Protect Your Skin

Skin cancer is the most common form of cancer in the United States.¹ Each year, approximately 3.5 million skin cancers are diagnosed in more than 2 million people.¹ Age, family history of skin cancer, and living at higher elevations all increase the risk of skin cancer but anyone who has been exposed to sun and ultraviolet (UV) rays without protection is at risk.

Skin cancers are typically classified as: nonmelanoma basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. (Table 1 provides a list of symptoms for each type.) Skin cancer is associated with the uncontrolled growth of abnormal, rapidly dividing skin cells. Human skin consists of three basic layers (epidermis, dermis, hypodermis) and several kinds of cells. The outer layer, the epidermis, contains three kinds of cells: squamous cells, basal cells, and melanocytes. The middle layer or dermis is composed of collagen, elastic tissue, and reticular fibers situated between the epidermis and the bottom layer of subcutaneous tissues. Skin cancers differentiate themselves within these layers.

PRECANCEROUS GROWTHS

Actinic keratosis (AK) or solar keratosis is a precancerous growth on the skin that may progress into cancer if left untreated (Figure 1). Commonly seen in older adults after decades of sun exposure and almost always as multiple lesions, AKs usually appear as dry scaly or crusty areas on the bald scalp, face, ears, lips, backs of the hands and forearms, shoulders, or neck. As a precaution, AKs are routinely treated because it is difficult to determine which lesions will become cancerous. About 65% of all SCCs originate from lesions that previously were diagnosed as AKs.²

BASAL CELL CARCINOMA

BCC develops in the basal cells that produce new skin cells as old ones die off. BCC is slow growing, painless, and can vary greatly in appearance—from a waxy raised bump to flat pale or red patches (Figure 2). BCC gradually destroys surrounding tissues and bone, yet it is the most easily treated skin cancer and rarely metastasizes to other areas of the body. However, when BCC grows near the eye, mouth, or nose, the results can be difficult to treat. Most BCCs are located on areas of the skin that are regularly exposed to the sun or UV radiation. Often a crusty or oozing lesion will appear that does not heal well and bleeds easily. People are at increased risk if they have light skin, hair, and eyes; had many severe sunburns as children; or experienced long-term exposure to the sun.³ Unfortunately, BCC has a high recurrence rate.

SQUAMOUS CELL CARCINOMA

SCC is located in the middle portion of the epidermis and occurs when squamous skin cells change due to regular exposure to sun and UV rays (Figure 3).⁴ SCC is relatively slow growing, but it spreads faster than BCC and can metastasize to other sites of the body. Most often seen in people over the age of 50, after years of sun exposure, SCC can occur anywhere on the body, including the inside of the mouth. SCC varies in appearance and is often mistaken for AK. Rarely does SCC cause further problems when detected early. However, when left untreated, SCC can grow deep into underlying tissues causing serious complications and disfiguration.

MELANOMA

Melanoma is the least common but most deadly type of skin cancer. Melanoma occurs in the melanocytes, the cells that produce skin pigment. The exact cause of melanoma is unclear, but genetics and prolonged exposure to the sun’s UV rays or tanning devices increase the risk. There are four stages of melanoma, ranging from early superficial lesions to those that have penetrated deeper into the tissues and involve lymph nodes. Melanoma is linked with advanced age, yet is increasingly associated with younger individuals—especially women between the ages of 15 years and 29 years who use indoor tanning devices.⁵ Melanoma may vary in appearance, but classically develops on the skin associated with a mole (Figure 4). Melanoma has been found in the iris of the eye and in the mouth. Unlike BCC and SCC, melanoma can spread quickly and has the high probability of metastasis, making it the most dangerous type of skin cancer.

NONSURGICAL TREATMENTS

Topical fluorouracil creams that interfere with DNA synthesis and cell proliferation are approved by the Food and Drug Administration (FDA) and may be used for AK and superficial BCC (sBCC) in low-risk areas.⁶ The cream is applied twice daily for 6 weeks and has a cure rate of approximately 80%.⁶ Topical fluorouracil is recommended only for superficial lesions due to its inability to penetrate deeply into the dermis of the skin.

Imiquimod (Aldara) is a topical cream that modifies the skin’s immune system to stimulate the body’s rejection of precancerous cells. Aldara is FDA approved for treatment of AK and sBCC. The topical cream is applied once daily for 6 weeks to 12 weeks and has a cure rate of 75% to 80%.⁷ The treatment is usually initiated three times per week and is increased to daily use. Patients using topical creams will experience mild to moderate skin irritation during treatment.

Radiation therapy (RT) involves the use of focused, high energy X-rays to destroy cancer cells. RT can be an option for patients with advanced disease or for those whom surgery is not an option. However, RT is contraindicated in young patients, individuals with connective tissue diseases or genetic conditions predisposed to skin cancer, and on lesions of the trunk and extremities due to the high risk of radiodermatitis and scaring.⁸

Photodynamic therapy (PDT) combines a drug that is activated by a specific type of light to kill cancer cells. PDT is administered orally or parenterally, as well as applied topically and localized into tumor cells before being activated by light exposure. The agent is absorbed by all cells in the body but is retained longer in atypical cells. After a period of time (hours to days), the target is exposed to wavelengths of light that trigger the medication. The photosensitizer in the cells absorbs the light and produces an active form of oxygen that destroys cancer cells. The increased energy is absorbed by adjacent tissue oxygen, causing the formation of singlet oxygen radicals. These radicals rapidly react with adjacent tissue and destroy it. PDT yields 50% cure rate for sBCC vs 83% cure rate for nodular BCC.⁹

SURGICAL TREATMENTS

Surgical options include complete removal of the lesion and a specialized technique called Mohs micrographic surgery (MMS). MMS is considered one of the best methods for treating BCC and SCC, especially on the face, because it achieves the lowest recurrence rate with maximal preservation of uninvolved skin.^10,11 Typically performed in an outpatient setting under local anesthesia by a team that includes a dermatologist, histotechnician, pathologist, and plastic surgeon, MMS is a specialized procedure in which a dermatologist excises the skin cancer at a 45° angle with subsequent identification of residual tumor using light microscopy. This technique is accomplished by dividing the specimen into small sections with different color dyes. The cancer cells are removed layer by layer and each layer is examined under the microscope until no abnormal cells remain. MMS allows total control of the surgical margins without guessing, which enables the entire lesion to be removed while preserving surrounding healthy tissue. Table 2 includes a list of indications for MMS.

RISK MANAGEMENT

Skin cancer is preventable and much can be done to mitigate its risk (Table 3).¹² The Skin Cancer Foundation recently released a cancer alert for drivers that recommends protecting the side of the body that faces the window and avoiding sunroofs and convertibles.¹³ Research suggests that skin cancers occur more often on the side of the body that faces the car window.¹⁴ Car windows provide no real protection from the sun’s harmful rays, and drivers’ head and neck areas are vulnerable. A study in the Journal of the American Academy of Dermatology revealed that nearly 53% of skin cancers in the United States occur on the left side of the body.¹⁴ Researchers believe the increase in lleft-sided skin cancers may be from UV exposure while driving.
On June 14, 2011, the FDA issued new

labeling requirements to help consumers identify products that are best at reducing the risk of skin cancer. Sunscreens that protect against both UVA (short-wave rays that cause tanning) and UVB (long-wave rays that cause sunburn) rays can be labeled broad spectrum. However, in order for products to claim they reduce the risk of skin cancer and protect against sunburn and early skin aging, they must have a sun protective factor (SPF) of 15 or higher. The FDA stated that sunscreens can no longer be called “sunblocks” as this implies “complete protection.” Products will no longer be allowed to claim “waterproof” or “sweat-proof” without FDA approval, but may claim to be water resistant for 40 minutes to 80 minutes.¹⁵ Recently, the Obama administration put pressure on the tanning salon industry with the passage of the new health care reform bill. Effective July 1, 2011, a 10% tanning tax will be imposed on customers using specific indoor tanning devices (those with one or more UV lamps with wavelengths between 200 nanometers and 400 nanometers). The American Academy of Dermatology supports the tanning tax because of the significant health risks associated with indoor tanning. This policy should serve as a warning to consumers that the use of tanning devices is dangerous. As Americans spend approximately $1.8 billion each year treating skin cancer, the tanning tax may help offset these significant costs.¹⁶

SCREENING IN THE OPERATORY

Dental professionals routinely perform extraoral examinations as part of an overall patient assessment. As such, they should be able to recognize potential problems and differentiate common types of skin cancers. Although skin cancers can appear differently from person to person, the A-B-C-D-E system of skin cancer identification is simple to use (Table 4).
Lesions that are dissimilar on one side, have irregular borders, or that change should be evaluated. Generally, if a lesion is suspicious or does not heal within 2 weeks, it should be examined by a dermatologist. Skin cancer may manifest anywhere on the body, but most often develops on the face, ears, head, neck, hands, and arms. Some skin cancers develop slowly, and it may take years to see evidence of a problem. If left untreated, cancer cells can spread and result in serious consequences. The fact that skin cancers come in all sizes, shapes, and colors is a solemn reminder of the importance of routine examinations using the cancer “alphabet” as a guide.

A diagnosis of skin cancer can be disconcerting, but dental professionals are in a unique position to educate patients about skin cancer prevention and detection. Skin cancers are on the rise, but most are preventable and treatable if detected early. As dental professionals, we need to advise patients to perform frequent self-examinations to identify new lesions and monitor suspicious areas for change using the skin cancer alphabet as a guide. Knowing the risk factors and warning signs will help reduce all types of skin cancers. As is the case with all cancers, prevention and early detection result in the best possible outcome.

BONUS WEB CONTENT

SKIN CANCER GETS PERSONAL

Author Gayle B. McCombs, RDH, MS Over the past few years I have endured five skin cancer surgeries, four of which were basal cell and one melanoma. The most recent lesions started as tiny, innocuous red spots on the bridge of my nose, first on one side, then the other. Nothing to worry about I thought, just two dry spots on my face that need more lotion. For weeks, I went through the ritual of liberally applying lotion to my nose and watching the red spots clear up and then reappear. After a few months, one of the red spots began to spontaneously bleed when I washed my face. I still thought it was nothing serious, only dry skin or a little ulceration that would eventually heal itself.

I did become concerned enough to make an appointment with a physician. My initial visits consisted of an examination and biopsies. When I returned for the biopsy results I could see the uneasiness on the physician’s face: it was not good news, basal cell carcinoma on both areas of my nose and melanoma on my arm, an area I had not even noticed until I had a full body examination.

The physician explained that the lesions on my nose needed to be removed and grafts placed over the sites, with the donor tissue coming from behind my ear or shoulder area. Furthermore, because of my history of excessive sun exposure, it might even be best to do a complete graft over my entire nose, “extension for prevention” as we used to call it in dentistry. The frightening prospect of having two grafts placed on my nose, or worse, having my entire nose tissue replaced was very unsettling.

I began to search the Internet about nose skin cancer and treatment options. After viewing several photos of nose surgeries, I came across a technique called Mohs Surgery. I felt that Mohs surgery offered a better option over grafting. I sought a second opinion and found a Mohs surgeon in my area—it was the best decision I made. I am fortunate that my community had a Mohs surgery team who worked together to ensure the best possible treatment and outcomes (Figures 1 and 2).

Editorial Director Jill Rethman, RDH, BA

Growing up, I was a sun worshipper. I lived during the heydays of “bronze is beautiful” when we’d bake in the sun all day with nothing to protect our skin but baby oil (not to prevent burning but to keep our skin moist so we could get as dark as possible). I never worried about skin cancer, though. This was the 70s and 80s and no one worried about skin cancer or aging from the sun. Besides, I’m Italian and I never burn…I thought I was safe. When tanning beds came along, I was one of their best customers.

In December 1995, I noticed a black mole that suddenly appeared on my inner right thigh. At first, I thought nothing about it. Then my dental hygiene instincts kicked in: why did this lesion seem to appear overnight? And why is it so dark? Although it was small (about a millimeter in diameter) my inner voice told me to get it checked out. When I went to my primary care physician, he told me to not worry about it—it was just a “little mole.” I insisted it be removed, after explaining to him that I was a dental hygienist and didn’t like how it looked. I am convinced that he removed it because he thought I was concerned about the esthetics of it, but in reality my gut was telling me to get rid of it.

About a week before Christmas, the physician called me with a very solemn tone in his voice. He told me that the “little mole” was melanoma. He was extremely apologetic and told me that “I was so wise to insist that it be removed.” At the time, we lived near Johns Hopkins so I was able to benefit from the excellent care and expertise offered at this world renowned facility. I had further removal of the surrounding tissue to make sure the melanoma had not spread beyond that small area on my leg. I was lucky—it had not. I had caught the lesion so early that no additional treatment was needed. Sixteen years later, I’m still melanoma-free. I have a 3-inch scar to remind me how fortunate I was. And although my sun days have been long over, I am so glad I listened to my dental hygiene instincts!

REFERENCES

1. Rogers, HW, Weinstock, MA, Harris, AR, et al. Incidence estimate of nonmelanoma skin cancer in the United States, 2006. Arch Dermatol. 2010;146:283-287.
2. Criscione VD, Weinstock MA, Naylor MF, Luque C, Eide MJ, Bingham SF. Actinic keratoses natural history and risk of malignant transformation in the Veterans Affairs Tropical Tretinoin Chemo-prevention Trial. Cancer. 2009;115:2523-2530.
3. Chinem VP, Miot HA. Epidemiology of basal cell carcinoma. An Bras Dermatol. 2011; 86:292-305.
4. Madan V, Lear JT, Szeimies RM. Nonmelanoma skin cancer. Lancet. 2010;375:673-685.
5. Lim HW, James WD, Rigel DS, Maloney ME, Spencer JM, Bhushan R. Adverse effects of ultraviolet radiation from the use of indoor tanning equipment: time to ban the tan. J Am Acad Dermatol. 2011;64:893-902.
6. Robins P, Gupta AK. The use of topical fluorouracil to treat actinic keratosis. Cutis. 2002;70(2 Suppl):4-7.
7. Garcia-Martin E, Idoipe M, Gil LM, et al. Efficacy and tolerability of imiquimod 5% cream to treat periocular basal cell carcinomas. J Ocul Pharmacol Ther. 2010;26:373-379.
8. Alam M, Nanda S, Mittal BB, Kim NA, Yoo S. The use of brachytherapy in the treatment of nonmelanoma skin cancer: A review. J Am Acad Dermatol. 2011 Apr 13. Epub ahead of print.
9. Calzavara-Pinton PG, Szeimies RM, Ortel B, Zane C. Photodynamic therapy with systemic administration of photosensitizers in dermatology. J Photochem Photobiol B. 1996;36:225-231.
10. Wood LD, Ammirati CT. An overview of mohs micrographic surgery for the treatment of basal cell carcinoma. Dermatol Clin. 2011;29:153-160.
11. Belkin D, Carucci JA. Mohs surgery for squamous cell carcinoma. Dermatol Clin. 2011;29:161-174.
12. Skin Cancer Foundation. Guidelines for Year Round Sun Protection. Available at: www.skincancer.org/year-round-sunprotection.html. Accessed June 27, 2011.
13. Skin Cancer Foundation. Sun Safety for Drivers. Available at: www.skincancer.org/sunsafety-for-drivers.html. Accessed June 27, 2011.
14. Butler ST, Fosko SW. Increased prevalence of left-sided skin cancers. J Am Acad Dermatol. 2010;63:1006-1010.
15. FDA Sheds Light on Sunscreen. Available at: www.fda.gov/ForConsumers/ConsumerUpdates/ucm258416.htm. Accessed June 28, 2011.
16. CNNMoney. Tanning Salons Burned by Health Care Bill. Available at: http://money.cnn.com/2010/03/24/news/economy/tanning_tax/index.htm. Accessed June 27, 2011.

From Dimensions of Dental Hygiene. July 2011; 9(7): 54-57.