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Wernli KJ, Henrikson NB, Morrison CC, et al. Screening for Skin Cancer in Adults: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2016 Jul. (Evidence Syntheses, No. 137.)
This publication is provided for historical reference only and the information may be out of date.
Screening for Skin Cancer in Adults: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force [Internet].
Show detailsScope and Purpose
This report will be used by the U.S. Preventive Services Task Force (USPSTF) to update the prior review of the effectiveness of skin cancer screening in average-risk persons. In 2009, the USPSTF concluded there was insufficient evidence to assess the balance of benefits and harms of screening for skin cancer by primary care clinicians or by patient skin self-examination (I statement).1
Condition Definition
Skin cancer is among the most common cancers in men and women in the United States.2 Skin cancer is classified as: 1) nonmelanoma skin cancer (NMSC), which includes basal cell and squamous cell cancers, and 2) melanoma skin cancer. NMSC represents the vast majority of skin cancers (>97%) and has very low mortality.2 Melanoma skin cancer is less common than NMSC but has a higher mortality and case-fatality rate.3 Detection of melanoma is the primary focus of skin cancer screening.
Prevalence and Burden
NMSC
Because NMSC is not a reportable cancer to the Surveillance, Epidemiology, and End Results Program (SEER) or state cancer registries, population estimates are based on care visits or skin procedures. An estimated 4.3 million cases of NMSC were treated in the United States based on U.S. and Australian population statistics.4 The incidence of NMSC increases with age5-7 and is more common in men than in women.5, 7 Among the Medicare-eligible population, approximately 2.1 million men and women are diagnosed with NMSC annually.8 With the increasing use of tanning beds, there is growing concern about skin cancer in younger populations. The estimated age-adjusted incidence of basal cell carcinoma in persons younger than age 40 years in Olmsted County, Minnesota is 25.9 cases per 100,000 women and 20.9 cases per 100,000 men.9 The incidence of squamous cell carcinoma in the same population was similar between men and women at 3.9 cases per 100,000 persons.9
The overall incidence of NMSC appears to be increasing over the past few decades; however, this observation could be the result of more evaluations and skin biopsies, leading to more diagnoses rather than a true increase in disease in the population.10
Mortality statistics are difficult to determine for NMSC but suggest that the case-fatality rate from NMSC is quite low.10 From the state of Rhode Island, the age-adjusted NMSC mortality rate is estimated at 0.91 deaths per 100,000 person-years among residents.11 While mortality is low, the enduring impact of NMSC is reflected in the high recurrence rate of approximately 50 percent.12
Melanoma
Malignant melanoma is the fifth- and seventh-leading cancer diagnosed in men and women, respectively.13 In 2015, an estimated 73,870 persons were diagnosed with melanoma in the United States and 9,940 persons died from the disease.13 Over the past nearly 40 years, melanoma incidence rates have increased and mortality rates have remained relatively stable. The increase in melanoma incidence is in part attributed to an increase in skin biopsies, which increased 2.5-fold in the SEER-Medicare population from 1986 to 2001.14 Additional biopsies have resulted in increases in the number of early-stage melanoma cases detected, mainly melanoma in situ.14
Melanoma Incidence
From 1975 to 2011, age-adjusted melanoma incidence rates increased 3-fold from 7.9 to 22.7 new cases per 100,000 persons.3
Age
Melanoma incidence increases with age. During 2007 to 2011, among persons younger than age 65 years, the incidence rate was 12.7 cases per 100,000 persons compared to 81.1 cases per 100,000 persons age 65 years and older.3
Sex
The age-adjusted melanoma incidence rate was higher in men than in women during 2007 to 2011, with 27.7 cases per 100,000 men versus 16.7 cases per 100,000 women.3 However, this pattern is not consistent across all ages. Younger women, from teens to adults younger than age 50 years, have higher incidence rates than men.3
Race
Melanoma incidence varies by race. The age-adjusted melanoma incidence rate was 25.2 cases per 100,000 whites compared to 1.0 case per 100,000 blacks during 2007 to 2011.3
Stage
For cases diagnosed from 2004 to 2010, the distribution of stage at diagnosis was 84 percent localized, 9 percent regional, 4 percent distant, and 4 percent unstaged.3
Melanoma Mortality and Survival
From 1975 to 2011, age-adjusted melanoma mortality rates increased slightly from 2.1 to 2.7 deaths per 100,000 persons.3 Five-year relative survival among persons diagnosed during 2002 to 2009 was 93% overall.3
Age
Melanoma mortality rates increase with age. During 2007 to 2011, among persons younger than age 65 years, the mortality rate was 1.2 deaths per 100,000 persons compared to 13.4 deaths per 100,000 persons age 65 years and older.3
Sex
Age-adjusted melanoma mortality rates are higher in men than in women at 4.1 versus 1.7 deaths per 100,000 men and women, respectively, during 2007 to 2011.3 Five-year relative survival was 91.1 percent in men and 95.0 percent in women among cases diagnosed during 2004 to 2010.3
Race
Melanoma mortality rates are greater in whites than in blacks. During 2007 to 2011, the age-adjusted melanoma mortality rate was 3.1 deaths per 100,000 whites compared to 0.4 deaths per 100,000 blacks.3 However, 5-year relative survival among persons diagnosed during 2004 to 2011 was lower in blacks (75.1%) than in whites (92.9%).3 This difference in relative survival according to race has been attributed to a difference in the distribution of stage at diagnosis: among those diagnosed in 2004 to 2010, 19 percent of blacks were diagnosed with distant or unknown stage of disease compared to only 7 percent of whites.3
Stage
For people diagnosed from 2004 to 2010, 5-year relative survival by stage was 98.1 percent for localized, 62.6 percent for regional, 16.1 percent for distant, and 78.3 percent for unstaged disease at diagnosis.3 The vertical depth of melanoma is one of the strongest predictors of patient survival. Fifteen-year patient survival is 93 percent for depth less than 1 mm, 68 percent for depth 1 to 4 mm, and 42 percent for depth greater than 4 mm.15
Etiology and Natural History
NMSC
NMSC arises from keratinocytes or their precursors.10 Basal cell carcinoma arises in the lower layers of the epidermis. Squamous cell carcinoma arises in the mid-layer of the epidermis, and can become invasive if left untreated. Actinic keratosis is thought to be the precursor lesion to squamous cell carcinoma and tends to occur in persons with fair skin and blond or red hair.2
Ultraviolet radiation from sun exposure or artificial sources damages DNA and leads to carcinogenesis of both basal and squamous cells.16
Melanoma
Like all cancers, melanoma is described as a process of unregulated clonal growth.17 Typically, melanocytes are found in the border of the epidermis and dermis layer. Melanocytes that grow in a horizontal lentiginuous pattern appear on the skin as a freckle. Clusters of melanocytes can form to develop nevi. Mutations can result in nevi with pleomorphic features (i.e., variable cell and nuclei sizes and shapes) that have the potential to leave the epidermal border to locate in other areas of the skin.17 The two most common types of melanoma are superficial spreading and nodular melanoma. The vertical depth of the melanoma is directly associated with prognosis. The common locations for melanoma to occur vary in men and women. In men, melanoma is more common on the back and in the head and neck areas. In women, melanoma is more common in the lower extremities, in particular, below the knee.18
Risk Factors
Risk factors for melanoma and NMSC are similar, although there are some risk factors that are mainly associated with melanoma risk.
Melanoma Only
Risk factors for melanoma are summarized in a recent meta-analysis of observational studies.19-21
Family History of Melanoma
Pooled estimates suggest a 74 percent increased risk of melanoma with family history of the disease (relative risk [RR], 1.7 [95% confidence interval (CI), 1.4 to 2.1]).21
Dysplastic Nevi
Increased total number of dysplastic nevi is associated with a 6.4-fold increased risk of melanoma (comparing 5 vs. 0 dysplastic nevi: RR, 6.4 [95% CI, 3.8 to 10.3]).19
Multiple Nevi
The presence of 101 to 120 nevi compared to fewer than 15 nevi is associated with a 6.9-fold increased risk of melanoma (RR, 6.9 [95% CI, 4.6 to 10.3]).19
Sun Sensitivity
Having skin that sunburns easily is associated with a 2-fold increased risk of melanoma compared to having skin that never burns (RR, 2.1 [95% CI, 1.7 to 2.6]).21 Having natural red hair is associated with a 3.6-fold (RR, 3.6 [95% CI, 2.6 to 5.4]) increased risk of melanoma and natural blond hair is associated with a 2-fold (RR, 2.0 [95% CI, 1.4 to 2.7]) increased risk compared to having natural dark hair.21
History of Sunburns
Sunburn history in the highest frequency category is associated with a 2-fold increased risk of melanoma (RR, 2.0 [95% CI, 1.7 to 2.4]).20
Indoor Tanning
Ever use of tanning beds is associated with a 1.2-fold increased risk of melanoma (RR, 1.2 [95% CI, 1.0 to 1.3)22 and first use before age 35 years is associated with a 1.8-fold increase in risk (RR, 1.8 [95% CI, 1.4 to 2.3]).23
History of NMSC
A previous history of actinic keratosis or basal cell or squamous cell carcinoma is associated with a 4.3-fold increased risk of developing melanoma (RR, 4.3 [95% CI, 2.8 to 6.6]).21
NMSC
Risks of developing basal cell and squamous cell carcinoma increase with exposure to ultraviolet radiation, either through sun exposure or use of indoor tanning beds. Similar to melanoma risk, persons who sunburn easily,24-26 have natural red or blond hair,24-26 have sustained a greater frequency of sunburns,27 and have used indoor tanning beds22, 28 are at increased risk of developing basal cell and squamous cell carcinoma.
Rationale for Screening
The primary purpose of screening is to detect skin cancers earlier in their clinical course than would happen in usual care, allowing earlier and more effective treatment and thereby leading to a reduction in skin cancer morbidity and mortality.
Screening Strategies
Visual skin cancer screening is either a whole or partial body skin examination conducted by a primary care provider or dermatologist. Visual skin cancer screening strategies are focused on the detection of melanoma but can also detect NMSC.
Visual inspection is guided by either the ABCDE mnemonic or the ugly duckling perspective. The ABCDE mnemonic29 is an acronym of characteristics to detect melanoma: A) asymmetry (one half of nevus does not match the other half); B) border irregularity (edges of nevus are ragged, notched, or blurred); C) color (pigmentation of the nevus is not uniform, with variable degrees of tan, brown, or black); D) diameter greater than 6 mm; and E) evolving (nevus is changing over time). The ugly duckling approach assesses which nevus does not look like the others within a cluster of nevi.30
In addition to visual inspection of the skin, dermatologists often use a dermascope, a magnifying device, to further inspect the lesion or possibly whole body photography to assess changes in lesions.
Our review focused on clinical visual skin cancer screening by primary care or dermatology and distinct from skin self-examination, as conducted by the patient or partner.
Treatment Approaches
Prevention/Intervention
Primary prevention of skin cancer focuses on reducing exposure to sun or ultraviolet radiation exposure. Within primary care, physicians can be effective in counseling patients to avoid sun exposure and tanning beds and provide education on skin cancer risk factors.31, 32 In an effort to reduce additional ultraviolet radiation exposure in adolescents, several U.S. states have initiated legislation to ban the use of tanning beds in persons younger than age 18 years.33
Treatment
Definitive diagnosis of both NMSC and melanoma is through biopsy, including: 1) shave biopsy, 2) punch biopsy, or 3) excisional biopsy. The treatment options vary depending on the type of skin cancer.
NMSC
NMSC are removed by either surgical excision, Mohs micrographic surgery (i.e., tissue is removed in layers until microscopic examination of the layers indicates that the cancer has been completely removed), electrodessication and curettage (i.e., tissue destruction by electric current and removal by scraping with a curette), or cryosurgery (i.e., tissue destruction by freezing).2 Radiation therapy and certain topical medications might be also be used.2
Melanoma
Primary tumor and surrounding normal tissue are removed and sometimes a sentinel lymph node is biopsied to determine stage.18 There can be more extensive surgery if the sentinel lymph node is positive.18 Melanomas with deep invasion or that have spread to lymph nodes might also be treated with immunotherapy, radiation therapy, chemotherapy, or a combination.18 Advanced lesion thickness or later-stage melanoma cases may be treated with palliative surgery, immunotherapy, radiation therapy, chemotherapy, or a combination.18
Current Clinical Practice in the United States
Dermatologists tend to perform more skin screening examinations than family practice physicians or internists34 but lack the capacity to offer population screening.35 Potentially, to achieve skin screening of the general population, a two-step screening method with initial review of skin lesions in primary care and referral to dermatology for second review would be implemented. However, most primary care and general internists report not having sufficient training in skin cancer screening to feel confident in their skills to conduct whole body skin examinations on their patients.36 Hence, skin cancer screening in the United States among primary care physicians remains quite low. Primary care physicians in two counties in Connecticut and Florida indicate that only 31 percent perform skin cancer screening on their adult patients. The primary barrier to screening was the physician's lack of confidence in identifying a suspected lesion.37 While there are several educational interventions to improve knowledge of and confidence in skin cancer screening in primary care, few tools have been rigorously tested for measured changes in clinical practice.38
Currently, no U.S. professional organizations recommend clinician-performed skin cancer screening, including the American Academy of Family Physicians,39 American College of Preventive Medicine,40 American Academy of Dermatology (AAD),41 and the American College of Physicians.42 The American Academy of Family Physicians cites the 2009 USPSTF report43 as the basis for its conclusion that there is insufficient evidence to evaluate the balance of benefits and harms of screening.39 The American College of Preventive Medicine, AAD, and American College of Physicians do not have current guidance on whether or not to screen. The American Cancer Society has no specific recommendation for skin cancer screening, other than that persons age 21 years and older have a cancer-related checkup at their periodic health examination, including possibly an examination for skin cancer.44 The recommendations from the Community Preventive Services Task Force focus on preventing skin cancer through various educational and policy approaches, such as promoting individual behaviors toward sun protection, and target populations in child-care centers, outdoor occupational settings, or primary and middle schools.45
Despite no current screening guidelines, AAD41 has offered free skin cancer screening clinics since 1985, similar to its contemporary SPOTMe® screening campaign,46 and conducted 2.4 million screenings to date.
Previous USPSTF Recommendations
In 2009, the USPSTF concluded that the current evidence is insufficient to assess the balance of benefits and harms of screening the adult general population by primary care clinicians or by patient skin self-examination for early detection of cutaneous melanoma, basal cell skin cancer, or squamous cell skin cancer (I statement).43 The 2009 review found a lack of evidence about the influence of early detection on skin cancer mortality and morbidity and about the magnitude of harms from skin cancer screening.
The 2009 recommendation echoed findings from 2001, in which the USPSTF also concluded there was insufficient evidence to recommend for or against routine skin cancer screening by whole body skin examination for early detection of cutaneous melanoma, basal cell skin cancer, or squamous cell skin cancer (I statement).1
- Introduction - Screening for Skin Cancer in AdultsIntroduction - Screening for Skin Cancer in Adults
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