Accuracy in melanoma detection: a 10-year multicenter survey.

BACKGROUND: Early excision is the only strategy to reduce melanoma mortality, but unnecessary excision of benign lesions increases morbidity and healthcare costs. OBJECTIVE: To assess accuracy in melanoma detection based on number-needed-to-excise (NNE) values over a 10-year period. METHODS: Information was retrieved on all histopathologically confirmed cutaneous melanomas or melanocytic nevi that were excised between 1998 and 2007 at participating clinics. NNE values were calculated by dividing the total number of excised lesions by the number of melanomas. Analyses included changes in NNE over time, differences in NNE between specialized clinical settings (SCS) versus non-specialized clinical settings (NSCS), and patient factors influencing NNE. RESULTS: The participating clinics contributed a total of 300,215 cases, including 17,172 melanomas and 283,043 melanocytic nevi. The overall NNE values achieved in SCS and NSCS in the 10-year period were 8.7 and 29.4, respectively. The NNE improved over time in SCS (from 12.8 to 6.8), but appeared unchanged in NSCS. Most of the effect on NNE in SCS was due to a greater number of excised melanomas. Higher NNE values were observed in patients younger than 40 years and for lesions located on the trunk. LIMITATIONS: No data concerning the use of dermatoscopy and digital monitoring procedures were collected from the participating centers. CONCLUSION: Over the 10-year study period, accuracy in melanoma detection improved only in specialized clinics maybe because of a larger use of new diagnostic techniques such as dermatoscopy.