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PREVENTATIVE
MEDICINE

Skin Cancer Prevention

By Fatima Raza OMS-III, Faraz Yousefian, DO and Daniel Fischer, DO

S kin cancer is the most common cancer in the United States, fol- the more important. The American Academy of Dermatology has pub-
In the absence of routine screening, preventive measures become all
lowed by lung cancer, prostate cancer and breast cancer. Ac-
cording to American Academy of Dermatology estimates, one
shade particularly between the hours of 10 am and 2 pm, wearing sun-
in five Americans will develop skin cancer in their lifetime, and approx- lished multiple guidelines regarding skin cancer prevention: seeking
imately 9,500 people in the United States are diagnosed with skin can- protective clothing and using broad-spectrum, water-resistant sun-
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cer every day. In Texas, the odds are even more grim: the state ranks screen with SPF 30 or higher, reapplying every two hours. The AAD
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third in the nation for incidence of malignant melanoma, with 5,020 additionally recommends regular skin self-exams to detect cancer early.
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cases projected to be diagnosed in 2022. In the United States, skin In short, these guidelines essentially encourage patients to become their
cancer represents 20-30% of all neoplasms in Caucasians, 2-4% in own healthcare advocates.
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Asians and 1-2% in the Black population. Perhaps the bedrock of skin cancer prevention is the regular use of
Of the types of skin cancer, non-melanomatous skin cancers sunscreen. While most of the population may at least be aware that
(NMSCs), namely basal and squamous cell carcinomas, are the most sunscreen is protective in some form, the wide varieties and types of
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commonly diagnosed. Both of these cancers have overlapping risk fac- sunscreens may overwhelm the common consumer. Sunscreens are
tors, including tanning bed usage and ionizing radiation. However, the largely organized into two categories based on active ingredients: or-
most significant risk factor is UV radiation, principally UVB radiation ganic (physical) and inorganic (chemical). Organic filters include active
from sunlight exposure. In particular, occupational UVB exposure, as ingredients such as oxybenzone, while inorganic filters include titanium
in the agricultural and construction industries, is a major risk factor as dioxide and zinc oxide. Organic filters, however, have shown in some
compared to nonoccupational risk factors. UVB radiation is thought studies to have systemic effects in subjects including hormonal imbal-
to be more carcinogenic than UVA radiation due to its complete ab- ance. In addition, negative environmental impacts of the active ingre-
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sorbance by skin and resultant increased ability to mutate tumor sup- dients may potentially concern consumers. Inorganic sunscreen filters
pressor genes. Of the tumor suppressor mutations resulting in skin are considered alternatives to organic filters, and are present in sun-
cancer, p53 is the most common, with mutations found in up to 50% screens at sizes of <100nm. This size difference is cosmetically prefer-
of basal cell carcinomas. able to consumers, as the sunscreen is much less visible on the skin.
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While the risk factors and pathogenesis of skin cancers are well stud- Based on currently available data, inorganic filters are less harmful to
ied, there remains no consensus on screening guidelines for skin cancer. the environment and pose minimal health risk due to low levels of ab-
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The USPTF has not published screening recommendations, citing in- sorption across the skin barrier. While as of yet, there is no clear con-
sufficient evidence for its benefit. Diagnosis of skin cancers is therefore sensus as to which type of sunscreen provides superior UV protection,
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heavily reliant on clinical examination of the skin lesion. Clinical di- empowering patients with information about sunscreen choices as well
agnosis of NMSCs commonly includes aspects of patient history, in- as education on how and when to apply sunscreen may improve patient
cluding raised lesions which bleed and crust. Dermatoscopic evaluation initiative and participation in skin care and prevention.
and biopsy can often aid with clinical diagnosis. In melanomatous dis- The utility of preventive methods such as sunscreen, however, is lim-
ease, the importance of early clinical recognition and diagnosis is para- ited by other aspects of dermatologic care, such as physician constraints.
mount, as the cancer grows first horizontally and then vertically in A 2011 survey of primary care providers, internists and dermatologists
stages, with stage correlating to depth. In 1985, researchers at NYU reported that of all responding physicians, time constraints, competing
implemented the acronym ABCD, now commonly used in practice − comorbidities and patient embarrassment or reluctance were reported
A (asymmetry), B (border irregularity), C (color variegation), D (di- as the top three major barriers to performing full body skin examinations
ameter >6mm) and E (evolving or changing) for clinical diagnosis of on patients; these factors varied by specialty. Family physicians responded
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melanoma. with time constraints as the primary hindrance, while dermatologists re-

18 SAN ANTONIO MEDICINE • June 2022