Head and Neck Skin Cancer: Dentists’ Responsibility in Early Detection
While there are 35,000 diagnosed oral cancers per year and 7,500 deaths, there are 30 times this amount when it comes to cases of skin cancer, the majority of which are found on the head and neck. Because many patients see their dentist more frequently than their medical doctor, dentistry is in an advantageous position to reduce the mortality/morbidity of this most common malignancy. This article discusses various types of head and neck skin cancer and how dental practitioners can perform clinical examinations to provide early detection for patients.
Oral cancer examinations have been the standard of care in dentistry for many decades.1,2 A question arises as to whether or not dentists should also be performing head and neck skin cancer examinations. While there are 35,000 diagnosed oral cancers per year and 7,500 deaths,3 there are 30 times this amount when it comes to skin cancer—more than 1 million diagnosed skin cancers per year and 12,000 fatalities.4 Seven percent of skin cancers are life-threatening melanomas,5 and approximately 75% of all skin cancer deaths are from melanoma.6
The majority of skin cancers are found on the head and neck.7 The scope of this problem is significant, as one in five Americans will develop skin cancer.8 More than one person per hour dies from melanoma.9 Since 1994, non-melanoma skin cancer has increased more than 300%, and melanoma has doubled.10 Skin cancer accounts for 50% of all diagnosed cancers.11 Since many patients see their dentist more frequently than their medical doctor, dentistry is in a unique position to reduce the mortality/morbidity of this most common malignancy.12
As with all cancer, early detection is the key13; 99% of skin cancer patients survive with early detection.9 Metastasis and mortality, as well as surgical scarring and morbidity, are drastically reduced with early detection.13
So how should the clinical examination be performed and what should practitioners look for to achieve this early detection? The first part of the clinical examination is a visual screening of the skin on the head and neck to look for any suspicious lesions.14 The second part of the clinical examination is palpation. The palpation that clinicians are already performing for oral cancer can easily be extended to include the lymph nodes and skin lesions of the head and neck region.14 This should begin by palpating the submental area, proceeding to the three groups of nodes associated with the submandibular gland, then moving to the parotid gland and the pre- and post-auricular nodes. Next, the practitioner should continue posterior to the occipital nodes, looking for lymphadenopathy, which can be an indicator of skin or other cancers (lymphoma, metastatic oral cancer, etc.) (Figure 1). A patient who fits some or all of this profile is indicated for referral to a dermatologist.
Types of Skin Cancer
The three primary types of skin cancer include basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma.15 BCC and SCC are both slow-growing and relatively easy to treat.16 Melanoma can spread quickly and is relatively difficult to treat if it has already metastasized. If caught early, however, melanoma is highly curable.17
BCC begins in the basal cells of the skin. These basal cells produce new skin cells as old cells die. BCC typically starts as a pearly white or pink bump that bleeds easily. It can also look like a scar, mole, or scaly skin. BCC is four times more prevalent than SCC,18 and 80% of BCC is found on the head and neck.7 Three in 10 Caucasians develop BCC within their lifetime.19
An example of basal cell carcinoma (BCC) is shown in Figure 2. A 67-year-old man presented with a history of multiple sunburns as well as a family history of skin cancer, psoriasis, and chronic actinic keratosis. A pink, non-healing abrasion that bled easily for several weeks duration was noted (Figure 2). Review of systems for this patient was unremarkable. The dermatologist performed a shave biopsy of the lesion.20 The pathology report was positive for BCC. The patient was treated with a two-stage Mohs surgery and a microscopically controlled surgery; healing was uneventful.21
SCC typically starts as a tender pink bump with a central crater. SCC is twice as prevalent in males.22 The incidence of SCC increases with age and peaks at age 65.23 SCC of the lip and ear are at higher risk of metastasis than SCC on other areas of the skin.24
Figure 3 shows an example of squamous cell carcinoma (SCC). In this case, a 67-year-old woman presented with a pink papule with central ulceration on the left side of her nose. She reported that it started as a pimple 1 month previously and had grown quite rapidly (Figure 3). She denied any other risk factors for skin cancer. Review of systems for this patient was positive for type II diabetes and facial surgery. The dermatologist performed a shave biopsy of the lesion.20 The pathology report was positive for SCC. The patient was treated with a three-stage Mohs surgery. The significant wound healed by secondary intention, the process of healing a wound without the benefit of surgical closure.21 The patient’s recovery was unremarkable.
The most serious and dangerous form of skin cancer, melanoma develops in the melanocytes that produce melanin.25 If the skin receives excess ultraviolet (UV) light, the melanocytes may begin to grow abnormally, resulting in melanoma. This cancer is most often found in white males.22
Most melanomas manifest as a new lesion. One-third of cases, however, arise from a preexisting mole that converts to a melanoma.26 Many, but not all, show the ABCDE features: A = asymmetry; B = irregular borders; C = different colors; D = diameter of 6 mm; E = evolution, ie, a change in the existing mole27 (Figure 4). Note that a diameter of 6 mm is a soft guideline28; melanomas can be as small as 2 mm, and many moles greater than 6 mm are benign.
Patients who have had melanoma are at high risk for recurrence.25 Lesions suspicious for melanoma are often screened with a dermatoscope or confocal microscope, but biopsy is the only way to make a definitive diagnosis.29 Early diagnosis and treatment are very effective,28 while later diagnosis and treatment are much more difficult. Therefore, clinicians must be aggressive in their referrals to the dermatologist.
A clinical case of melanoma is shown in Figure 5. A 73-year-old woman presented with a 6-mm hyperpigmented macule on her right posterior neck. Note how well this macule (Figure 5) matched the danger signs of melanoma. The patient reported a past history of benign moles, and this current mole was changing color. Review of systems for this patient was unremarkable. The dermatologist performed a shave biopsy, which pathology reported was positive for superficial melanoma. The patient was treated by excision using blunt dissection through the dermis into the subcutaneous fat. This patient healed well because the melanoma was detected early.
Other Types of Skin Cancer
While the aforementioned types of skin cancer are the most common, there are other less prevalent types as well, including: Kaposi sarcoma (KS) (Figure 6), merkel cell carcinoma (MCC)30 (Figure 7), sebaceous gland carcinoma (SGC) (Figure 8), cutaneous T-cell lymphoma (CTCL) (Figure 9), dermatofibromasarcoma protruberans (DFSP) (Figure 10), and atypical fibroxanthoma (AFX) (Figure 11).
The general categories of benign lesions that must be included in the differential diagnosis include moles, cysts, and warts. Moles are the most common growths in humans.26 Their incidence peaks in adolescence. Moles generally begin as flat brown spots (Figure 12) similar to a freckle. These benign tumors come from melanocytes. Moles come in a variety of sizes, shapes, and colors.31 Some moles have the potential to become melanomas and, therefore, need to be monitored regularly.31
Epidermoid or sebaceous cysts are the most common type of skin cysts32 (Figure 13). The cyst is composed of epidermal cells that project into the dermis. A sebaceous cyst presents as a raised, round bump.1
Seborrheic keratosis is a dry, scaly wart-like growth on the surface of the skin, commonly seen after age 4033 (Figure 14). The growth is yellow, black, or brown, round, and slightly elevated with a “pasted-on” appearance, which often mimics melanoma.
Skin Cancer Risk Factors
Risk factors for skin cancer can be divided into patient genetics, past medical history, behaviors, and symptoms.34,35 Genetic risks include previous patient history or family history of skin cancer; patients with fair or depigmented skin (albinism, vitiligo), patients with dysplastic or atypical moles, and patients with multiple moles are all at increased risk.34,35 Patients with a medical history of radiation exposure, immuno-suppressive medications, or burns are also at an elevated risk.30
Personal behaviors that predispose a patient to skin cancer include tanning-bed use, tobacco use, multiple childhood sunburns, and migration to the Sun Belt states.31 Patient symptoms of concern include an area that does not heal (eg, a complaint such as having a cold sore for 2 months that won’t go away), areas that bleed easily, and new moles that look different than other moles.36 Lymphadenopathy (swollen glands) is also clearly a cause for concern.
Since 90% of skin cancers are associated with exposure to UV rays, protection is the key to patients preventing skin cancer.37 Clinicians can share with patients steps—some obvious, and some not so obvious—that can be taken, including:
• Avoid the sun between 10 a.m. and 4 p.m.38
• Wear UV-protected sunglasses and a hat with a 2-inch brim.38
• Wear protective clothing—which is much more effective than sunscreen38—such as long sleeves and clothing with an ultraviolet protection factor.
• Use a sunscreen that protects from UVA (ultraviolet A [longwave]) and UVB (ultraviolet B [shortwave]) rays with a sun protection factor (SPF) 30 or higher.39 SPF, however, only tells how effective a sunscreen is at protecting against UVB rays. Sunscreens also need to be effective against UVA rays. The active ingredients in sunscreen that protect against UVA rays are zinc oxide, titanium dioxide, helioplex, mexoryl, or avobenzone.40
• Reapply sunscreen every 2 hours on the face and especially the lips, as sunscreen rubs off with eating and talking.41
• Wear lip balms with SPF 30 (these are rare but can be found online).>
Fortunately, skin cancer, like dental pathology, is largely preventable. Head and neck skin cancer is a serious and growing problem. Dentists who look for it can help detect areas of suspicion, make appropriate referrals to dermatologists for further examination, and better serve their patients.
This article was originally published in the Journal of the Colorado Dental Association in April 2012, pp. 10-13, and was titled “Head and Neck Skin Cancer: Are We Missing the Forest Through the Trees?” It is reprinted with permission by the Colorado Dental Association. It has been edited to conform to Compendium style.
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seborrheic keratoses, cherry hemangiomas, and epidermoid cysts. American Academy of Dermatology. www.docstoc.com/docs/69717845/Common-Benign-Cutaneous-Growths--Seborrheic-Keratoses-Cherry. Accessed January 21, 2013.
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38. Can basal and squamous cell skin cancers be prevented? American Cancer Society. www.cancer.org/cancer/skincancer-basalandsquamouscell/detailedguide/skin-cancer-basal-and-squamous-cell-prevention. Accessed January 21, 2013.
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41. Essential sun safety information for skiers & snowboarders. The Skin Cancer Foundation. www.skincancer.org/healthy-lifestyle/outdoor-activities/essential-sun-safety-information-for-skiers-and-snowboarders. Accessed January 21, 2013.
A CE article, Dental Oncology: Caring for Individuals Battling Cancer, is available from CDEWorld at dentalaegis.com/go/cced339
About the Authors
Paul Corcoran, DDS
Louis Depaola, DDS, MS
Professor and Chairman of Oncology and Diagnostic Sciences
University of Maryland Dental School
Karen Nern, MD
Jean Urquhart, MD