Draft Recommendation Statement
Skin Cancer: Screening
November 30, 2015
Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
Skin cancer includes melanoma and basal and squamous cell carcinoma. Basal and squamous cell carcinoma, known together as nonmelanoma skin cancer, are the most commonly occurring types of cancer in the United States and represent the vast majority of all cases of skin cancer (>97%).1 However, nonmelanoma skin cancer rarely results in death or substantial morbidity, whereas melanoma skin cancer has notably higher mortality rates.1 For this reason, the USPSTF prioritized screening outcomes related to melanoma in developing this recommendation statement. In 2015, an estimated 74,000 U.S. men and women will develop melanoma and 9,940 will die from the disease.1
There is adequate evidence that visual skin examination by clinicians has modest sensitivity and specificity for detecting melanoma.
Benefits of Early Detection and Treatment
The evidence is insufficient to reliably conclude that early detection of skin cancer through visual examination by a clinician reduces morbidity or mortality.
Harms of Early Detection and Treatment
There is adequate evidence that visual skin cancer screening by a clinician leads to harms that are at least small, but current data are insufficient to precisely bound the magnitude of these harms. Potential harms of skin cancer screening include misdiagnosis and overdiagnosis and the resulting cosmetic and—more rarely—functional adverse effects resulting from biopsy and overtreatment.
The USPSTF concludes that the current evidence is insufficient and that the balance of benefit and harms of visual skin examination by a clinician to screen for skin cancer in asymptomatic adults cannot be determined.
Patient Population Under Consideration
This recommendation applies to asymptomatic adults who do not have a history of premalignant or malignant skin lesions. Patients who present with a suspicious skin lesion or who are already under surveillance because of a high risk of skin cancer, such as those with a familial syndrome (e.g., familial atypical mole and melanoma syndrome), are outside the scope of this recommendation statement.
Assessment of Risk
Skin cancer of any type occurs more commonly in men than women and among persons with a fair complexion, those who use indoor tanning beds, or those with a history of sunburns or previous skin cancer. Risk factors for melanoma include having a dysplastic nevus (atypical mole), multiple (i.e., ≥100) nevi, and a family history of melanoma.2 Like most cancers, the risk of melanoma increases with age; the median age at diagnosis is 63 years, and the median age at death is 69 years.1
Suggestions for Practice Regarding the I Statement
Potential Benefit of Early Detection and Treatment
Direct evidence to assess the effect of a clinical visual skin cancer screening examination on the risk of death from melanoma is limited.2 A single ecologic study (Skin Cancer Research to Provide Evidence for Effectiveness of Screening in Northern Germany [SCREEN]) with important methodologic limitations suggests that the benefit of a general population-based screening program combined with a disease awareness campaign may be, at most, 1 fewer melanoma death per 100,000 persons screened over a decade.3
Potential Harms of Early Detection and Treatment
Information on the harms of screening is also sparse.2 The majority of suspicious skin lesions identified during screening are not actually melanoma; depending on the age of the patient, the SCREEN study found that between 20 and 55 excisions were performed to detect 1 case of melanoma.4 The number of excisions required to prevent 1 melanoma death was not provided in the SCREEN study but can be estimated at more than 4,000. Overdiagnosis and overtreatment—the diagnosis and treatment of a cancer that would never have harmed the patient in the absence of screening—are other important potential harms. Ecologic evidence strongly suggests that visual skin screening results in the overdiagnosis of skin cancer;5, 6 however, current evidence is insufficient to be reliably certain of the magnitude of this effect.
Contemporary data on clinician practice patterns related to skin cancer screening appear to be limited. A 2005 survey of U.S. physicians found that 81 percent of dermatologists, 60 percent of primary care physicians, and 56 percent of internists reported performing a full-body visual skin cancer screening examination on their adult patients.7
The clinical visual skin cancer screening examination assesses skin lesions using the “ABCDE” rule, which involves looking for the following characteristics: Asymmetry, Border irregularity, nonuniform Color, Diameter greater than 6 mm, and Evolving over time.
The optimal interval for a visual skin cancer screening examination by a clinician, if one exists, is unknown.
Treatment of screen-detected melanoma generally involves excision with or without lymph node management, depending on the stage at diagnosis.
Other Approaches to Prevention
The USPSTF recommends that children, adolescents, and young adults ages 10 to 24 years who have fair skin be counseled about minimizing their exposure to ultraviolet radiation to reduce their risk of developing skin cancer (www.uspreventiveservicestaskforce.org).
The Community Preventive Services Task Force has made a number of recommendations related to preventing skin cancer through the use of interventions that target child care centers; outdoor occupational, recreational, and tourism settings; primary and middle schools; and communities (www.thecommunityguide.org/cancer/index.html).
Research Needs and Gaps
The USPSTF recognizes the challenge of conducting a definitive randomized, controlled trial (RCT) on primary screening with cause-specific mortality as an endpoint to provide clear evidence on the principal question of the efficacy of the clinical visual skin cancer screening examination, given the comparatively low rate of death from melanoma in the population (even among persons at higher risk). If adequately powered RCTs are not possible, a high-quality case-control study could overcome the issue of requiring a large sample size to ensure sufficient power. However, this study design has limitations in terms of the ability to create an appropriate comparison group, the ability to accurately measure the exposure of interest due to recall bias and other sources of misclassification, healthy volunteer bias (persons performing skin examinations likely have other good health habits), and other unmeasured sources of confounding. Studies would have to be carefully designed to avoid these threats to validity. Despite these challenges, the USPSTF concludes that further evidence is in fact necessary to advance the field on this essential question. An optimized version of the SCREEN study (i.e., a time series study), in which the clinical visual skin examination alone, without the potential confounding of a second intervention, is evaluated, would also be useful. Additional research on the possible harms of skin cancer screening—particularly the potential for overdiagnosis and overtreatment—is also needed to help fully understand the ultimate net benefit of the clinical visual skin examination.
Scope of Review
The USPSTF commissioned a systematic evidence review to update its 2009 recommendation on screening for skin cancer. The review addressed several questions about clinical visual skin cancer screening, including its effectiveness in reducing skin cancer morbidity and mortality and death from any cause; its potential harms, as well as any harms resulting from associated diagnostic followup; its test characteristics, when performed by primary care clinicians versus dermatologists; and whether its use leads to earlier detection of skin cancer compared with usual care.2 Unlike the previous review, the evidence concerning patient self-examination for skin cancer was not included, as the mission of the USPSTF is to provide guidance to clinicians about the preventive services they offer in the primary care setting; as such, patient visual self-examination was determined to be out of scope for this review (information about clinicians teaching patients how to perform a visual self-examination can be found in the “Update of Previous USPSTF Recommendation” section).
Accuracy of Screening Tests
A systematic review of 11 studies on the diagnostic accuracy of screening by primary care physicians and dermatologists identified during the previous evidence review found that screening by primary care clinicians had a sensitivity of 42 to 100 percent and a specificity of 98 percent in the diagnosis of melanoma.8 Since then, two additional studies on the test characteristics of the clinical visual skin cancer screening examination have been published—one evaluating primary care physicians and one evaluating dermatologists or plastic surgeons. These studies found that sensitivity ranged from 40 to 70 percent, which sharply decreased as the length of followup increased (from 12 to 24 or 36 months). Specificity ranged from 86 to 98 percent.2, 9, 10 None of the studies could draw reliable conclusions as to whether any of the clinical specialties differed in diagnostic accuracy.2, 8-10
Effectiveness of Early Detection and Treatment
No RCT has directly evaluated the effectiveness of the clinical visual skin cancer screening examination in reducing skin cancer morbidity or mortality (a pilot study in Queensland, Australia by Aitken et al began in 2002, but a full trial was never completed).2 A single fair-quality ecologic study (SCREEN) compared trends in melanoma mortality rates in one region of Germany using a population-based skin cancer awareness campaign, provider education and training, and clinical visual skin cancer screening program with several surrounding regions that did not have similar interventions available. After a 2-year period of public skin cancer awareness campaigns, 360,288 adults age 20 years and older (about 19% of the eligible population) received a clinical visual skin examination. After 10 years, the study found a 48 percent relative reduction in the risk of dying of melanoma in the region that instituted the interventions compared with the control regions, which translates into an absolute reduction of 1 fewer death from melanoma per 100,000 persons screened.11
The SCREEN study has several important limitations. First, it does not provide individual patient-level data on the impact of the visual skin cancer screening examination, and as an ecologic observational study, it is subject to the potential effects of known and unknown biases and confounders. Second, the separate effects of the public education element cannot be disentangled from those of the clinical visual skin examination component; therefore, it is likely that the effect of screening alone is smaller than estimated. In addition, the melanoma mortality rate in the region receiving the interventions was already declining prior to the introduction of the clinical visual skin examination program. This also suggests that the 48 percent relative reduction overestimates the true effect size of screening. Two other data points raise questions as to the plausibility of the observed effect: 1) only 19 percent of the total eligible population was actually screened, and 37 percent of these individuals were lost to followup, yet the relative magnitude of the mortality reduction in the population is larger than almost any other cancer screening intervention currently available; and 2) three fourths of the population screened were women, and yet, equal melanoma mortality reductions were observed among men and women.11
When direct, overarching evidence is inconclusive concerning the benefit of a screening intervention on health outcomes, the USPSTF also looks to a chain of indirect evidence to try to assess the effectiveness of the preventive service. In the case of the clinical visual skin cancer examination, this includes linking together information about the ability of screening to detect melanoma earlier than usual care and the association between earlier detection of skin cancer and resultant morbidity and mortality. The USPSTF identified only one single, fair-quality case-control study that pertained to the question of whether clinical visual skin cancer screening leads to the earlier detection of melanoma compared with usual care.2 It found a modest association between the clinical visual skin examination and early detection (odds ratio, 0.84 [95% confidence interval, 0.75 to 0.98]).12 Because the study used patient self-report to identify exposure to clinician skin examination, recall bias is a potential concern.
Harms of Early Detection and Treatment
Evidence on the harms of the clinical visual skin cancer examination is limited.2 In the SCREEN study, approximately 4.4 percent of screened individuals (or 1 in every 23 participants) underwent a skin excision for a suspicious lesion. The majority of these biopsies did not result in a cancer diagnosis. Overall, for both men and women, 1 case of melanoma was detected per 28 excisions performed. However, this varied greatly by age. For example, among men ages 20 to 34 years versus 65 years and older, 1 case of melanoma was detected per 52 versus 20 skin excisions, respectively.4
Cosmetic or, more rarely, functional adverse effects may also result from an excisional biopsy prompted by clinical visual skin examination, although there are few data available on the frequency or specific details of these events. One fair-quality study of a single physician’s performance of skin cancer screening and razor-blade shave biopsy among patients who were not ultimately diagnosed with skin cancer found that 7 percent of these patients expressed poor satisfaction with the cosmetic results (whereas the physician felt the results were poor in 16% of cases).2, 13
Overdiagnosis and overtreatment—the identification and treatment of a skin cancer that would never have harmed an individual—is also a potential outcome that is of concern. It is not possible to directly determine for any individual patient whether a diagnosed cancer will progress or not; as such, measuring overdiagnosis is not a straightforward process and must be indirectly quantified. In the case of skin cancer, limited research has been done to estimate the potential magnitude of the burden of overdiagnosis associated with screening. An ecologic study linking melanoma incidence and mortality data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program to Medicare claims for skin biopsy among patients age 65 years and older found that from 1986 to 2001, the average incidence of melanoma increased 2.4 times (from 45 to 108 cases per 100,000 persons), while the average biopsy rate increased 2.5 times (from 2,847 to 7,222 biopsies performed per 100,000 persons). However, the increased cancer incidence was entirely due to extra cases of in situ and local disease, without the expected complementary decrease in the incidence of advanced melanoma or melanoma mortality. The authors concluded that this pattern strongly suggested that screening efforts in the United States were generating overdiagnosis, rather than depicting a true increase in the occurrence of melanoma.5
Estimate of Magnitude of Net Benefit
Evidence to assess the net benefit of the clinical visual skin cancer screening examination is limited. Direct evidence on the effectiveness of screening in reducing melanoma morbidity and mortality is limited to a single fair-quality ecologic study with important methodologic limitations. It suggests that, at best, a program of public education and disease awareness coupled with visual skin cancer screening by a clinician may reduce the risk of dying from melanoma among average-risk adults by about 1 death per 100,000 persons screened over 10 years; however, there are reasons to believe that the effect size is likely smaller. The indirect pathway of evidence (i.e., examining the association between visual skin cancer screening and earlier detection of melanoma [e.g., lesion thickness], and the association between earlier detection of melanoma and skin cancer–related morbidity and mortality) and the studies included as part of this pathway are subject to several important biases of screening, including lead-time bias and length-biased sampling. These biases preclude the USPSTF’s ability to draw reliable conclusions about the efficacy of the clinical visual skin examination with reasonable certainty. Therefore, there is insufficient evidence to reliably conclude whether a clinical visual skin cancer screening examination reduces melanoma morbidity or mortality. Information on harms is similarly sparse. The potential for harm clearly exists, including a high rate of unnecessary biopsies, possibly resulting in cosmetic or—more rarely—functional adverse effects, and the risk of overdiagnosis and overtreatment. It is difficult for the USPSTF to accurately bound the magnitude of these potential harms without better information about the frequency with which skin cancer is likely overdiagnosed and overtreated. Further, it is challenging for the USPSTF to correctly bound the magnitude of the net benefit without more accurate and precise information about the size of the potential mortality benefit, if one exists. As such, the USPSTF concludes that the evidence is insufficient to assess the balance of benefit and harms of visual skin cancer screening in adults.
This recommendation updates the 2009 USPSTF recommendation. The USPSTF has again concluded that the current evidence is insufficient to assess the balance of benefit and harms of a clinical visual skin cancer screening examination in adults. However, the USPSTF decided to no longer include a statement about patient skin self-examination in the updated recommendation statement. The mission of the USPSTF is to provide guidance to clinicians about the preventive services they offer in the primary care setting; as such, the patient visual self-examination was determined to be outside the scope of this recommendation, except insofar as to understand the effects of clinicians teaching patients to perform a skin self-examination. This intervention is more appropriately covered in the USPSTF recommendation statement on counseling to prevent skin cancer.
Most professional organizations in the United States have no specific recommendations about the clinical visual skin cancer screening examination. The American College of Physicians has no current guidance on clinician-performed skin cancer screening, nor does the American College of Preventive Medicine (the latter has an archived statement from 1998 only14). The American Academy of Family Physicians is in the process of updating its guidelines. The American Academy of Dermatology does not have a formal clinical practice guideline on skin cancer screening, although it does encourage and provide resources for its physician members to hold free skin cancer screening events for the public.15 The American Cancer Society states that adults age 20 years and older who receive periodic health examinations should have their skin examined as part of a general cancer-related checkup.16
- Howlader N, Noone AM, Krapcho M, Garshell J, Miller D, Altekruse SF, et al. SEER Cancer Statistics Review, 1975–2012. National Cancer Institute. http://seer.cancer.gov/csr/1975_2012/. Accessed November 6, 2015.
- Wernli KJ, Henrikson NB, Morrison CC, Nguyen M, Pocobelli G, Whitlock EP. Screening for Skin Cancer in Adults: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force. Evidence Synthesis No. 137. AHRQ Publication No. 14-05210-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2015.
- Katalinic A, Waldmann A, Weinstock MA, Geller AC, Eisemann N, Greinert R, et al. Does skin cancer screening save lives? An observational study comparing trends in melanoma mortality in regions with and without screening. Cancer. 2012;118(21):5395-402.
- Waldmann A, Nolte S, Geller AC, Katalinic A, Weinstock MA, Volkmer B, et al. Frequency of excisions and yields of malignant skin tumors in a population-based screening intervention of 360,288 whole-body examinations. Arch Dermatol. 2012;148(8):903-10.
- Welch HG, Woloshin S, Schwartz LM. Skin biopsy rates and incidence of melanoma: population based ecological study. BMJ. 2005;331(7515):481.
- Welch HG, Black WC. Overdiagnosis in cancer. J Natl Cancer Inst. 2010;102(9):605-13.
- Oliveria SA, Heneghan MK, Cushman LF, Ughetta EA, Halpern AC. Skin cancer screening by dermatologists, family practitioners, and internists: barriers and facilitating factors. Arch Dermatol. 2011;147(1):39-44.
- Chen SC, Bravata DM, Weil E, Olkin I. A comparison of dermatologists' and primary care physicians' accuracy in diagnosing melanoma: a systematic review. Arch Dermatol. 2001;137(12):1627-34.
- Aitken JF, Janda M, Elwood M, Youl PH, Ring IT, Lowe JB. Clinical outcomes from skin screening clinics within a community-based melanoma screening program. J Am Acad Dermatol. 2006;54(1):105-14.
- Fritschi L, Dye SA, Katris P. Validity of melanoma diagnosis in a community-based screening program. Am J Epidemiol. 2006;164(4):385-90.
- Breitbart EW, Waldmann A, Nolte S, Capellaro M, Greinert R, Volkmer B, et al. Systematic skin cancer screening in Northern Germany. J Am Acad Dermatol. 2012;66(2):201-11.
- Aitken JF, Elwood M, Baade PD, Youl P, English D. Clinical whole-body skin examination reduces the incidence of thick melanomas. Int J Cancer. 2010;126(2):450-8.
- Gambichler T, Senger E, Rapp S, Alamouti D, Altmeyer P, Hoffmann K. Deep shave excision of macular melanocytic nevi with the razor blade biopsy technique. Dermatol Surg. 2000;26(7):662-6.
- Ferrini RL, Perlman M, Hill L. American College of Preventive Medicine policy statement: screening for skin cancer. Am J Prev Med. 1998;14(1):80-2.
- SPOTme® Skin Cancer Screening Program. American Academy of Dermatology. http://www.aad.org/members/volunteer-and-mentor-opportunities/skin-cancer-screening-program. Accessed November 6, 2015.
- American Cancer Society Guidelines for the Early Detection of Cancer. American Cancer Society. http://www.cancer.org/healthy/findcancerearly/cancerscreeningguidelines/american-cancer-society-guidelines-for-the-early-detection-of-cancer. Accessed November 6, 2015.