Evidence Lacking to Recommend For, Against Skin Cancer Screening

USPSTF, AAFP Finalize Clinical Recommendation, Call for More Research

August 05, 2016 09:01 am News Staff

The U.S. Preventive Services Task Force (USPSTF) finalized its recommendation statement on skin cancer screening(www.uspreventiveservicestaskforce.org) last week, citing a lack of evidence to recommend for or against use of visual exams to screen adults for skin cancer. This "I" recommendation(www.uspreventiveservicestaskforce.org) pertains only to asymptomatic adults with no particular skin cancer risk.

[Skin cancer with sun in background]

"It is important to note that the task force's statement does not apply to people who have potential signs of skin cancer or a history of precancerous or cancerous skin lesions," said USPSTF Vice Chair David Grossman, M.D., M.P.H., in a USPSTF release,(www.uspreventiveservicestaskforce.org) "nor does it apply to those at very high risk of skin cancer, such as those with a family history of skin cancer syndromes."

Skin cancer is the most common cancer among both men and women in the United States. The most frequently diagnosed types of skin cancer are treatable and rarely prove fatal. Melanoma, however -- although less common -- carries a much higher risk of death.

In developing their recommendation statement, task force members reviewed current evidence on the effectiveness of screening for skin cancer, especially melanoma, using a full-body skin exam performed by a clinician.

According to an evidence summary(www.uspreventiveservicestaskforce.org) created for the USPSTF, an extensive literature search for relevant studies published from Jan. 1, 1995, through June 1, 2015 -- with surveillance through Feb. 16, 2016 -- failed to identify any randomized controlled trials and only limited evidence overall on the link between skin cancer screening and mortality.

One fair-quality ecologic study, for example, compared trends in melanoma mortality over a 10-year period in northern Germany, where a population-based clinical visual skin cancer screening program was initiated, with trends in the surrounding regions with no such screening program. The researchers found that age- and sex-adjusted melanoma mortality decreased by 48 percent from baseline in the intervention region during that period. Specifically, the rate dropped from 1.7 deaths (95% CI, 1.4–2.0) to 0.9 deaths (95% CI, 0.7–1.1) per 100,000 persons, yielding an overall absolute mortality difference of 0.8 melanoma deaths per 100,000 persons.

The study had important methodological limitations, the task force noted, including the potential for bias and confounding inherent in any ecologic observational study, as well as the fact that the effect of the clinical skin exam component of the intervention cannot reliably be separated from the effect of a contemporaneous public education component. Add to that the fact that melanoma mortality was already declining in the region before the screening program began, as well as other factors, and the plausibility of the observed effect is called into question.

Regarding potential harms associated with skin cancer screening, task force members concluded -- again, based on limited evidence -- that this screening carries a substantial risk of overdiagnosis and overtreatment and may be associated with psychosocial and/or cosmetic harms.

Task force member Michael Pignone, M.D., M.P.H., summed it up: "We found there is not enough evidence to know whether screening with a full-body skin exam reduces deaths from skin cancer," he said. "Rather than recommending for or against this screening, the task force is calling for more research to better understand the balance of benefits and harms."

After independently reviewing the paucity of evidence available, the AAFP has likewise given the service an "I" recommendation.

The final USPSTF recommendation statement(jama.jamanetwork.com) and its accompanying final evidence report and systematic review(jama.jamanetwork.com) were published in the July 26 issue of JAMA: The Journal of the American Medical Association. A number of related editorials appeared in the same JAMA issue, and other JAMA publications also carried editorials about the recommendation statement and its implications for clinical practice. Those resources are included below.

Related AAFP News Coverage
Evidence Lacking to Recommend Visual Skin Cancer Screening
More Study Needed to Assess Pros, Cons of Exam, Says USPSTF


More From AAFP
American Family Physician: AFP by Topic: Skin Conditions

Additional Resources
U.S. Preventive Services Task Force: Screening for Skin Cancer: Consumer Guide(www.uspreventiveservicestaskforce.org)

JAMA Editorial: Visual Inspection and the US Preventive Services Task Force Recommendation on Skin Cancer Screening(jama.jamanetwork.com)

JAMA Patient Page: Screening for Skin Cancer(jama.jamanetwork.com)

JAMA Dermatology Editorial: What the USPSTF "Insufficient" Skin Cancer Screening Recommendation Means for Primary Care Clinicians and Dermatologists(archderm.jamanetwork.com)

JAMA Internal Medicine Editorial: Skin Cancer -- The Importance of Prevention(archinte.jamanetwork.com)

JAMA Oncology Editorial: The Case for Skin Cancer Screening With Total-Body Skin Examinations(oncology.jamanetwork.com)