Am Fam Physician. 2004;69(4):903-904
This statement summarizes the current U.S. Preventive Services Task Force (USPSTF) recommendation on counseling to prevent skin cancer and the supporting scientific evidence, and updates the 1996 recommendation contained in the Guide to Clinical Preventive Services, second edition.1 Explanations of the ratings and of the strength of overall evidence are given in Tables 1 and 2, respectively. The full USPSTF recommendations and rationale statement on this topic, which includes a brief review of the supporting evidence, is available through the USPSTF Web site (http://www.ahrq.gov/clinic/uspstfix.htm) and the National Guideline Clearinghouse (http://www.guideline.gov). The complete information on which this statement is based, including evidence tables and references, is available in the summary of the evidence2 at the USPSTF Web site. The summary of the evidence and the recommendations statement also are available in print by subscription through the AHRQ Publications Clearinghouse (telephone, 800-358-9295; e-mail, ahrqpubs@ahrq.gov).
Summary of Recommendations
The USPSTF concludes that the evidence is insufficient to recommend for or against routine counseling by primary care clinicians to prevent skin cancer. I recommendation.
| The USPSTF grades its recommendations according to one of five classifications (A, B, C, D, or I) reflecting the strength of evidence and magnitude of net benefit (benefits minus harms). | |
| A. | The USPSTF strongly recommends that clinicians provide [the service] to eligible patients. The USPSTF found good evidence that [the service] improves important health outcomes and concludes that benefits substantially outweigh harms. |
| B. | The USPSTF recommends that clinicians provide [the service] to eligible patients. The USPSTF found at least fair evidence that [the service] improves important health outcomes and concludes that benefits outweigh harms. |
| C. | The USPSTF makes no recommendation for or against routine provision of [the service]. The USPSTF found at least fair evidence that [the service] can improve health outcomes but concludes that the balance of benefits and harms is too close to justify a general recommendation. |
| D. | The USPSTF recommends against routinely providing [the service] to asymptomatic patients. The USPSTF found at least fair evidence that [the service] is ineffective or that harms outweigh benefits. |
| I. | The USPSTF concludes that the evidence is insufficient to recommend for or against routinely providing [the service]. Evidence that [the service] is effective is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined. |
The USPSTF found insufficient evidence to determine whether clinician counseling is effective in changing patient behaviors to reduce skin cancer risk. Counseling parents may increase the use of sunscreen for children, but there is little evidence to determine the effects of counseling on other preventive behaviors (e.g., wearing protective clothing, reducing excessive sun exposure, avoiding sun lamps and tanning beds, practicing skin self-examination) and little evidence on potential harms.
Clinical Considerations
Using sunscreen has been shown to prevent squamous cell skin cancer. The evidence for the effect of sunscreen use in preventing melanoma, however, is mixed. Sunscreens that block both ultraviolet A (UV-A) and ultraviolet B (UV-B) light may be more effective in preventing squamous cell cancer and its precursors than those that block only UV-B light. However, people who use sunscreen alone could increase their risk for melanoma if they increase the time they spend in the sun.
UV exposure increases the risk for skin cancer among people with all skin types, but especially fair-skinned people. Those who sunburn readily and tan poorly, namely those with red or blond hair and fair skin that freckles or burns easily, are at highest risk for developing skin cancer and would benefit most from sun protection behaviors. The incidence of melanoma among whites is 20 times higher than it is among blacks; the incidence of melanoma among whites is about four times higher than it is among Hispanics.
Observational studies indicate that intermittent or intense sun exposure is a greater risk factor for melanoma than chronic exposure. These studies support the hypothesis that preventing sunburn, especially in childhood, may reduce the lifetime risk for melanoma.
Other measures for preventing skin cancer include avoiding direct exposure to midday sun (between the hours of 10 a.m. and 4 p.m.) to reduce exposure to ultraviolet rays and covering skin exposed to the sun (by wearing protective clothing such as broad-brimmed hats, long-sleeved shirts, long pants, and sunglasses).
The effects of sunlamps and tanning beds on the risk for melanoma are unclear due to limited study design and conflicting results from retrospective studies.
Only a single case-control study of skin self-examination has reported a lower risk for melanoma among patients who reported ever examining their skin over five years. Although results from this study suggest that skin self-examination may be effective in preventing skin cancer, these results are not definitive.
| The USPSTF grades the quality of the overall evidence for a service on a three-point scale (good, fair, or poor). | |
| Good: | Evidence includes consistent results from well-designed, well-conducted studies in representative populations that directly assess effects on health outcomes. |
| Fair: | Evidence is sufficient to determine effects on health outcomes, but the strength of the evidence is limited by the number, quality, or consistency of the individual studies; generalizability to routine practice; or indirect nature of the evidence on health outcomes. |
| Poor: | Evidence is insufficient to assess the effects on health outcomes because of limited number or power of studies, important flaws in their design or conduct, gaps in the chain of evidence, or lack of information on important health outcomes. |
The Scientific Evidence and Recommendations of Others sections that usually are included in USPSTF recommendation statements are available in the full recommendations and rationale statement on the USPSTF Web site (http://www.ahrq.gov/clinic/uspstfix.htm).