Funding sources Funding for Twins, U.K.: The study was funded by the Welcome Trust; European Community's Seventh Framework Programme (FP7/2007-2013). The study also receives support from the National Institute for Health Research (NIHR)-funded BioResource, Clinical Research Facility and Biomedical Research Centre based at Guy's and St. Thomas' NHS Foundation Trust in partnership with King's College London. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
Prediction of high naevus count in a healthy U.K. population to estimate melanoma risk
Version of Record online: 14 DEC 2015
© 2015 British Association of Dermatologists
British Journal of Dermatology
Volume 174, Issue 2, pages 312–318, February 2016
How to Cite
Ribero, S., Zugna, D., Osella-Abate, S., Glass, D., Nathan, P., Spector, T. and Bataille, V. (2016), Prediction of high naevus count in a healthy U.K. population to estimate melanoma risk. British Journal of Dermatology, 174: 312–318. doi: 10.1111/bjd.14216
Conflicts of interest None declared.
S.R. and D.Z. both contributed equally.
- Issue online: 12 FEB 2016
- Version of Record online: 14 DEC 2015
- Accepted manuscript online: 19 OCT 2015 07:45AM EST
- Manuscript Accepted: 28 SEP 2015
- Welcome Trust
- European Community's Seventh Framework Programme. Grant Number: FP7/2007-2013
- National Institute for Health Research (NIHR)-funded BioResource
- Clinical Research Facility and Biomedical Research Centre
- St. Thomas' NHS Foundation Trust based at Guy's
Despite recent discoveries of germline and somatic mutations in melanoma, naevus count remains the most important risk factor for melanoma. Counting naevi on the whole body is time consuming. In order to identify patients at risk for melanoma, many studies have used naevus count on selected body sites as a proxy for total body naevus count (TBNC).
The main aim of this study was to assess the predictive value of naevus count on 17 different body sites in estimating TBNC in a large cohort of healthy U.K. Caucasian female subjects. Once the site with the best predictive value for TBNC was determined, a second aim was to estimate the cut-off values of naevus counts at this anatomical site that best predict the presence of 50 or 100 naevi, respectively.
The most predictive body site for TBNC was assessed in a cohort of healthy female twins. This finding was replicated on a control group from a U.K. case–control study and a prediction model was performed afterwards. The area under the receiver operating characteristics curve was used to evaluate the best cut-off for the prediction of having a TBNC of more than 50 or 100.
There were 3694 female twins included. The TBNC showed a steady decline after the age of 30 years (P < 0·001). The most predictive sites for TBNC were the arms and legs: the adjusted correlation coefficients were 0·50 and 0·51 (P < 0·001) for the right and left arm, respectively, and 0·49 and 0·48 for the right and left legs, respectively (P < 0·001). The arm remained the most predictive site for TBNC when replicated in a control population including both sexes. In the twin study, women with more than 11 naevi on the right arm were approximately nine times more likely to have more than 100 naevi (odds ratio = 9·38, 95% confidence interval 6·71–13·11).
The ability to estimate TBNC quickly by counting naevi on one arm could be a very useful tool in assessing melanoma risk in primary care.