Guidance of sentinel lymph node biopsy decisions in patients with T1-T2 melanoma using gene expression profiling.

AIM: Can gene expression profiling be used to identify patients with T1-T2 melanoma at low risk for sentinel lymph node (SLN) positivity? PATIENTS & METHODS: Bioinformatics modeling determined a population in which a 31-gene expression profile test predicted \u3c5% SLN positivity. Multicenter, prospectively-tested (n = 1421) and retrospective (n = 690) cohorts were used for validation and outcomes, respectively. RESULTS: Patients 55-64 years and ≥65 years with a class 1A (low-risk) profile had SLN positivity rates of 4.9% and 1.6%. Class 2B (high-risk) patients had SLN positivity rates of 30.8% and 11.9%. Melanoma-specific survival was 99.3% for patients ≥55 years with class 1A, T1-T2 tumors and 55.0% for class 2B, SLN-positive, T1-T2 tumors. CONCLUSION: The 31-gene expression profile test identifies patients who could potentially avoid SLN biopsy

In Vitro Behavior and UV response of melanocytes derived from carriers of CDKN2A mutations and MC1R variants.

Co-inheritance of germline mutation in cyclin-dependent kinase inhibitor 2A (CDKN2A) and loss-of-function (LOF) melanocortin 1 receptor (MC1R) variants is clinically associated with exaggerated risk for melanoma. To understand the combined impact of these mutations, we established and tested primary human melanocyte cultures from different CDKN2A mutation carriers, expressing either wild-type MC1R or MC1R LOF variant(s). These cultures expressed the CDKN2A product p16 (INK4A) and functional MC1R. Except for 32ins24 mutant melanocytes, the remaining cultures showed no detectable aberrations in proliferation or capacity for replicative senescence. Additionally, the latter cultures responded normally to ultraviolet radiation (UV) by cell cycle arrest, JNK, p38, and p53 activation, hydrogen peroxide generation, and repair of DNA photoproducts. We propose that malignant transformation of melanocytes expressing CDKN2A mutation and MC1R LOF allele(s) requires acquisition of somatic mutations facilitated by MC1R genotype or aberrant microenvironment due to CDKN2A mutation in keratinocytes and fibroblasts. This article is protected by copyright. All rights reserved

Population-Based Prevalence of CDKN2A Mutations in Utah Melanoma Families

Cyclin-dependent kinase inhibitor 2A (CDKN2A or p16) is the major melanoma predisposition gene. In order to evaluate the candidacy for genetic testing of CDKN2A mutations among melanoma prone families, it is important to identify characteristics that predict a high likelihood of carrying a CDKN2A mutation. We primarily used a unique Utah genealogical resource to identify independent melanoma prone families whom we tested for mutations in CDKN2A, cyclin-dependent kinase 4, and alternate reading frame. We sampled 60 families which met the inclusion criteria of two or more affected first-degree relatives. We found four different pathogenic CDKN2A mutations in five families, mutations of uncertain significance in two families, and known polymorphisms in three families. One of the mutations of uncertain significance, 5′ untranslated region −25C>T, has not been previously described. Among our population-based set of Utah families, the prevalence of CDKN2A mutations was 8.2% (4/49); the overall prevalence when physician-referred pedigrees were also considered was between 8.3% (5/60) and 10% (6/60). Having four or more first- or second-degree relatives with melanoma, or a family member with ≥3 primary melanomas, correlated strongly with carrying a CDKN2A mutation. We observed a significantly elevated rate of pancreatic cancer in one of four families with a deleterious CDKN2A mutation

Melanoma Literacy among the General Population of three Western US states

Melanoma is a significant cause of cancer death, despite being detectable without specialized or invasive technologies. Understanding barriers to preventive behaviors such as skin self-examination (SSE) could help to define interventions for increasing the frequency of early detection. To determine melanoma knowledge and beliefs across three high-incidence US states, 15,000 surveys were sent to a population-representative sample. We aimed to assess (1) melanoma literacy (i.e., knowledge about melanoma risks, attitudes, and preventive behaviors) and (2) self-reported SSE and its association with melanoma literacy, self-efficacy, and belief in the benefits of SSE. Of 2326 respondents, only 21.2% provided responses indicating high knowledge of melanoma, and 62.8% reported performing an SSE at any time in their lives. Only 38.3% and 7.3% reported being “fairly” or “very” confident about doing SSE, respectively. SSE performance among respondents was most strongly associated with higher melanoma knowledge, higher self-efficacy, and personal history of melanoma. Melanoma literacy among survey respondents was modest, with greater literacy associated with a higher likelihood of reported preventive behavior. This assessment establishes a baseline and provides guidance for public health campaigns designed to increase prevention and early detection of this lethal cancer

Epistatic and Combinatorial Effects of Pigmentary Gene Mutations in the Domestic Pigeon

SummaryUnderstanding the molecular basis of phenotypic diversity is a critical challenge in biology, yet we know little about the mechanistic effects of different mutations and epistatic relationships among loci that contribute to complex traits. Pigmentation genetics offers a powerful model for identifying mutations underlying diversity and for determining how additional complexity emerges from interactions among loci. Centuries of artificial selection in domestic rock pigeons (Columba livia) have cultivated tremendous variation in plumage pigmentation through the combined effects of dozens of loci. The dominance and epistatic hierarchies of key loci governing this diversity are known through classical genetic studies [1–6], but their molecular identities and the mechanisms of their genetic interactions remain unknown. Here we identify protein-coding and cis-regulatory mutations in Tyrp1, Sox10, and Slc45a2 that underlie classical color phenotypes of pigeons and present a mechanistic explanation of their dominance and epistatic relationships. We also find unanticipated allelic heterogeneity at Tyrp1 and Sox10, indicating that color variants evolved repeatedly though mutations in the same genes. These results demonstrate how a spectrum of coding and regulatory mutations in a small number of genes can interact to generate substantial phenotypic diversity in a classic Darwinian model of evolution [7]

Skin examination behavior: the role of melanoma history, skin type, psychosocial factors, and region of residence in determining clinical and self-conducted skin examination

Objective: To examine the frequency and correlates of skin examination behaviors in an international sample of individuals at varying risk of developing melanoma. Design: A cross-sectional, web-based survey. Setting: Data were collected from the general population over a 20-month period on behalf of the Melanoma Genetics Consortium (GenoMEL). Participants: A total of 8178 adults from Northern (32%), Central (33%), and Southern (14%) Europe, Australia (13%), and the United States (8%). Main outcome measures: Self-reported frequency of skin self-examination (SSE) and clinical skin examination (CSE). Results: After adjustment for age and sex, frequency of skin examination was higher in both Australia (odds ratio [OR]SSE=1.80 [99% CI, 1.49-2.18]; ORCSE=2.68 [99% CI, 2.23-3.23]) and the United States (ORSSE=2.28 [99% CI, 1.76-2.94]; ORCSE=3.39 [99% CI, 2.60-4.18]) than in the 3 European regions combined. Within Europe, participants from Southern Europe reported higher rates of SSE than those in Northern Europe (ORSSE=1.61 [99% CI, 1.31-1.97]), and frequency of CSE was higher in both Central (ORCSE=1.47 [99% CI, 1.22-1.78]) and Southern Europe (ORCSE=3.46 [99% CI, 2.78, 4.31]) than in Northern Europe. Skin examination behavior also varied according to melanoma history: participants with no history of melanoma reported the lowest levels of skin examination, while participants with a previous melanoma diagnosis reported the highest levels. After adjustment for region, and taking into account the role of age, sex, skin type, and mole count, engagement in SSE and CSE was associated with a range of psychosocial factors, including perceived risk of developing melanoma; perceived benefits of, and barriers to, skin examination; perceived confidence in one's ability to engage in screening; and social norms. In addition, among those with no history of melanoma, higher cancer-related worry was associated with greater frequency of SSE. Conclusions: Given the strong association between psychosocial factors and skin examination behaviors, particularly among people with no history of melanoma, we recommend that greater attempts be made to integrate psycho-education into the fabric of public health initiatives and clinical care, with clinicians, researchers, and advocacy groups playing a key role in guiding individuals to appropriate tools and resources