The U.S. Preventive Services Task Force has released a final recommendation statement on screening for skin cancer. The Task Force found insufficient evidence to recommend for or against using visual examinations by clinicians to screen adults for skin cancer. The statement was published online in the Journal of the American Medical Association.
The Task Force’s 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 the recommendation statement.
Direct evidence to assess the effect of screening with a clinical visual skin examination on the risk of death from skin cancer is limited, according to the statement. A single ecological study (Skin Cancer Research to Provide Evidence for Effectiveness of Screening in Northern Germany [SCREEN]) with important methodological limitations suggests that a one-time, general population-based screening program (with limited participation of 19%) combined with a disease awareness campaign may result in, at most, one fewer death due to melanoma per 100,000 persons over a decade. An independent analysis of the SCREEN population found that the observed melanoma mortality rate returned to pre-intervention levels after five years of follow-up.
Information on the harms of screening is also sparse. Most suspicious skin lesions excised during screening are not cancerous, according to the Task Force. For example, the SCREEN study found that between 20 and 55 excisions were performed to detect one case of melanoma, depending on the patient’s age. The SCREEN study did not report the number of excisions required to prevent one death from melanoma, but it can be estimated at more than 4,000. Overdiagnosis and overtreatment—the diagnosis and treatment of cancer that would never have harmed the patient in the absence of screening—are other important potential harms, according to the statement. Ecological evidence suggests that screening with a visual skin examination results in the overdiagnosis of skin cancer; however, current evidence is insufficient to be reliably certain of the magnitude of this effect, the Task Force says.
Contemporary data on clinician practice patterns related to skin cancer screening are also limited. In a 2005 survey of U.S. physicians, 81% of dermatologists, 60% of primary care physicians, and 56% of internists reported performing a full-body visual skin cancer screening examination on their adult patients. The clinical visual skin 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 Task Force has concluded that the current evidence is insufficient to assess the balance of benefits and harms of screening for skin cancer with a clinical visual skin examination in adults.