Moles and Site-Specific Risk of Nonfamilial Cutaneous Malignant Melanoma in Womene

Background: Cutaneous melanomas have been hypothesized to arise through different pathways according to phenotype, body site, and sun exposure. To further test this hypothesis, we explored associations between phenotype and melanoma at different sites using a case-case comparative approach.Methods: Melanoma patients (n ¼ 762) aged 18 to 79 years and diagnosed from 2007 to 2010 were ascertained from pathology laboratories in Brisbane, Australia. Patients reported phenotypic information and a dermatologist counted melanocytic nevi and solar keratoses. We compared data for patients with trunk melanoma (n ¼ 541, the reference group), head/neck melanoma (n ¼ 122), or lentigo maligna melanoma (LMM) of the head/neck (n ¼ 69). ORs and 95% confidence intervals were calculated using classical or polytomous logistic regression models.Results: Compared with trunk melanoma patients, those with head/neck melanoma were significantly less likely to have high nevus counts (135: OR ¼ 0.27; P trend ¼ 0.0004). Associations between category of nevus count and LMM head/neck were weaker and significantly different (135: OR ¼ 1.09; P trend ¼ 0.69; P homogeneity ¼ 0.02). Patients with head/neck melanoma were more likely than those with truncal melanoma to have high solar keratosis counts (7: OR ¼ 1.78, P trend ¼ 0.04). Again, associations with LMM head/neck were weaker, albeit not significantly different (7: OR ¼ 1.61; P trend ¼ 0.42; P homogeneity ¼ 0.86).Conclusion: Trunk melanomas are more strongly associated with nevus counts than head/neck melanomas, but are less strongly associated with number of solar keratoses, a marker of chronic sun exposure.Impact: These findings underscore the notion that melanomas on the trunk typically arise through a causal pathway associated with nevus propensity, whereas melanomas on the head/neck arise through a pathway associated with cumulative sun exposure. Cancer Epidemiol Biomarkers Prev; 22(12); 2222-31. Ó2013 AACR.

Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Site-Specific Determinants of Cutaneous Melanoma: A Case–Case Comparison of Patients with Tumors Arising on the Head or Trunk

Kvaskoff

Pandeya

Green

et al. 2013

“…Using the same data set, we examined these risk factors for melanoma by location of cancer. Although we have previously examined self-reported mole counts and melanoma by site in one of the cohorts, that analysis included cases from only the first 8 years of follow-up and used retrospective case-control design (4).…”

Section: Introductionmentioning

confidence: 99%

Risk Factors for Melanoma by Body Site

Cho

Rosner

Colditz

2005

193

It has been hypothesized that cutaneous melanoma at different anatomic sites develops through divergent pathways. We examined this hypothesis prospectively. We followed 152,949 women and 25,204 men free of cancer at baseline for up to 14 years in three large prospective studies. We examined risk factors for melanoma by anatomic location (head or neck, trunk, upper extremity, and lower extremity). Polytomous logistic regression was used to test the difference among risk factors by location of melanoma. A total of 511 incident cases of invasive melanoma (49 head or neck, 188 trunk, 98 upper extremity, and 176 lower extremity) were included in the analysis. Compared with females, males had a higher risk of developing melanoma on the head or neck and trunk. History of severe and painful sunburn was most strongly related to melanoma of upper extremity; individuals with >10 burns had a 6.86-fold (95% confidence interval, 2.62-18.00) higher risk of melanoma of upper extremity compared with those with no burns (P for trend < 0.0001; P for difference by body site = 0.04). Number of moles was most strongly related to melanoma of the trunk; the multivariate relative risk for having >10 moles was 4.67 (95% confidence interval, 3.07-7.11) compared with having no moles (P for trend < 0.0001; P for difference by body site = 0.04). Age, family history of melanoma, and hair color did not statistically differ by anatomic site of the cancer. These data support divergent etiologic pathways of melanoma development by anatomic sites.

“…Recent epidemiologic findings suggest there is etiologic heterogeneity among melanomas depending on whether or not there is an associated nevus (10)(11)(12)(13)(14)(15)(16)(17). A hypothesis of divergent pathways has been proposed: that high cumulative sun exposure is necessary for progression of some melanomas whereas for others ''pigment cell instability,'' manifested by a propensity to develop many nevi, is sufficient to drive progression (11,17).…”

Section: Introductionmentioning

confidence: 99%

Etiologic and Other Factors Predicting Nevus-Associated Cutaneous Malignant Melanoma

Purdue

From²,

Armstrong³

et al. 2005

Cutaneous malignant melanomas with histologic evidence of an associated nevus (N+) may have a different risk factor profile from that of melanomas without it (NÀ). To address this question, a case-only analysis of 932 people with cutaneous malignant melanoma was done to identify etiologic and other factors associated with N+ melanoma. Evidence of an associated nevus was found in 36% of melanomas. N+ melanomas were thinner (P trend = 0.0009) and more likely to be of the superficial spreading type than other types of melanoma. Subjects with N+ melanomas were younger (P trend < 0.0001) and reported a higher nevus density on their skin than subjects with NÀ melanomas [odds ratio (OR), 3.1; 95% confidence interval (CI), 1.6-6.0, for high nevus density versus no nevi]. Indicators of high accumulated sun exposure were less prevalent among subjects with N+ melanomas (OR, 0.3; 95% CI, 0.2-0.4, for melanoma location on the head and neck versus location on trunk; OR, 0.2; 95% CI, 0.1-0.4, for severe solar elastosis adjacent to the melanoma versus no elastosis; OR, 0.2; 95% CI, 0.1-0.4, for lentigo maligna melanoma subtype versus superficial spreading subtype). With the exception of solar elastosis and age, all of the aforementioned variables remained significantly associated with N+ melanomas in multivariate analyses. No associations with self-reported measures of sun exposure, sunburn, or pigmentation phenotype were apparent. Our findings provide some support for the hypothesis of etiologically separate pathways for melanoma, with N+ melanomas appearing less likely to develop in the presence of characteristics suggesting high accumulated sun exposure than NÀ melanomas. However, it is possible that high UV exposure causes involution of nevi, thus reducing the density of nevi in exposed skin and thereby the probability of N+ melanoma. (Cancer Epidemiol Biomarkers Prev 2005;14(8):2015 -22)