FACTORES CLÍNICOS, EPIDEMIOLÓGICOS, ANATOMOPATOLÓGICOS Y GENÉTICOS ASOCIADOS AL MELANOMA SOBRE NEVO.

Abstract

Background:_x000D_ Two divergent pathways have been described for cutaneous melanoma development. The pigment cell instability pathway is associated with melanoma on intermittent sun-exposed areas, young patients and high number of moles. Recently, cutaneous melanoma has been linked to genetic variants of pigmentation and nevus genes. The vast majority of melanomas appear from de novo, however a small percentage of them appear in histological association to a benign melanocytic nevus (Melanoma arising in nevus, MSN). It is unknown the meaning of genetic variants in pigmentation and nevus genes in MSN, and which situation MSN plays in the pigment cell instability pathway. Moreover, patients diagnosed of cutaneous melanoma have more risk than general population for developing a second cutaneous melanoma. Risks factors associated to the second MSN remains unknown._x000D_ Objectives: Find out the prevalence of MSN and the accumulated incidence of second melanomas, specifically MSN, and analyze risk factors associated to the first and second MSN._x000D_ Methods: Descriptive and analytical epidemiological study of 2714 patients diagnosed of at least one cutaneous melanoma. _x000D_ Results: 20.2% of the patients developed MSN. It was statistically associated to: age ≤50 (OR: 1.28, CI 95%:1.03-1.6), trunk location (OR: 1.66, IC 95%: 1.32-2.08), superficial spreading (OR: 6.95, IC 95%:3.40-12.09) and nodular melanoma (OR: 4.18, IC 95%:2.22-7.81), the presence of at least one atypical nevus (OR:1,81, IC al 95%:1,24-2,65) and RHC variants of MC1R gene (OR:1.56, IC al 95%: 1,1-2,22). 2.3% of patients developed a second cutaneous melanoma during follow-up. 26.4% of those melanomas were MSN. The male gender was the only risk factor in this population (OR: 5.54, IC 95%:1.18-26.03)._x000D_ Limitations: The reduced cases of patients with more than one cutaneous melanoma._x000D_ Conclusions: young ages, trunk location, superficial spreading melanoma and nodular melanoma, presence of at least one atypical melanocytic nevus and RHC variants of MC1R gene are associated to the first melanoma arising in nevus. The male gender is associated to the second melanoma arising in nevus.

Date of Award	19 Dec 2014
Original language	Spanish
Supervisor	Carlos Ferrándiz Foraster (Director) & Eduardo Nagure Enguianos (Director)