Sun exposure, phenotypic characteristics, and cutaneous malignant melanoma. An analysis according to different clinico-pathological variants and anatomic locations (Italy).

OBJECTIVE

The aim of the study was to examine the relation between sun exposure and other selected risk factors and the development of different clinico-pathological variants of cutaneous malignant melanoma (CMM) at different body locations.

METHODS

We analysed data from a case-control study conducted in Italy between 1992 and 1994 on 542 cases of CMM and 538 hospital controls. Clinico-pathological variants included 391 superficial spreading (SSM), 72 nodular (NM) and 39 lentigo maligna (LMM) melanomas.

RESULTS

The risk of SSM increased for a high education level (odds ratio, OR = 1.5, 95% confidence interval, CI, 1.0-2.2), sunburn episodes before age 15 (OR = 1.8, 95% CI, 1.1-2.8), light eye colour (OR = 1.6, 95% CI, 1.1-2.4) and solar lentigines (OR = 1.4, 95% CI, 1.0-1.8). The ORs for total number of nevi >30 were 4.4 (95% CI, 2.9-6.7) for SSM, 5.7 (95% CI, 2.6-12.5) for NM and 2.2 (95% CI, 0.5-9.4) for LMM. The risk of CMM located on the trunk seemed to be higher for a high education level (OR = 1.6, 95% CI, 1.0-2.6) and propensity to sunburn (OR = 1.6, 95% CI, 0.8-3.2). The ORs for sunburn episodes, eye and skin colour, and solar lentigines tended to be higher for CMM located on the face/neck and on the upper limbs than the trunk. Total number of nevi was strongly associated with all anatomic locations.

CONCLUSIONS

Total number of nevi was the major risk factor associated with all melanoma variants and locations. A higher level of education and sunburn episodes in early childhood appeared to be more strongly related to SSM than to other variants.