Genetics of melanoma predisposition

Cutaneous Melanoma and Glioblastoma Multiforme Association—Case Presentation and Literature Review

The occurrence of both melanoma and glioma was first suggested by the observation of a familial association between these conditions, which was later confirmed by the description of the melanoma–astrocytoma syndrome, an extremely rare, inherited affliction in which people have an increased risk of developing melanoma and nervous system tumors. Taking into consideration the common embryologic precursor, the neuroectoderm, it was hypothesized that this syndrome is associated with a genetic disorder. While some families with germline CDKN2A mutations are prone to develop just melanomas, others develop both melanomas and astrocytomas or even other nervous-system neoplasms. Herein, we report the case of a 63-year-old male patient with no personal or family history of malignancy who had primary melanoma followed by glioblastoma. Our case report suggests that the occurrence of both melanoma and glioblastoma is most likely not coincidental but instead linked to genetic mutations of common embryologic precursors or signaling pathways.

A Japanese case of familial malignant melanoma with germline CDK4 variant incidentally diagnosed by cancer genome profiling

Familial malignant melanoma (FMM) is a hereditary tumor that is quite rare in Japan; to date, the germline CDK4 variant has scarcely been reported around the world. Thus, we report on a woman with FMM who developed salivary gland cancer, for which a germline pathogenic variant of CDK4 was incidentally identified through comprehensive genomic profiling. She had a history of multiple atypical nevi and a facial melanoma since her 30 s and multiple family histories of melanoma; however, none of her relatives were aware of its heredity. Genetic counseling and skin surveillance were performed. Precision medicine for cancer can discover this rare genetic syndrome and provides us with the opportunity to manage the health of patients and their relatives.

Melanoma and Glioblastoma-Not a Serendipitous Association

Recently, we came across a patient with malignant melanoma and primary glioblastoma. Given this, we parsed the literature to ascertain the relationship, if any, between these 2 malignancies. We begin with a brief overview of melanoma and glioma in isolation followed by a chronologic overview of case reports and epidemiologic studies documenting both neoplasms. This is followed by studies detailing genetic abnormalities common to both malignancies with a view to identifying unifying genetic targets for therapeutic strategies as well as to explore the possibility of a putative association and an inherited cancer susceptibility trait. From a scientific perspective, we believe we have provided evidence favoring an association between melanoma and glioma. Future studies that include documentation of additional cases, as well as a detailed molecular analyses, will lend credence to our hypothesis that the co-occurrence of these 2 conditions is likely not serendipitous.

Protocol to evaluate a pilot program to upskill clinicians in providing genetic testing for familial melanoma

INTRODUCTION

Genetic testing for hereditary cancers can improve long-term health outcomes through identifying high-risk individuals and facilitating targeted prevention and screening/surveillance. The rising demand for genetic testing exceeds the clinical genetic workforce capacity. Therefore, non-genetic specialists need to be empowered to offer genetic testing. However, it is unknown whether patient outcomes differ depending on whether genetic testing is offered by a genetics specialist or a trained non-genetics clinician. This paper describes a protocol for upskilling non-genetics clinicians to provide genetic testing, randomise high-risk individuals to receive testing from a trained clinician or a genetic counsellor, and then determine whether patient outcomes differed depending on provider-type.

METHODS

An experiential training program to upskill dermatologically-trained clinicians to offer genetic testing for familial melanoma is being piloted on 10-15 clinicians, prior to wider implementation. Training involves a workshop, comprised of a didactic learning presentation, case studies, simulated sessions, and provision of supporting documentation. Clinicians later observe a genetic counsellor led consultation before being observed leading a consultation. Both sessions are followed by debriefing with a genetic counsellor. Thereafter, clinicians independently offer genetic testing in the clinical trial. Individuals with a strong personal and/or family history of melanoma are recruited to a parallel-group trial and allocated to receive pre- and post- genetic testing consultation from a genetic counsellor, or a dermatologically-trained clinician. A mixed method approach measures psychosocial and behavioural outcomes. Longitudinal online surveys are administered at five timepoints from baseline to one year post-test disclosure. Semi-structured interviews with both patients and clinicians are qualitatively analysed.

SIGNIFICANCE

This is the first program to upskill dermatologically-trained clinicians to provide genetic testing for familial melanoma. This protocol describes the first clinical trial to compare patient-reported outcomes of genetic testing based on provider type (genetic counsellors vs trained non-genetic clinicians).

Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

Senescence under appraisal: hopes and challenges revisited

In recent years, cellular senescence has become the focus of attention in multiple areas of biomedical research. Typically defined as an irreversible cell cycle arrest accompanied by increased cellular growth, metabolic activity and by a characteristic messaging secretome, cellular senescence can impact on multiple physiological and pathological processes such as wound healing, fibrosis, cancer and ageing. These unjustly called 'zombie cells' are indeed a rich source of opportunities for innovative therapeutic development. In this review, we collate the current understanding of the process of cellular senescence and its two-faced nature, i.e. beneficial/detrimental, and reason this duality is linked to contextual aspects. We propose the senescence programme as an endogenous pro-resolving mechanism that may lead to sustained inflammation and damage when dysregulated or when senescent cells are not cleared efficiently. This pro-resolving model reconciles the paradoxical two faces of senescence by emphasising that it is the unsuccessful completion of the programme, and not senescence itself, what leads to pathology. Thus, pro-senescence therapies under the right context, may favour inflammation resolution. We also review the evidence for the multiple therapeutic approaches under development based on senescence, including its induction, prevention, clearance and the use of senolytic and senomorphic drugs. In particular, we highlight the importance of the immune system in the favourable outcome of senescence and the implications of an inefficient immune surveillance in completion of the senescent cycle. Finally, we identify and discuss a number of challenges and existing gaps to encourage and stimulate further research in this exciting and unravelled field, with the hope of promoting and accelerating the clinical success of senescence-based therapies.

Parkinson's disease and skin cancer risk: a nationwide population-based cohort study in Korea

BACKGROUND

Previous studies have reported that patients with Parkinson's disease (PD) have a significantly lower risk of cancer. Studies reporting prevalence of skin cancers in Parkinson's disease mostly involve Caucasians.

OBJECTIVE

A nationwide population-based study was conducted to determine the risk of skin cancer in patients diagnosed with PD in Korea.

METHODS

Data obtained from National Health Insurance Claims records were used to retrieve information about 70 780 patients with newly diagnosed PD between January 2010 and December 2015. The control group included 353 900 sex- and age-matched patients without PD. In this nationwide population-based cohort study, we investigated the association between PD and skin cancer.

RESULTS

The overall hazard ratio (HR) of skin cancers in patients with PD was 1.169 (95% CI, 1.005-1.359) compared with non-PD group. Among patients with PD, males aged above 65 had a 2.8-fold increase in the risk for melanoma development than the non-PD group (HR, 2.825; 95% CI, 1.395-5.721). In addition, female PD patients aged above 65 years showed a 1.3-fold increase in non-melanoma skin cancer risk than the non-PD group (HR, 1.305; 95% 1.073-1.589).

CONCLUSION

Compared with the general population, Korean patients diagnosed with PD had a greater risk of skin cancer. Especially, male patients aged 65 years and above, and diagnosed with PD had a significant risk of melanoma development compared with control.

Histologic features of melanoma associated with germline mutations of CDKN2A, CDK4, and POT1 in melanoma-prone families from the United States, Italy, and Spain

BACKGROUND

CDKN2A, CDK4, and POT1 are well-established melanoma-susceptibility genes.

OBJECTIVE

We evaluated melanoma histopathology for individuals with germline mutations of CDKN2A, CDK4, and POT1.

METHODS

We assessed histopathology for melanomas diagnosed in melanoma-prone families (≥2 individuals with melanoma) from the United States, Italy, and Spain. Comparisons between mutation carriers and noncarriers (no mutation) were adjusted for age, sex, Breslow depth, and correlations among individuals within the same family.

RESULTS

Histologic slides were evaluated for 290 melanomas (139 from 132 noncarriers, 122 from 68 CDKN2A carriers, 10 from 6 CDK4 carriers, and 19 from 16 POT1 carriers). Superficial spreading was the predominant subtype for all groups. Spitzoid morphology (>25% of tumor) was observed in 10 of 15 invasive melanomas (67%) from POT1 carriers (P < .0001 vs noncarriers). This finding was independently confirmed by 3 expert melanoma dermatopathologists in 9 of 15 invasive melanomas (60%). In situ and invasive melanomas from CDKN2A and CDK4 carriers were histologically similar to melanomas from noncarriers.

LIMITATIONS

Limited sample sizes for rare melanoma-susceptibility syndromes (CDK4, POT1).

CONCLUSION

Spitzoid morphology was associated with POT1 mutations suggesting that telomere dysfunction (POT1 mutations) may contribute to spitzoid differentiation in melanocytic tumors.

The miRNAs Role in Melanoma and in Its Resistance to Therapy

Melanoma is the less common but the most malignant skin cancer. Since the survival rate of melanoma metastasis is about 10–15%, many different studies have been carried out in order to find a more effective treatment. Although the development of target-based therapies and immunotherapeutic strategies has improved chances for patient survival, melanoma treatment still remains a big challenge for oncologists. Here, we collect recent data about the emerging role of melanoma-associated microRNAs (miRNAs) currently available treatments, and their involvement in drug resistance. We also reviewed miRNAs as prognostic factors, because of their chemical stability and resistance to RNase activity, in melanoma progression. Moreover, despite miRNAs being considered small conserved regulators with the limitation of target specificity, we outline the dual role of melanoma-associated miRNAs, as oncogenic and/or tumor suppressive factors, compared to other tumors.

Expanding the understanding of the heterogeneous nature of melanoma with bioinformatics and disorder-based proteomics

The past few decades show that incidences of melanoma are on the rise. The risk associated with this disease is an interplay between genetic and host factors and sun exposure. While scientific progress in the treatment of melanoma is remarkable, additional research is needed to improve patient outcomes and to better understand the heterogenous nature of this disease. Fortunately, as the clinical community enters the era of "big data" and personalized medicine, the rise of bioinformatics that stems from recent advances in high throughout profiling of biological information offers potential for innovative treatment options. This study aims to provide an example of the usefulness of bioinformatics and disorder-based proteomics to identify the molecular pathway in melanoma, garner information on selected proteins from this pathway and uncover their intrinsically disordered proteins regions (IDPRs) and investigate functionality implicated in these IDPRs. The present study provides a new look at the melanoma heterogeneity and suggests that, in addition to the well-established genetic heterogeneity of melanoma, there is another level of heterogeneity that lies within the conformational ensembles that stem from intrinsic disorder in melanoma-related proteins. The hope is that these insights will inspire future drug discovery campaigns.

Melanoma-Bearing Libechov Minipig (MeLiM): The Unique Swine Model of Hereditary Metastatic Melanoma

National cancer databases document that melanoma is the most aggressive and deadly cutaneous malignancy with worldwide increasing incidence in the Caucasian population. Around 10% of melanomas occur in families. Several germline mutations were identified that might help to indicate individuals at risk for preventive interventions and early disease detection. More than 50% of sporadic melanomas carry mutations in Ras/Raf/mitogen-activated protein kinase (MAPK/MEK) pathway, which may represent aims of novel targeted therapies. Despite advances in targeted therapies and immunotherapies, the outcomes in metastatic tumor are still unsatisfactory. Here, we review animal models that help our understanding of melanoma development and treatment, including non-vertebrate, mouse, swine, and other mammal models, with an emphasis on those with spontaneously developing melanoma. Special attention is paid to the melanoma-bearing Libechov minipig (MeLiM). This original swine model of hereditary metastatic melanoma enables studying biological processes underlying melanoma progression, as well as spontaneous regression. Current histological, immunohistochemical, biochemical, genetic, hematological, immunological, and skin microbiome findings in the MeLiM model are summarized, together with development of new therapeutic approaches based on tumor devitalization. The ongoing study of molecular and immunological base of spontaneous regression in MeLiM model has potential to bring new knowledge of clinical importance.

Parkinson's Disease and Melanoma: Co-Occurrence and Mechanisms

Parkinson's disease (PD) is a neurodegenerative disorder that is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta, depletion of dopamine in the striatum and the presence of Lewy bodies. Cancer is uncontrolled growth of cells in the body and migration of these cells from their site of origin to other parts of the body. PD and cancer are two opposite diseases, one arising from cell proliferation and the other from cell degeneration. This fundamental difference is consistent with inverse comorbidity between most cancers and neurodegenerative diseases. However, a positive association of PD and melanoma has been reported which has recently become of significant interest. A link between PD and cancer has been supported by many epidemiological studies, most of which show that PD patients have a lower risk of developing most cancers than the general population. However, the mechanisms underlying this epidemiological observation are not known. In this review we focus on epidemiological studies correlating PD and melanoma and the possible mechanisms underlying the co-occurrence of the two diseases. We explore possible explanations for the important observations that more PD patients develop melanoma that would otherwise be expected and vice-versa.

Variation in Cutaneous Patterns of Melanomagenesis According to Germline CDKN2A/CDK4 Status in Melanoma-Prone Families

CDKN2A and CDK4 are well-established melanoma susceptibility genes, but their effect on tumor location and distribution is unknown. We used a case-case study design to assess for differences in tumor location between mutation carriers (CDKN2A = 141 patients, 348 melanomas; CDK4 = 15 patients, 54 melanomas) and noncarriers (104 patients, 157 melanomas) in US melanoma-prone families. Associations between groups were assessed with chi-square tests. Odds ratios (ORs) for tumor location were adjusted for diagnosis age, gender, and superficial spreading subtype. Models included random effects to account for within individual and family correlations. Compared with having a truncal melanoma, CDK4 (vs. noncarriers: lower extremities OR = 14.5, 95% confidence interval [CI] = 5.02-42.0, P < 0.001; upper extremities OR = 6.88, 95% CI = 2.37-19.9, P < 0.001; head and neck OR = 18.6, 95% CI = 4.04-85.2, P < 0.001) and CDKN2A (vs. noncarriers: lower extremities OR = 3.01, 95% CI = 1.56-5.82, P < 0.05; upper extremities OR = 1.91, 95% CI = 1.03-3.52, P < 0.05; head and neck OR = 5.40, 95% CI = 2.10-13.9, P < 0.001) carriers had higher odds of developing melanoma at all other sites. Similar findings were observed for analyses stratified by gender, age, and first versus subsequent melanoma diagnoses. Further studies are needed to understand the biology underlying these genotype-associated patterns of tumor development, which could provide new insights into melanoma treatment and prevention.

Dynamic Evolution of Clonal Composition and Neoantigen Landscape in Recurrent Metastatic Melanoma with a Rare Combination of Driver Mutations

In melanoma, initiating oncogenic mutations in BRAF or NRAS are detected in premalignant lesions that accumulate additional mutations and genomic instability as the tumor evolves to the metastatic state. Here we investigate evolution of clonal composition and neoantigen landscape in an atypical melanoma displaying recurrent cutaneous lesions over a 6-year period without development of extracutaneous metastases. Whole exome sequencing of four cutaneous lesions taken during the 6-year period identified a collection of single nucleotide variants and small insertions and deletions shared among all tumors, along with progressive selection of subclones displaying fewer single nucleotide variants. Later tumors also displayed lower neoantigen burden compared to early tumors, suggesting that clonal evolution was driven, at least in part, by counter selection of subclones with high neoantigen burdens. Among the selected mutations are a missense mutation in MAP2K1 (F53Y) and an inversion on chromosome 7 generating a AKAP9-BRAF fusion. The mutant proteins cooperatively activate the MAPK signaling pathway confirming they are potential driver mutations of this tumor. We therefore describe the long-term genetic evolution of cutaneous metastatic melanoma characterized by an unexpected phenotypic stability and neoantigen-driven clonal selection.

Melanoma - role of the environment and genetics

Melanoma rates have increased in populations that are mainly European. The main etiologic factor is ultraviolet radiation, from the sun as well as artificial tanning devices. Host factors such as skin color, number of nevi, hair and eye color and tanning ability are critical factors in modifying an individual's response to the sun. Genetic factors interact with host factors and environmental factors to increase risk. This review summarizes our current knowledge of environment and genetics on melanoma risk and on gene-environment interaction.

Melanoma: Where we are and where we go

Melanoma is known as an aggressive tumor which shows an increasing incidence and poor prognosis in the metastatic phase. Hence, it seems that diagnosis and effective management (including early diagnosis, choosing of the effective therapeutic platform, caring, and training of patients for early detection) are major aspects of melanoma therapy. Early detection of melanoma is a key point for melanoma therapy. There are various diagnosis options such as assessing of biopsy, imaging techniques, and biomarkers (i.e., several proteins, polymorphism, and liquid biopsy). Among the various biomarkers, assessing circulating tumor cells, cell-free DNAs, cell-free RNAs, and microRNAs (miRNAs) have emerged as powerful diagnosis tools for melanoma patients. Deregulations of these molecules are associated with melanoma pathogenesis. After detection of melanoma, choosing of effective therapeutic regimen is a key step for recovery of melanoma patients. Several studies indicated that various therapeutic approaches including surgery, immunotherapy, systematic therapy, radiation therapy and antibodies therapy could be used as potential therapeutic candidates for melanoma therapy. Caring for melanoma patients is one of the important components of melanoma therapy. Caring and training for melanoma patients could contribute to better monitoring of patients in response to various therapeutic options. Here, we summarized various diagnosis approaches such as assessing biopsy, imaging techniques, and utilization of various biomarkers (i.e., proteins, CTCs, cfDNAs, and miRNAs) as a diagnostic biomarker for detection and monitoring patients with melanoma. Moreover, we highlighted various therapeutic options and caring aspects in patients with melanoma.

Familial melanoma-astrocytoma syndrome: synchronous diffuse astrocytoma and pleomorphic xanthoastrocytoma in a patient with germline CDKN2A/B deletion and a significant family history

Familial melanoma-astrocytoma syndrome is a tumor predisposition syndrome caused by inactivating germline alteration of the <italic>CDKN2A</italic> tumor suppressor gene on chromosome 9p21. While some families with germline <italic>CDKN2A</italic> mutations are prone to development of just melanomas, other families develop both melanomas, astrocytomas, and occasionally other nervous-system neoplasms including peripheral nerve sheath tumors and meningiomas. The histologic spectrum of the astrocytomas that arise as part of this syndrome is not well described, nor are the additional genetic alterations that drive these astrocytomas apart from the germline <italic>CDKN2A</italic> inactivation. Herein, we report the case of a young man with synchronous development of a pleomorphic xanthoastrocytoma, diffuse astrocytoma, and paraspinal mass radiographically consistent with a peripheral nerve sheath tumor. His paternal family history is significant for melanoma, glioblastoma, and oral squamous cell carcinoma. Genomic profiling revealed that he harbors a heterozygous deletion in the germline of chromosome 9p21.3 encompassing the <italic>CDKN2A</italic> and <italic>CDKN2B</italic> tumor suppressor genes. Both the pleomorphic xanthoastrocytoma and diffuse astrocytoma were found to have homozygous deletion of <italic>CDKN2A/B</italic> due to somatic loss of the other copy of chromosome 9p containing the remaining intact alleles. Additional somatic alterations included <italic>BRAF</italic> p.V600E mutation in the pleomorphic xanthoastrocytoma and <italic>PTPN11</italic>, <italic>ATRX</italic>, and <italic>NF1</italic> mutations in the diffuse astrocytoma. The presence of germline <italic>CDKN2A/B</italic> inactivation together with the presence of multiple anatomically, histologically, and genetically distinct astrocytic neoplasms, both with accompanying somatic loss of heterozygosity for the <italic>CDKN2A/B</italic> deletion, led to a diagnosis of familial melanoma-astrocytoma syndrome. This remarkable case illustrates the histologic and genetic diversity that astrocytomas arising as part of this rare glioma predisposition syndrome can demonstrate.
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A National Budget Impact Analysis of a Specialised Surveillance Programme for Individuals at Very High Risk of Melanoma in Australia

BACKGROUND

Specialised surveillance using total body photography and digital dermoscopy to monitor people at very high risk of developing a second or subsequent melanoma has been reported as cost effective.

OBJECTIVES

We aimed to estimate the 5-year healthcare budget impact of providing specialised surveillance for people at very high risk of subsequent melanoma from the perspective of the Australian healthcare system.

METHODS

A budget impact model was constructed to assess the costs of monitoring and potential savings compared with current routine care based on identification of patients at the time of a melanoma diagnosis. We used data from a published cost-effectiveness analysis of specialised surveillance, and Cancer Registry data, to estimate the patient population and healthcare costs for 2017-2021.

RESULTS

When all eligible patients, estimated at 18% of patients with melanoma diagnosed annually in Australia, received specialised surveillance rather than routine care, the cumulative 5-year cost was estimated at $93.5 million Australian dollars ($AU) ($US 64 million) for specialised surveillance compared with $AU 120.7 million ($US 82.7 million) for routine care, delivering savings of $AU 27.2 million ($US 18.6 million). With a staggered introduction of 60% of eligible patients accessing surveillance in year 1, increasing to 90% in years 4 and 5, the cumulative cost over 5 years was estimated at $AU 98.1 million ($US 67.2 million), amounting to savings of $AU 22.6 million ($US 15.5 million) compared with routine care.

CONCLUSIONS

Specialised melanoma surveillance is likely to provide substantial cost savings for the Australian healthcare system.

ATR Mutations Promote the Growth of Melanoma Tumors by Modulating the Immune Microenvironment

Melanomas accumulate a high burden of mutations that could potentially generate neoantigens, yet somehow suppress the immune response to facilitate continued growth. In this study, we identify a subset of human melanomas that have loss-of-function mutations in ATR, a kinase that recognizes and repairs UV-induced DNA damage and is required for cellular proliferation. ATR mutant tumors exhibit both the accumulation of multiple mutations and the altered expression of inflammatory genes, resulting in decreased T cell recruitment and increased recruitment of macrophages known to spur tumor invasion. Taken together, these studies identify a mechanism by which melanoma cells modulate the immune microenvironment to promote continued growth.

State of Art of Cancer Pharmacogenomics in Latin American Populations

Over the past decades, several studies have shown that tumor-related somatic and germline alterations predicts tumor prognosis, drug response and toxicity. Latin American populations present a vast geno-phenotypic diversity due to the great interethnic and interracial mixing. This genetic flow leads to the appearance of complex characteristics that allow individuals to adapt to endemic environments, such as high altitude or extreme tropical weather. These genetic changes, most of them subtle and unexplored, could establish a mutational profile to develop new pharmacogenomic therapies specific for Latin American populations. In this review, we present the current status of research on somatic and germline alterations in Latin America compared to those found in Caucasian and Asian populations.

Copy number variation in archival melanoma biopsies versus benign melanocytic lesions

BACKGROUND

Skin melanocytes can give rise to benign and malignant neoplasms. Discrimination of an early melanoma from an unusual/atypical benign nevus can represent a significant challenge. However, previous studies have shown that in contrast to benign nevi, melanoma demonstrates pervasive chromosomal aberrations.

OBJECTIVE

This substantial difference between melanoma and benign nevi can be exploited to discriminate between melanoma and benign nevi.

METHODS

Array-comparative genomic hybridization (aCGH) is an approach that can be used on DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues to assess the entire genome for the presence of changes in DNA copy number. In this study, high resolution, genome-wide single-nucleotide polymorphism (SNP) arrays were utilized to perform comprehensive and detailed analyses of recurrent copy number aberrations in 41 melanoma samples in comparison with 21 benign nevi.

RESULTS

We found statistically significant copy number gains and losses within melanoma samples. Some of the identified aberrations are previously implicated in melanoma. Moreover, novel regions of copy number alterations were identified, revealing new candidate genes potentially involved in melanoma pathogenesis.

CONCLUSIONS

Taken together, these findings can help improve melanoma diagnosis and introduce novel melanoma therapeutic targets.

Adapt, Recycle, and Move on: Proteostasis and Trafficking Mechanisms in Melanoma

Melanoma has emerged as a paradigm of a highly aggressive and plastic cancer, capable to co-opt the tumor stroma in order to adapt to the hostile microenvironment, suppress immunosurveillance mechanisms, and disseminate. In particular, oncogene- and aneuploidy-driven dysregulations of proteostasis in melanoma cells impose a rewiring of central proteostatic processes, such as the heat shock and unfolded protein responses, autophagy, and the endo-lysosomal system, to avoid proteotoxicity. Research over the past decade has indicated that alterations in key nodes of these proteostasis pathways act in conjunction with crucial oncogenic drivers to increase intrinsic adaptations of melanoma cells against proteotoxic stress, modulate the high metabolic demand of these cancer cells and the interface with other stromal cells, through the heightened release of soluble factors or exosomes. Here, we overview and discuss how key proteostasis pathways and vesicular trafficking mechanisms are turned into vital conduits of melanoma progression, by supporting cancer cell's adaptation to the microenvironment, limiting or modulating the ability to respond to therapy and fueling melanoma dissemination.

Absence of germline CDKN2A mutation in Sicilian patients with familial malignant melanoma: Could it be a population-specific genetic signature?

Germline CDKN2A mutations have been described in 25% to 40% of melanoma families from several countries. Sicilian population is genetically different from the people of Europe and Northern Italy because of its historical background, therefore familial melanoma could be due to genes different from high-penetrance CDKN2A gene. Four hundred patients with cutaneous melanoma were observed in a 6-years period at the Plastic Surgery Unit of the University of Palermo. Forty-eight patients have met the criteria of the Italian Society of Human Genetics (SIGU) for the diagnosis of familial melanoma and were screened for CDKN2A and CDK4 mutations. Mutation testing revealed that none of the families carried mutations in CDK4 and only one patient harboured the rare CDKN2A p.R87W mutation. Unlike other studies, we have not found high mutation rate of CDKN2A in patients affected by familial melanoma or multiple melanoma. This difference could be attributed to different factors, including the genetic heterogeneity of the Sicilian population. It is likely that, as in the Australian people, the inheritance of familial melanoma in this island of the Mediterranean Sea is due to intermediate/low-penetrance susceptibility genes, which, together with environmental factors (as latitude and sun exposure), could determine the occurrence of melanoma.

Recognizing melanoma: Diagnosis and treatment options

Melanoma is a malignant tumor that is usually cutaneous in origin and is associated with significant morbidity and mortality. As one of the most common cancers seen in young adults, melanoma represents a major public health concern in terms of years of lost productivity.

Risk of second primary malignancies among 1537 melanoma patients and risk of second primary melanoma among 52 354 cancer patients in Northern Italy

BACKGROUND

The number of melanoma survivors has been increasing for decades due to early diagnosis and improved survival. These patients have an increased risk of developing a second primary cancer (SPC); also, melanoma is frequently diagnosed among patients firstly diagnosed with an extracutaneous malignancy.

OBJECTIVE

We evaluated the risk of developing a SPC among 1537 melanoma patients, and the risk of second primary melanoma (SPM) in 52 354 extracutaneous cancer patients, who were treated at the European Institute of Oncology in Milan, Italy, during 2000-2010.

MATERIAL AND METHODS

We calculated standardized incidence ratios (SIR) by applying gender-, age-, year- and region-specific reference rates to the follow-up time accrued between the diagnosis of the first and the second primary malignancies.

RESULTS

Seventy-six SPC were diagnosed during a median follow-up of 4 years, of which 49 (64%) during the first 2 years upon melanoma diagnosis. The SIR was increased for cancer of breast (4.10, 95% CI 2.79-6.03), thyroid (4.67, 95% CI 1.94-11.22), brain (6.13, 95% CI 2.30-16.33) and for non-Hodgkin lymphoma (3.12, 95% CI 1.30-7.50). During a median follow-up of 4 years, 127 SPM were diagnosed: thick lesions were less frequent than for melanoma diagnosed as first cancer. The SIR was increased for cancer of breast (5.13, 95%CI 3.91-6.73), thyroid (16.2, 95%CI: 5.22-50.2), head and neck (5.62, 95%CI 1.41-22.50), soft tissue (8.68, 95%CI 2.17-34.70), cervix (12.5, 95% CI 3.14-50.20), kidney (3.19, 95%CI 1.52-6.68), prostate (4.36, 95%CI 2.63-7.24) and acute myeloid leukaemia (6.44, 95%CI 2.42-17.20).

CONCLUSIONS

The most likely causes of these associations are the clustering of lifestyle risk factors in the same subgroups of population, mainly on a sociocultural basis and surveillance bias. This raises important questions about how to best follow cancer survivors by avoiding an inefficient use of resources and an excessive medicalization of these patients' lives.

An interstitial deletion within 9p21.3 and extending beyond CDKN2A predisposes to melanoma, neural system tumours and possible haematological malignancies

Familial atypical multiple mole melanoma syndrome (FAMMM) is characterised by dysplastic naevi, malignant melanoma and pancreatic cancer. Given that large deletions involving CDKN2A (cyclin-dependent kinase inhibitor 2A) account for only 2% of cases, we describe a family that highlights the co-occurrence of both melanoma and neural system tumours to aid clinical recognition and propose a management strategy. A patient with multiple neurofibromas was referred with a provisional diagnosis of neurofibromatosis type 1 (NF1). Prior molecular testing, though, had failed to identify an NF1 mutation by sequencing and multiplex ligation-dependent probe amplification. His family history was significant for multiple in situ/malignant melanomas at young ages and several different cancers reminiscent of an underlying syndrome. A search of the Familial Cancer Database, FaCD Online, highlighted several families with cutaneous melanoma and nervous system tumours who were subsequently identified to have large deletions spanning CDKN2A Although sequencing of CDKN2A and TP53 failed to identify a mutation, a heterozygous CDKN2A deletion was identified by targeted array comparative genomic hybridisation (CGH). Whole-genome oligonucleotide array CGH and SNP analysis identified an interstitial deletion of at least 1.5 Mb within 9p21.3 and spanning approximately 25 genes. Identification of the underlying molecular abnormality permits predictive testing for at-risk relatives. Given the young cancer diagnoses, a surveillance regimen was developed and a clinical team organised for ongoing management so that genetic testing could be offered to both adults and minor children. Surveillance recommendations addressed cancer risks associated with FAMMM, and other cancers exhibited by this family with a large contiguous gene deletion.

Clinicopathological characteristics and mutation profiling in primary cutaneous melanoma

BACKGROUND

The incidence of mutations in malignant melanoma varies remarkably according to the subtype of melanoma, and this in itself is affected by racial and geographical factors. Studies screening melanoma case series for different types of mutations are relatively rare.

METHOD

The authors analyzed the frequency of various somatic point mutations of 10 genes in 106 primary cutaneous melanoma cases. The mutations (BRAF, NRAS, KIT, CDKN2A, KRAS, HRAS, PIK3CA, STK11, GNAQ, CTNNB1) were evaluated with real-time PCR-based PCR-Array through allele-specific amplification, and the results were correlated with various clinicopathological characteristics.

RESULTS

Mutations were found in 64.2% of the melanomas overall. BRAF (42.5%), NRAS (15.1%), and CDKN2A (13.2%) were the 3 most common mutations. BRAF and NRAS mutations were more frequent in nodular and superficial spreading melanomas (P < 0.001). Associations with BRAF mutation were as follows: male gender [odds ratio (OR) = 2.4], younger age (OR = 2.7), superficial spreading (OR = 15.6) and nodular melanoma (OR = 9.5), trunk localization (OR = 6.3), and intermittent sun exposure (OR = 4.6). A considerable percentage of V600K (44.4%) mutations were found among the BRAF mutations, whereas KIT mutations (3.8%) were less frequent. Multiple mutations were detected in 13.2% of the melanomas. The most common co-occurrences were in the BRAF, NRAS, and CDKN2A genes.

CONCLUSIONS

The authors analyzed 10 somatic mutations in the main subtypes of primary cutaneous melanomas from the western region of Turkey. Mutations were found in 64.2% of the melanomas overall. The most common mutations were in the BRAF and NRAS genes. In addition to other less common mutations, a notable number of multiple mutations were encountered. The multiplicity and concurrence of mutations in this study may provide further study areas for personalized targeted therapy.

Melanoma Epidemiology and Prevention

The epidemiology of melanoma is complex, and individual risk depends on sun exposure, host factors, and genetic factors, and in their interactions as well. Sun exposure can be classified as intermittent, chronic, or cumulative (overall) exposure, and each appears to have a different effect on type of melanoma. Other environmental factors, such as chemical exposures-either through occupation, atmosphere, or food-may increase risk for melanoma, and this area warrants further study. Host factors that are well known to be important are the numbers and types of nevi and the skin phenotype. Genetic factors are classified as high-penetrant genes, moderate-risk genes, or low-risk genetic polymorphisms. Subtypes of tumors, such as BRAF-mutated tumors, have different risk factors as well as different therapies. Prevention of melanoma has been attempted using various strategies in specific subpopulations, but to date optimal interventions to reduce incidence have not emerged.

Identification of a Novel Pathogenic Germline KDR Variant in Melanoma

PURPOSE

The application of pan-cancer next-generation sequencing panels in the clinical setting has facilitated the identification of low frequency somatic mutations and the testing of new therapies in solid tumors using the "basket trial" scheme. However, little consideration has been given to the relevance of nonsynonymous germline variants, which are likely to be uncovered in tumors and germline and which may be relevant to prognostication and prediction of treatment response.

EXPERIMENTAL DESIGN

We analyzed matched tumor and normal DNA from 34 melanoma patients using an Ion Torrent cancer-associated gene panel. We elected to study the germline variant Q472H in the kinase insert domain receptor (KDR), which was identified in 35% of melanoma patients in both a pilot and an independent 1,223 patient cohort. Using patient-derived melanoma cell lines and human samples, we assessed proliferation, invasion, VEGF levels, and angiogenesis by analyzing tumor microvessel density (MVD) using anti-CD34 antibody.

RESULTS

Serum VEGF levels and tumor MVD were significantly higher in Q472H versus KDR wild-type (WD) patients. Primary cultures derived from melanomas harboring the KDR variant were more proliferative and invasive than KDR wild type. Finally, using a VEGFR2 antibody, we showed that KDR Q472H cells were sensitive to targeted inhibition of VEGFR2, an effect that was not observed in KDR WT cells.

CONCLUSIONS

Our data support the integration of germline analysis into personalized treatment decision-making and suggest that patients with germline KDR variant might benefit from antiangiogenesis treatment. Clin Cancer Res; 22(10); 2377-85. ©2015 AACR.

A meta-analysis of XPC Lys939Gln polymorphism and melanoma susceptibility

BACKGROUND

It has been reported that polymorphisms of XPC Lys939Gln may affect the risk of melanom. However, the results have been inconsistent.We performed a comprehensive meta-analysis to determine the association between XPC Lys939Gln polymorphism and melanoma susceptibility.

METHODS

Based on comprehensive searches of the MEDLINE, EMBASE and ISI Web of knowledge, China National Knowledge Infrastructure (CNKI) and Wanfang Database, we identified eligible studies about the association between XPC Lys939Gln polymorphism and melanoma risk.

RESULTS

A total of 4631 cases and 5111 controls in studies were included in this meta-analysis. All studies were conducted in Caucasian populations. Allele model (Gln vs. Lys: P = 0.22; OR = 1.07, 95% CI = 0.96-1.18), and homozygous model (Gln/Gln vs. Lys/Lys: P = 0.66; OR = 1.03, 95% CI = 0.91-1.17) did not show increased risk of developing melanoma. Similarly, dominant model Gln/Gln and Gln/Lys vs. Lys/Lys: P = 0.07; OR = 1.17, 95% CI = 0.99-1.40) and recessive model (Gln/Gln vs. Gln/Lys and Lys/Lys: P = 0.67; OR = 1.03, 95% CI = 0.90-1.19) failed to show increased risk of developing melanoma.

CONCLUSION

Our pooled data suggest that there was no evidence for a major role of XPC Lys939Gln polymorphism in the pathogenesis of melanoma.

The association between Parkinson's disease and melanoma: a systematic review and meta-analysis

Objective

To assess the association between Parkinson’s disease (PD) and melanoma via systematic review and meta-analysis.

Methods

Comprehensive search in PubMed, Web of Science, Embase and four China databases (SinoMed, WanFang data, CNKI and VIP database) of epidemiologic evidences on PD and melanoma published before April 30, 2015. Studies which reported risk estimates of melanoma among PD patients or risk estimates of PD in patients with melanoma were included. Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated by random-effects models. Heterogeneity across studies was assessed using Cochran Q and I² statistics. Subgroup analyses and sensitivity analyses were conducted to evaluate sources of heterogeneity. Subgroup analyses were done according to temporal relationship, geographic region and gender respectively. We assessed publication bias using the Begg and Egger test. In addition, study appraisal was done using a scale for observational studies to ensure the quality of evidence.

Results

We identified 24 eligible studies on PD and melanoma with a total number of 292,275 PD patients: the pooled OR was 1.83 (95 % CI 1.46–2.30) overall, subgroup analyses by temporal relationship showed that risk of melanoma after PD diagnosis was significantly higher (OR 2.43, 95 % CI 1.77–3.32), but not before the diagnosis of PD (OR 1.09, 95 % CI 0.78–1.54). Subgroup analysis by geographic region showed that increased risk of melanoma in PD was found both in Europe (OR 1.44, 95 % CI 1.22–1.70) and in North America (OR 2.64, 95 % CI 1.63–4.28). Gender-specific subgroup analyses did not show difference between men (OR 1.64, 95 % CI 1.27–2.13) and women (OR 1.38, 95 % CI 1.04–1.82) in the risk of melanoma. In addition, we found the risk of non-melanoma skin cancers in PD was slightly higher (OR 1.20, 95 % CI 1.11–1.29) than general population. It was impossible to evaluate the association between PD and melanoma according to use of levodopa or gene polymorphism via meta-analysis since few observational or cohort studies have focused on it.

Conclusions

An association between PD and melanoma was confirmed. Most of the evidences were of high quality, and the conclusion was robust. Further research is needed to explore the mechanisms underlying this relationship.

Electronic supplementary material

The online version of this article (doi:10.1186/s40035-015-0044-y) contains supplementary material, which is available to authorized users.

Timing and context: important considerations in the return of genetic results to research participants

General consensus exists that clinically significant germline genetic research results should be fed back to research participants. A body of literature is emerging about Australian research participants' experiences of feedback of genetic research results and factors that influence a participant's actions after receiving such information. This exploratory qualitative study conducted interviews with 11 participants from the International Sarcoma Kindred Study, four probands and seven of their relatives. They had been informed by letter of the availability of clinically significant germline TP53 mutations identified through research. We examined the participants' views about the feedback of these genetic test results. Thematic (inductive) analysis was used to analyse the data. A number of factors influenced participants' responses following notification. This included participants' understanding of the notification letter and their perception of the relevance of the information for them and/or their family. Most notably, timing of the letter in the context of an individual's current life experiences was important. Timing and context are novel factors identified that may impact on research participants' understanding or their ability to access clinically significant research results. We outline strategies for disseminating results to research participants and their next of kin that may reduce their uncertainty around the receipt of research results.

443 paediatric cases of malignant melanoma registered with the German Central Malignant Melanoma Registry between 1983 and 2011

BACKGROUND

Malignant melanoma is a very rare paediatric tumour. This study was performed in order to understand clinical features and prognosis of malignant melanoma in children and adolescents.

METHODS

443 patients ⩽ 18 years of age with malignant melanoma were prospectively registered with the German Central Malignant Melanoma Registry between 1983 and 2011. Cases were collected from 58 participating centres. 276 paediatric cases with a follow-up >3 months were evaluated for survival probabilities and prognostic factors by Kaplan-Meier method.

RESULTS

Age of diagnosis ranged from 3 months to 18 years (median age 16 years). The male to female ratio was 0.8 (202 male, 240 female). Most melanoma were located at the trunk (n = 195) and the lower extremity (n = 114). Patients with >3 months of follow-up (median 55 months) showed an overall survival (OS) of 94.8% in 5 years. Survival according to tumour stage was 98.5% for stage I (n = 190), 91.1% for stage II (n = 39) and 53.0% for stage III/IV tumours (n = 11). Worse outcome was seen in patients with nodular melanoma (OS 77.9%, n = 42) compared to superficial spread histotype (OS 100%, n = 138) or other histotype (OS 96.9%, n = 88) (p < 0.0001), in case of thicker tumours (Clark level IV or V, OS 87.1%, n = 84) compared to thinner tumours (Clark level I, II, III, OS 99.1%, n = 164) (p = 0.0008) and in case of ulceration (OS 65.6%, n = 17) compared to no ulceration (OS 99.2%, n = 182).

CONCLUSION

Patient and tumour characteristics in paediatric melanoma patients show no evident differences to adult melanoma cases. The same clinical approach as in adults should be used.

Circulating biomarkers in malignant melanoma

Melanoma is an aggressive tumor with increasing incidence worldwide. Biomarkers are valuable tools to minimize the cost and improve efficacy of treatment of this deadly disease. Serological markers have not widely been introduced in routine clinical practice due to their insufficient diagnostic sensitivity and specificity. It is likely that the lack of objective responses with traditional treatment hinder biomarker research and development in melanoma. Recently, new drugs and therapies have, however, emerged in advanced melanoma with noticeable objective response ratio and survival. In this new scenario, serological tumor markers should be revisited. In addition, other potential circulating biomarkers such as cell-free DNA, exosomes, microRNA, and circulating tumor cells have also been identified. In this review, we summarize classical and emerging tumor markers and discuss their possible roles in emerging therapeutics.

MC1R variants increased the risk of sporadic cutaneous melanoma in darker-pigmented Caucasians: a pooled-analysis from the M-SKIP project

The MC1R gene is a key regulator of skin pigmentation. We aimed to evaluate the association between MC1R variants and the risk of sporadic cutaneous melanoma (CM) within the M-SKIP project, an international pooled-analysis on MC1R, skin cancer and phenotypic characteristics. Data included 5,160 cases and 12,119 controls from 17 studies. We calculated a summary odds ratio (SOR) for the association of each of the nine most studied MC1R variants and of variants combined with CM by using random-effects models. Stratified analysis by phenotypic characteristics were also performed. Melanoma risk increased with presence of any of the main MC1R variants: the SOR for each variant ranged from 1.47 (95%CI: 1.17-1.84) for V60L to 2.74 (1.53-4.89) for D84E. Carriers of any MC1R variant had a 66% higher risk of developing melanoma compared with wild-type subjects (SOR; 95%CI: 1.66; 1.41-1.96) and the risk attributable to MC1R variants was 28%. When taking into account phenotypic characteristics, we found that MC1R-associated melanoma risk increased only for darker-pigmented Caucasians: SOR (95%CI) was 3.14 (2.06-4.80) for subjects with no freckles, no red hair and skin Type III/IV. Our study documents the important role of all the main MC1R variants in sporadic CM and suggests that they have a direct effect on melanoma risk, independently on the phenotypic characteristics of carriers. This is of particular importance for assessing preventive strategies, which may be directed to darker-pigmented Caucasians with MC1R variants as well as to lightly pigmented, fair-skinned subjects.

Co-targeting BRAF and cyclin dependent kinases 4/6 for BRAF mutant cancers

Selective BRAF inhibitors have demonstrated significant clinical benefit in melanoma patients harboring oncogenic BRAF mutations. However, the majority of such patients either exhibit de novo resistance from the beginning of the treatment or acquire resistance and eventually relapse. Despite tremendous progress in understanding the underlying mechanisms of resistance, overcoming resistance to BRAF inhibitors remains an unmet medical need. Constitutive activation of cyclin-dependent kinases (CDK) 4/6 as a result of genetic aberrations including CDKN2A inactivation and CCND1 amplification is common across many cancer types and frequently co-occurs with oncogenic BRAF mutations. Also, cyclin D1 overexpression is a common feature of resistance to BRAF inhibitors. Here we review CDK4/6 as a therapeutic target in BRAF mutant cancers and discuss emerging evidence supporting a critical role of cyclin D1/CDK4/6 axis in de novo and acquired resistance to BRAF inhibitors. Co-targeting CDK4/6 and BRAF could be a more effective therapy to augment clinical response of BRAF inhibitors and overcome resistance in BRAF mutant cancers.

Rare presentations of primary melanoma and special populations: a systematic review

A subset of patients with melanoma present in rare and unique clinical circumstances requiring specific considerations with respect to diagnostic and therapeutic interventions. Herein, we present our review of patients with: (1) primary mucosal melanoma of the head and neck, gastrointestinal, and genitourinary tracts; (2) primary melanoma of the eye; (3) desmoplastic melanoma; (4) subungual melanoma; (5) melanoma in special populations: children, nonwhites, as well as a discussion of familial melanoma.

Prospective risk of cancer and the influence of tobacco use in carriers of the p16-Leiden germline variant

The p16-Leiden germline variant in the CDKN2A gene is associated with a high risk of melanoma and pancreatic cancer. The aims of this study were to assess the risk of developing other cancers and to determine whether tobacco use would alter cancer risk in carriers of such a variant. We therefore prospectively evaluated individuals with a p16-Leiden germline variant, participating in a pancreatic surveillance programme, for the occurrence of cancer (n=150). Tobacco use was assessed at the start of the surveillance programme. We found a significantly increased risk for melanoma (relative risk (RR) 41.3; 95% confidence interval (CI) 22.9-74.6) and pancreatic cancer (RR 80.8; 95% CI 44.7-146). In addition, increased risks were found for cancers of the lip, mouth and pharynx (RR 18.8; 95% CI 6.05-58.2) and respiratory tumours (RR 4.56; 95% CI 1.71-12.1). Current smokers developed significantly more cancers of the lip, mouth and pharynx, respiratory system and pancreas compared with former and never-smokers. In conclusion, this study shows that carriers of a p16-Leiden variant have an increased risk of developing various types of cancer, and smoking significantly increases the risk of frequently occurring cancers. Smoking cessation should be an integral part of the management of p16-Leiden variant carriers.

The CDK4/6 inhibitor LY2835219 overcomes vemurafenib resistance resulting from MAPK reactivation and cyclin D1 upregulation

B-RAF selective inhibitors, including vemurafenib, were recently developed as effective therapies for melanoma patients with B-RAF V600E mutation. However, most patients treated with vemurafenib eventually develop resistance largely due to reactivation of MAPK signaling. Inhibitors of MAPK signaling, including MEK1/2 inhibitor trametinib, failed to show significant clinical benefit in patients with acquired resistance to vemurafenib. Here, we describe that cell lines with acquired resistance to vemurafenib show reactivation of MAPK signaling and upregulation of cyclin D1 and are sensitive to inhibition of LY2835219, a selective inhibitor of cyclin-dependent kinase (CDK) 4/6. LY2835219 was demonstrated to inhibit growth of melanoma A375 tumor xenografts and delay tumor recurrence in combination with vemurafenib. Furthermore, we developed an in vivo vemurafenib-resistant model by continuous administration of vemurafenib in A375 xenografts. Consistently, we found that MAPK is reactivated and cyclin D1 is elevated in vemurafenib-resistant tumors, as well as in the resistant cell lines derived from these tumors. Importantly, LY2835219 exhibited tumor growth regression in a vemurafenib-resistant model. Mechanistic analysis revealed that LY2835219 induced apoptotic cell death in a concentration-dependent manner in vemurafenib-resistant cells whereas it primarily mediated cell-cycle G1 arrest in the parental cells. Similarly, RNAi-mediated knockdown of cyclin D1 induced significantly higher rate of apoptosis in the resistant cells than in parental cells, suggesting that elevated cyclin D1 activity is important for the survival of vemurafenib-resistant cells. Altogether, we propose that targeting cyclin D1-CDK4/6 signaling by LY2835219 is an effective strategy to overcome MAPK-mediated resistance to B-RAF inhibitors in B-RAF V600E melanoma.

A large de novo 9p21.3 deletion in a girl affected by astrocytoma and multiple melanoma

Background

Association of melanoma, neural system tumors and germ line mutations at the 9p21 region in the CDKN2A, CDKN2B and CDKN2BAS genes has been reported in a small number of families worldwide and described as a discrete syndrome in melanoma families registered as a rare disease, the melanoma–astrocytoma syndrome.

Case presentation

We here studied two young patients developing melanoma after radiotherapy for astrocytoma, both reporting lack of family history for melanoma or neural system tumors at genetic counselling. Patient A is a girl treated for anaplastic astrocytoma at 10 years and for multiple melanomas on the scalp associated to dysplastic nevi two years later. Her monozygotic twin sister carried dysplastic nevi and a slow growing, untreated cerebral lesion. Direct sequencing analysis showed no alterations in melanoma susceptibility genes including CDKN2A, CDK4, MC1R and MITF or in TP53. By microsatellite analysis, multiplex ligation-dependent probe amplification, and array comparative genomic hybridization a deletion including the CDKN2A, CDKN2B and CDKN2BAS gene cluster was detected in both twin sisters, encompassing a large region at 9p21.3 and occurring de novo after the loss of one paternal allele.

Patient B is a boy of 7 years when treated for astrocytoma then developing melanoma associated to congenital nevi on the head 10 years later: sequencing and multiplex ligation-dependent probe amplification revealed a normal profile of the CDKN2A/CDKN2B/CDKN2BAS region. Array comparative genomic hybridization confirmed the absence of deletions at 9p21.3 and failed to reveal known pathogenic copy number variations.

Conclusions

By comparison with the other germ line deletions at the CDKN2A, CDKN2B and CDKN2BAS gene cluster reported in melanoma susceptible families, the deletion detected in the two sisters is peculiar for its de novo origin and for its extension, as it represents the largest constitutive deletion at 9p21.3 region identified so far.

In addition, the two studied cases add to other evidence indicating association of melanoma with exposure to ionizing radiation and with second neoplasm after childhood cancer. Melanoma should be considered in the monitoring of pigmented lesions in young cancer patients.

Single nucleotide polymorphisms in the mitochondrial displacement loop region modifies malignant melanoma: a study in Chinese Han population

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) may be associated with an increased cancer risk. We investigated the malignant melanoma (MM) risk profile of D-loop SNPs in a case-controlled study in Chinese Han population. A statistically significant increase in SNP frequency for the T16362C, A16399G and T195C alleles was observed in MM patients (p < 0.05) comparing the MM patients to controls, which indicted that the patients who carry these alleles were susceptible to MM. The study identified SNPs in the mitochondrial D-loop could increase MM risk in Chinese Han people. The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify subgroups of patients who are at a higher risk of developing MM in Chinese Han population, thereby helping to make therapeutic decisions for these patients.

High- and low-penetrance cutaneous melanoma susceptibility genes

The aim of this review is to report the current understanding of the molecular genetics of melanoma predisposition. To date, two high-penetrance melanoma susceptibility genes, cyclin-dependent kinas inhibitor (CDKN)2A on chromosome 9p21 and cyclin-dependent kinase (CDK4) on 12q13, have been identified. Germline inactivating mutations of the CDKN2A gene are the most common cause of inherited susceptibility to melanoma. Worldwide, a few families have been found to harbor CDK4 mutations. However, predisposing alterations to familial melanoma are still unknown in a large proportion of kindreds. Other melanoma susceptibility loci have been mapped through genome-wide linkage analysis, although the putative causal genes at these loci have yet to be identified. Much ongoing research is being focused on the identification of low-penetrance melanoma susceptibility genes that confer a lower melanoma risk with more frequent variations. Specific variants of the MC1R gene have been demonstrated to confer an increase in melanoma risk. In addition, conflicting data are available on other potential low-penetrance genes encoding proteins involved in pigmentation, cell growth and differentiation, DNA repair or detoxifying of metabolites.