Development of an individual score for melanoma risk.

Melanoma is one of the fastest growing cancers worldwide. We need to have tools to identify patients with high risk of melanoma. We carried out a case-control study and tested three methods to develop an individual score of melanoma risk, usable in routine practice. All cases included newly diagnosed invasive cutaneous melanoma of stage I or II (6th American Joint Committee on Cancer) seen in 2007 at the Skin Cancer Unit of Nantes Hospital, France. Controls included 1500 consecutive patients consulting their general practitioners. A self-administrated questionnaire was used for assessment of melanoma risk factors. Three methods of scoring were used and compared: one with common relative risks reported in the literature, one with odds ratios estimated by logistic regression, and a combinatorial analysis. The method based on combinatorial analysis permitted one to obtain a simple rule to define individuals at risk: the association of the rule 'presence of at least three risk factors or presence of more than 20 naevi on the arms' for the patients aged under 60 years and 'presence of at least three risk factors or presence of freckles' for the patients aged 60 years and above (sensitivity: 63.2% and specificity: 68.8%). The tool we propose is easy to use every day in routine health care to select patients with high risk of melanoma. It can be assessed without any computer or calculator and is based on the self-assessment of the melanoma risk factors by the patient and thus is not medical time consuming.