Can dermoscopy be used accurately and effectively in primary care to improve the timely diagnosis of melanoma? A systematic review

Problem

Malignant melanoma is the 5th commonest cancer in the UK with incidence quadrupling over the last 30 years among white populations. The thickness of the melanoma at diagnosis is the most important prognostic factor with earlier diagnosis associated with thinner melanomas and better outcomes. The majority of suspicious skin lesions first present in primary care where general practitioners need to distinguish rare melanomas from common benign lesions.Dermoscopy is a non-invasive technique using a hand-held microscope and incident light to reveal subsurface images. When performed by trained specialists, dermoscopy has been shown to improve diagnosis of skin lesions. NHS specialists and CCGs are currently promoting its use by GPs; however, when used by untrained or less experienced clinicians, accuracy can be no better than inspection alone. We will focus on whether dermoscopy, with suitable formal training programmes, can be used accurately and effectively in NHS primary care.

Approach

We are performing a systematic literature review, including papers set in primary care which look at test accuracy, utility, acceptability to patients and GPs, cost-effectiveness and challenges for implementation. We have searched bibliographic databases for relevant published studies from January 1990 to December 2017 including Medline, Cochrane, EMBASE, CINAHL and SCOPUS. Any studies that are not primary studies or that are based in clinical settings other than primary care will be excluded.

Findings

487 papers were identified from the literature search and 1 through citation searching: 23 papers have been included. We are completing full data extraction by 2 researchers independently. There are large differences in the quality, design and reporting of the studies identified. Early analysis suggests that dermoscopy use in primary care, with adequate training, improves the accuracy of triaging suspicious lesions requiring urgent referral, or diagnosing melanoma. There is some evidence that use of dermoscopy is cost effective, although no significant added value of dermoscopy has been established. Training requirements appear to be the most prominent barrier to the use of dermoscopy; the high cost of dermatoscopes and the extra time needed for its use in routine clinical care are also important issues for primary care clinicians.

Consequences

Dermoscopy appears to be a useful tool to help general practitioners triage suspicious skin lesions for referral to dermatology. Improved accuracy of triaging in primary care could reduce anxiety and improve outcomes for patients, reduce the number of unnecessary referrals to secondary care, and potentially improve outcomes. However further, well-reported studies are needed to assess the accuracy of dermoscopy for use as a triage or diagnostic tool in general practice, and for the best method of training general practitioners in dermoscopy.