MoleMate cancer tester 'less accurate' than doctors' eyes

July 24, 2012 in Cancer

(Medical Xpress) -- Differentiating melanomas from other pigmented skin lesions in primary care is challenging - but a device used by Australian and British doctors to determine whether a patient has a melanoma has been found to be less accurate than GPs using their eyes and judgment, according to a researcher at The University of Western Australia.

In fact, MoleMate does not improve the diagnosis of melanoma but results in more patients with benign lesions being referred for investigation and treatment, according to Winthrop Professor Jon Emery, Chair of General Practice and Head of the School of Primary Aboriginal and Rural Health Care. Professor Emery, who also holds an adjunct position as Senior Clinical Research Associate at Cambridge University in the UK, works on cancer diagnosis and management in primary care, genetic medicine and the conduct of complex interventions trials.

Professor Emery is co-author of a study of the MoleMate system which looked at almost 1300 patients in 15 practices. "Worldwide, the incidence of melanoma is increasing faster than any other cancer, with an approximate doubling of rates every 10 to 20 years in countries with white populations," Professor Emery said.

"In Britain, for example, the incidence of melanoma has quadrupled over the past 40 years. Early detection is critical in reducing mortality and morbidity from melanoma, as the stage 1 disease has five-year survival rates of more than 95 per cent compared with 10-20 per cent for stage 4 of the disease. As pigmented lesions are commonly seen in primary care consultations, GPs need to be able to reassure people with benign lesions and rapidly refer those with suspicious lesions."

Published in the British Medical Journal, the study found that GPs believed the device improved their diagnostic accuracy when it actually performed no better than checklists that suggest GPs look for signs such as the size, colour and shape of lesions and any inflammation, oozing or change in sensation.

"By being perceived more positively, MoleMate provided false reassurance," Professor Emery said. "In fact, the systematic application of best practice guidelines proved more accurate."

The MoleMate system is said to be easier to learn than dermoscopy and predicts melanoma based on images of the epidermal and dermal melanin and vasculature, and the collagen content of the lesion. However, the researchers found the systematic application of best-practice guidelines, including recommended checklists, was the best way to manage suspicious-looking skin lesions in primary care.