal/index.php. Accessed 12/31/06.
- Squamous cell carcinoma. 2006. The Skin Cancer Foundation. Available at: www.skincancer.org/squamous/index.php. Accessed 12/31/06.
- American Cancer Society. Cancer Facts and Figures 2006. Atlanta: American Cancer Society.
- Skin cancer facts. 4/05/06. American Cancer Society, Inc. Available at: http://www.cancer.org/docroot/PED/content/ped_7_1_What_You_Need_To_Know_About_Skin_Cancer.asp?sitearea=&level. Accessed 10/31/06.
- American Cancer Society. Why you should know about melanoma. 2002. Page 2.
- Melanoma. 2006. The Skin Cancer Foundation. Available at: www.skincancer.org/melanoma/index.php. Accessed 12/31/06.