Regional distribution of common and dysplastic naevi in relation to melanoma site and sun exposure. A case-control study.

• The frequency of melanoma (CMM), and of common and dysplastic naevi (CN and DN) in areas of skin chronically, intermittently and rarely exposed to UV light was investigated in 121 melanoma patients (30-50 years) and 310 controls. Both cases and controls had significantly more CN in intermittently exposed areas than in areas chronically or rarely exposed. The ratio of observed to expected number of CMM was also highest in intermittently exposed skin (1.3 compared to 0.8 in chronically exposed and 0.5 in rarely exposed areas). Thus, intermittent UV exposure seems to have the most potent 'naevogenic' as well as carcinogenic effect on melanocytes. Nineteen per cent of controls and 56% of cases had naevi fulfilling the clinical criteria for DN. The distribution pattern of DN was clearly different from that of CN and does not accord with the idea that UV light is a major aetiological factor for DN. The probability of CMM significantly increased with the degree of relative clustering of CN (p less than 0.05) and of DN (p less than 0.01). This co-variation of naevi and CMM over the body surface might be the result of the local insults to the melanocyte system caused by UV light and/or to the fact that naevi are precursor lesions of CMM.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Keyword

Adult

Case-Control Studies

Disease Susceptibility

Dysplastic Nevus Syndrome

epidemiology

etiology

Humans

Male

Melanocytes

pathology

radiation effects

Melanoma

epidemiology

etiology

Middle Aged

Neoplasms

Multiple Primary

epidemiology

Neoplasms

Radiation-Induced

epidemiology

Nevus

Pigmented

epidemiology

Precancerous Conditions

epidemiology

Sex Factors

Skin Neoplasms

epidemiology

etiology

Sunlight

adverse effects

Sweden

epidemiology

Ultraviolet Rays

adverse effects

Publication and Content Type

ref (subject category)

art (subject category)