Inspecting suspicious skin lesions using the naked eye may not be sufficient to produce accurate skin cancer diagnoses, according to a large scale systematic review on the accuracy of skin cancer diagnosis tests, published online ahead of print in The Cochrane Database of Systematic Reviews (Dec. 3, 2018).
“We have found that careful consideration should be given of the technologies that could be used to make sure that skin cancers are not missed, at the same time ensuring that inappropriate referrals for specialist assessment and inappropriate excision of benign skin lesions are kept to a minimum,” said lead study author Jac Dinnes, PhD, senior researcher in the Unit of Public Health, Epidemiology and Biostatistics at the University of Birmingham’s Institute of Applied Health Research in Birmingham, U.K., in a press release.
Further analyses are also needed to determine whether the accuracy of visual inspection can
be improved by checklists. Photo by Skincareaus from Wikimedia.comvia CC BY-SA 4.0.
Dr. Dinnes and her colleagues found that smartphone applications used by patients who are concerned about changing moles or other skin lesions also have a high chance of missing melanomas.
Furthermore, high frequency ultrasound shows promise, particularly for the diagnosis of BCCs, but the evidence base is small and more research is needed to confirm efficacy.
Investigators concluded that further research is needed on the use of specialist tests such as reflectance confocal microscopy (RCM) that allow physicians to conduct ‘virtual biopsies’ of the skin.
Findings related to the efficacy of dermoscopy were particularly significant, according to the researchers. When used by specialists, dermoscopy is better at diagnosing melanoma than visual inspection alone, and may help in the diagnosis of BCCs. The diagnostic tool may also help general practitioners to correctly identify patients with suspicious lesions and refer them to dermatology specialists.
“Apart from a few exceptions, I was surprised by how poor the overall study designs were, especially in terms of accurately documenting where on the clinical pathway patients were tested . . . the greatest value of the research is to serve as a yardstick for designing future studies evaluating skin cancer diagnosis techniques on patients who are typically seen in GP and specialist settings,” said Dr. Hywel Williams, Cochrane Skin Group founder, professor in the Department of Dermato-Epidemiology, and co-director of the Centre of Evidence Based Dermatology, Faculty of Medicine & Health Sciences at the University of Nottingham in Nottingham, U.K.
Checklists to help interpret dermoscopy might improve the accuracy of diagnosis for practitioners with less expertise. Artificial intelligence techniques, such as computer-assisted diagnosis (CAD), can identify more melanomas than doctors utilizing dermoscopy images.
However, CAD systems also produce far more false positive diagnoses than dermoscopy and could lead to considerable increases in unnecessary surgery.
Teledermatology continues to be an effective tool for helping general practitioners to decide which skin lesions need to be seen by a skin specialist, but future studies are needed to validate these conclusions.
“Early and accurate detection of all skin cancer types is essential to manage the disease and to improve survival rates in melanoma, especially given the rate of skin cancer worldwide is rising,” said Dr. Dinnes.