BACKGROUND: Histopathologic association between melanocytic nevus and melanoma has been reported in approximately 10% to more than 50% of melanoma cases. Whether melanomas in contiguity with a nevus have a different natural history and pathogenesis from melanomas without a nevus is still to be determined. OBJECTIVE: The present study was undertaken to clarify whether melanocytic nevus-associated melanomas (MN[+]) have a different risk factor profile from cases without histopathologic evidence of melanocytic nevus association (MN[-]). METHODS: The study population consisted of 131 invasive melanoma cases with a thickness of 4.00 mm or less and 174 control cases without melanomas. The whole series was evaluated for the following risk factors: phenotypic traits; the number of common, atypical, and congenital nevus-like nevi; and freckling and history of sunburns. Melanoma cases were revised for the presence of associated melanocytic nevi. The analysis of risk factors was performed by a case-control approach comparing cases, classified by histologic association with nevus, to the group of controls. Possible differences in risk factor distribution between MN(+) cases and MN(-) cases were evaluated with a polychotomous logistic regression model and a likelihood ratio test for heterogeneity. RESULTS: Histopathologic association between melanocytic nevus and melanoma was found in 27 cases (20.6%). Phenotypic traits were shown to be more powerful predictors of risk for MN(-) than for MN(+) cases (blond/red hair; odds ratio, 7.4 and 1.2, respectively; likelihood ratio test for heterogeneity, 4.13; P < .05). Conversely, history of frequent sunburn was a risk factor only in MN(+) cases (more than 5 sunburns; odds ratio, 6.7; 95% confidence interval, 1.3-33.7), but not in MN(-) cases (odds ratio, 1.2; 95% confidence interval, 0.3-4.0; likelihood ratio test for heterogeneity, 4.2; P < .05). Where melanocytic nevi are concerned, an increased number of common nevi was a predictor of melanoma risk in both MN(+) and MN(-) cases, but with a different magnitude of risk, higher for MN(+) cases (number of common nevi, 10-30; odds ratio, 14.4 and 4.7, respectively; likelihood ratio test for heterogeneity, 3.7; P = .055). CONCLUSION: This study showed that, although MN(+) and MN(-) melanomas share many risk factors, there is a different strength of association between the 2 groups. The effect of a history of sunburn as a predictor of risk was found only for nevus-associated melanomas, suggesting a possible role of sunburns in the neoplastic transformation of nevi.
BACKGROUND: Histopathologic association between melanocytic nevus and melanoma has been reported in approximately 10% to more than 50% of melanoma cases. Whether melanomas in contiguity with a nevus have a different natural history and pathogenesis from melanomas without a nevus is still to be determined. OBJECTIVE: The present study was undertaken to clarify whether melanocytic nevus-associated melanomas (MN[+]) have a different risk factor profile from cases without histopathologic evidence of melanocytic nevus association (MN[-]). METHODS: The study population consisted of 131 invasive melanoma cases with a thickness of 4.00 mm or less and 174 control cases without melanomas. The whole series was evaluated for the following risk factors: phenotypic traits; the number of common, atypical, and congenital nevus-like nevi; and freckling and history of sunburns. Melanoma cases were revised for the presence of associated melanocytic nevi. The analysis of risk factors was performed by a case-control approach comparing cases, classified by histologic association with nevus, to the group of controls. Possible differences in risk factor distribution between MN(+) cases and MN(-) cases were evaluated with a polychotomous logistic regression model and a likelihood ratio test for heterogeneity. RESULTS: Histopathologic association between melanocytic nevus and melanoma was found in 27 cases (20.6%). Phenotypic traits were shown to be more powerful predictors of risk for MN(-) than for MN(+) cases (blond/red hair; odds ratio, 7.4 and 1.2, respectively; likelihood ratio test for heterogeneity, 4.13; P < .05). Conversely, history of frequent sunburn was a risk factor only in MN(+) cases (more than 5 sunburns; odds ratio, 6.7; 95% confidence interval, 1.3-33.7), but not in MN(-) cases (odds ratio, 1.2; 95% confidence interval, 0.3-4.0; likelihood ratio test for heterogeneity, 4.2; P < .05). Where melanocytic nevi are concerned, an increased number of common nevi was a predictor of melanoma risk in both MN(+) and MN(-) cases, but with a different magnitude of risk, higher for MN(+) cases (number of common nevi, 10-30; odds ratio, 14.4 and 4.7, respectively; likelihood ratio test for heterogeneity, 3.7; P = .055). CONCLUSION: This study showed that, although MN(+) and MN(-) melanomas share many risk factors, there is a different strength of association between the 2 groups. The effect of a history of sunburn as a predictor of risk was found only for nevus-associated melanomas, suggesting a possible role of sunburns in the neoplastic transformation of nevi.
Authors: Yu-mei Chang; Julia A Newton-Bishop; D Timothy Bishop; Bruce K Armstrong; Veronique Bataille; Wilma Bergman; Marianne Berwick; Paige M Bracci; J Mark Elwood; Marc S Ernstoff; Adèle C Green; Nelleke A Gruis; Elizabeth A Holly; Christian Ingvar; Peter A Kanetsky; Margaret R Karagas; Loïc Le Marchand; Rona M Mackie; Håkan Olsson; Anne Østerlind; Timothy R Rebbeck; Kristian Reich; Peter Sasieni; Victor Siskind; Anthony J Swerdlow; Linda Titus-Ernstoff; Michael S Zens; Andreas Ziegler; Jennifer H Barrett Journal: Int J Cancer Date: 2009-01-15 Impact factor: 7.396
Authors: Catherine M Olsen; Michael S Zens; Therese A Stukel; Carlotta Sacerdote; Yu-Mei Chang; Bruce K Armstrong; Veronique Bataille; Marianne Berwick; J Mark Elwood; Elizabeth A Holly; Connie Kirkpatrick; Thomas Mack; Julia Newton Bishop; Anne Østerlind; Anthony J Swerdlow; Roberto Zanetti; Adèle C Green; Margaret R Karagas; David C Whiteman Journal: Int J Cancer Date: 2009-02-15 Impact factor: 7.396
Authors: Leslie K Dennis; Marta J Vanbeek; Laura E Beane Freeman; Brian J Smith; Deborah V Dawson; Julie A Coughlin Journal: Ann Epidemiol Date: 2008-08 Impact factor: 3.797