Anatomic distribution of acquired melanocytic nevi in white children. A comparison with melanoma: the Vancouver Mole Study
R. P. Gallagher, D. I. McLean, C. P. Yang, A. J. Coldman, H. K. Silver, J. J. Spinelli and M. Beagrie
Division of Epidemiology, Biometry, and Occupational Oncology, Cancer Control Agency of British Columbia, Vancouver, Canada.
The presence of acquired benign nevi is a risk factor for cutaneous
melanoma, yet relatively little is known about the etiology of nevi. We
have conducted a study of the prevalence of melanocytic nevi among 1146
white Vancouver (Canada) schoolchildren aged 6 to 18 years. Numbers of nevi
per square meter of body surface area increase with age in children of both
sexes. Male adolescents have more nevi than female adolescents on the head
and neck as well as on the trunk, while prevalence in females is higher on
the upper and lower limbs. This distribution parallels that of cutaneous
melanoma in British Columbia adults. Nevi are more common in children on
intermittently exposed body sites than on constantly or minimally
sun-exposed sites. This suggests that exposure to strong intermittent
sunlight in childhood (a risk factor for cutaneous melanoma) may also be
important in the etiology of acquired benign nevi.
