Melanomas arising from naevi and de novo melanomas--does origin matter?

Nevus-associated acral melanoma has lower risk of recurrence and mortality than de novo acral melanoma: A multicenter, retrospective analysis of 482 patients

BACKGROUND

It is unknown whether acral melanomas (AMs) associated with pre-existing nevi have similar risk to other AMs.

OBJECTIVE

To compare risk of recurrence and death between AMs associated with pre-existing nevi and de novo AMs.

METHODS

We conducted a multicenter retrospective cohort study involving patients diagnosed with AMs between February 2011 and November 2022.

RESULTS

About 164 patients (34.0%) had nevus-associated acral melanoma (NAAM). NAAM has lower risk of recurrence (hazard ratio: 0.69; 95% CI: 0.52-0.91; P = .008) and mortality (hazard ratio: 0.53; 95% CI: 0.37-0.76; P < .001) than de novo acral melanoma (DNAM). The 5-year recurrence-free survival (RFS) was 55.1% for NAAM compared to 42.3% for DNAM. The 5-year overall survival (OS) was 75.1% for NAAM and 63.2% for DNAM. Multivariate analyses identified Breslow thickness, nevus association, and sentinel node status as independent predictors of RFS. Age, Breslow thickness, nevus association, lymphovascular invasion, ulceration, and sentinel node status were independent predictors of OS.

LIMITATIONS

The study's limitations included its retrospective design and missing data.

CONCLUSION

Patients with nevus-associated AMs had significantly better RFS and OS compared to those with de novo AMs. Nevus association was an independent prognostic factor for both RFS and OS.

Nevi and Melanoma

Cutaneous melanoma is an aggressive form of skin cancer derived from skin melanocytes and is associated with significant morbidity and mortality. A significant fraction of melanomas are associated with precursor lesions, benign clonal proliferations of melanocytes called nevi. Nevi can be either congenital or acquired later in life. Identical oncogenic driver mutations are found in benign nevi and melanoma. While much progress has been made in our understanding of nevus formation and the molecular steps required for transformation of nevi into melanoma, the clinical diagnosis of benign versus malignant lesions remains challenging.

Clinical history analysis of Japanese melanoma cases and characteristics of melanoma with childhood onset

It remains debatable whether melanoma with a clinical history of early childhood onset truly arises from a nevus. To clarify the clinical and genetic characteristics of melanoma detected at birth or several years afterwards, 249 melanoma cases seen at Shinshu University Hospital between 2006 and 2015 were retrospectively analyzed. Ten (4.0%) cases (median age 39.5 years, range 19-70 years; male/female 2/8; lesion site, 6 extremities, 2 trunk, 1 head, 1 face; cumulative sun damage [CSD] skin, 9 low-CSD, 1 high-CSD; detection at birth 3) had recorded early childhood onset. Median Breslow's tumor thickness in those cases was 6.0 mm (range: 0.4-17.5 mm). The frequency of lesions detected at <20 years of age was significantly higher for low-CSD melanoma (17.5%) than for high-CSD (3.3%) and acral (0.8%) melanoma. Although melanoma with a history of early childhood onset is rare, the characteristics of such cases should be established since most have progressed to an advanced stage at the initial visit.

Heterogeneity in Melanoma

There is growing evidence that tumour heterogeneity has an imperative role in cancer development, evolution and resistance to therapy. Continuing advancements in biomedical research enable tumour heterogeneity to be observed and studied more critically. As one of the most heterogeneous human cancers, melanoma displays a high level of biological complexity during disease progression. However, much is still unknown regarding melanoma tumour heterogeneity, as well as the role it plays in disease progression and treatment response. This review aims to provide a concise summary of the importance of tumour heterogeneity in melanoma.

De Novo and Nevus-Associated Melanomas: Different Histopathologic Characteristics but Similar Survival Rates

The clinical significances of de novo and nevus-associated melanomas are controversial. In this study, we investigated the correlations of these forms of melanomas in respect to their pathological and clinical features and patient outcomes. The data of 660 pathologically confirmed Turkish-Caucasian melanoma patients, whose tumors were either associated with a pre-existing melanocytic nevus or not, were analyzed retrospectively. They were treated and followed up at a single tertiary referral center. A total of 440 de novo (66.7%) and 220 nevus-associated melanomas (33.3%) were enrolled into the study. The median age of the patients was 51 years. The patients consisted of 341 men (51.7%) and 319 women (48.3%). There were significant correlations between de novo melanomas and advanced age (p = 0.003), tumor thickness greater than 2 mm (p = 0.0001), ulceration (p = 0.01) and high mitotic rate (p = 0.03). On the other hand, nevus-associated melanomas were found significantly associated with histological regression (p = 0.03) and BRAFV600E mutation (p = 0.003). Most of the nevus-associated melanomas were found on trunk and head/neck, whereas extremities were more frequently inflicted by de novo melanomas (p = 0.0001). Furthermore, none of other variables, such as sex, histopathology, lymph node involvement and presence of metastasis, showed statistically significant difference between de novo and nevus-associated melanoma patients (p > 0.05). The 5-year DFS rates were 62.4% and 72.7% for de novo melanoma and for nevus-associated melanoma patients, respectively (p = 0.1). The 5-year OS rate were 72.1% and 76.4% for de novo melanoma and nevus-associated melanoma patients, respectively (p = 0.2). In conclusion, even though de novo melanomas are more significantly correlated with aggressive histopathologic variables, such as tumor depth, ulceration and high mitotic rate, the survival rates of de novo and nevus-associated melanomas are similar.

Cold atmospheric plasma generated reactive species aided inhibitory effects on human melanoma cells: an in vitro and in silico study

Malignant melanoma is considered to be a heterogeneous disease that arises from altered genes and transformed melanocytes. In this study, special softjet cold atmospheric plasma was used to treat three different human melanoma cells using air and N₂ gases to check the anti-melanoma activity. The physical effects by plasma revealed an increase in the temperature with the gradual reduction in pH at 60 sec, 180 sec and 300 sec air and N₂ plasma treatment. Cellular toxicity revealed a decreased in cell survival (~50% cell survival using air gas and <~60% cell survival using N₂ gas at 60 sec plasma treatment in G-361 cells). Gene analysis by q-PCR revealed that 3 min and 5 min air and N₂ plasma treatment activated apoptotic pathways by triggering apoptotic genes in all three melanoma cell lines. The apoptosis was confirmed by DAPI staining and its related pathways were further explored according to protein-protein docking, and their probable activation mechanism was revealed. The pathways highlighted that activation of apoptosis which leads to cellular cascades and hence stimulation ASK1 (docking method) revealed that softjet plasma can be an effective modality for human melanoma treatment.

T-Type Calcium Channels: A Potential Novel Target in Melanoma

T-type calcium channels (TTCCs) are overexpressed in several cancers. In this review, we summarize the recent advances and new insights into TTCC biology, tumor progression, and prognosis biomarker and therapeutic potential in the melanoma field. We describe a novel correlation between the Cav3.1 isoform and the increased basal autophagy in BRAFV600E-mutant melanomas and after acquired resistance to BRAF inhibitors. Indeed, TTCC blockers reduce melanoma cell viability and migration/invasion in vitro and tumor growth in mice xenografts in both BRAF-inhibitor-sensitive and -resistant scenarios. These studies open a new, promising therapeutic approach for disseminated melanoma and improved treatment in BRAFi relapsed melanomas, but further validation and clinical trials are needed for it to become a real therapeutic option.

Cutaneous melanoma associated with naevi prevalence: A 15-year cross-sectional retrospective study

BACKGROUND/OBJECTIVES

Melanoma may develop de novo or naevus associated (NAM). The exact prevalence and features of NAM are not fully elucidated.

METHODS

A 15-year cross-sectional retrospective study was performed of all melanoma cases diagnosed and treated at the skin cancer centre of the University of Naples Federico II from September 2003 to August 2018. Data collected included patient's age, gender, melanoma anatomic site, Breslow thickness, and histolopathology including melanoma-associated lesion characteristics.

RESULTS

A total of 1986 melanomas were included in the study. Based on histolopathogical examination, NAM represented 8.4% (n = 167) with de novo melanoma representing the great majority of the melanomas (91.6%). NAM was significantly more common in younger age compared to de novo melamoma (mean age 48 ± 14.9 vs 54.3 ± 15.9 years, P < 0.001), and more frequently involved the trunk (62.3% vs 51.8% P = 0.01). Mean Breslow thickness was significantly higher in de novo melanoma  compared to NAM (0.97 ± 1.48 mm vs 0.83 ± 0.95, P < 0.001). However, in situ melanoma was more commonly observed in de novo melanoma (n = 640, 35.2%) rather than NAM (n = 41, 24.5%; P < 0.01) whereas invasive melanoma represented 75.5% (n = 126) of NAM and 64.8% (n = 1179) of de novo melanoma, P < 0.01.

CONCLUSIONS

NAM represent a small percentage of melanomas (8.4%) compared to de novo melanoma. NAM appeared to be significantly more common in younger age and more frequently involved the trunk, being associated with an overall better prognosis, due to a lower mean Breslow thickness respect to de novo melanoma.

Polypoid Compound Melanocytic Proliferations: A Clinicopathological Study

Nevi can show a polypoid appearance both clinically and histologically. Anecdotally, polypoid compound melanocytic nevus may exhibit a spectrum of junctional architectural and cytologic atypia, at times creating a diagnostic challenge by mimicking the radial growth phase of melanoma. To investigate this issue, we prospectively reviewed 40 polypoid compound melanocytic proliferations without overt malignant features. The lesions frequently occurred in young female patients and were predominantly from the trunk and intertriginous areas. Commonly observed atypical features included asymmetry (30%), shouldering (47.5%), poor circumscription (37.5%), and deep extension of melanocytes along the adnexal structures (67.5%). Severe cytologic junctional atypia (22.5%), dermal mitoses (10%), and pagetoid spread of melanocytes (5%) were less commonly seen. All lesions showed a reassuring dermal component with negligible cytologic atypia and maturation with depth. Overall, 7 lesions could not be readily classified as benign nevus; 5 of these in which a benign diagnosis was strongly favored were classified as atypical polypoid compound melanocytic nevi, whereas 2 lesions with diffuse severe junctional cytologic atypia and dermal mitoses were classified as ambiguous melanocytic proliferations. Atypical/ambiguous lesions were significantly larger and predominantly located in the axilla and groin. On molecular studies, none of the lesions tested showed the molecular profile of melanoma. We confirmed that polypoid compound melanocytic nevus can exhibit a variable degree of junctional atypia, likely related to frequent episodes of trauma and regeneration resulting in melanocytic proliferation. Pathologists should be aware of this phenomenon to avoid overdiagnosis.

Malignant melanoma: Claims and controversies

Malignant melanoma is a common cancer in young people and its incidence is rising in the UK. The management of the disease is evolving, with new approaches to the treatment of locally advanced and systemic disease in particular being rapidly developed. Sentinel node biopsy is a valuable treatment option for the staging of melanoma, and completion lymphadenectomy in node-positive patients improves local disease control. However, early clearance of occult microscopic nodal disease has not been proven to confer a melanoma-specific survival advantage. Delays in the diagnosis and treatment of melanoma lead to claims being brought in negligence, but establishing causation in such cases can be difficult.

'Mind your Moles' study: protocol of a prospective cohort study of melanocytic naevi

INTRODUCTION

Having many melanocytic naevi or 'moles' on the skin is the strongest predictor of melanoma; thus, much can be learnt from investigating naevi in the general population. We aim to improve the understanding of the epidemiology and biology of naevi by conducting a 3-year prospective study of melanocytic naevi in adults.

METHODS AND ANALYSIS

This is a population-based cohort study of melanocytic naevi in 200 adults aged 20-69 years recruited via the Australian electoral roll. At baseline, participants will complete a questionnaire on their sun behaviour and health and undergo a clinical examination. Three-dimensional (3D) total-body photography will be used to record the images of skin lesions. Pigmented naevi will be analysed in terms of number, diameter, colour and border irregularity using automated analysis software (excluding scalp, beneath underwear and soles of feet). All naevi ≥5 mm will be recorded using the integrated dermoscopy photographic system. A saliva sample will be obtained at baseline for genomic DNA analysis of pigmentation, naevus and melanoma-associated genes using the Illumina HumanCoreExome platform. The sun behaviour and health follow-up questionnaire, clinical examination and 3D total-body photography will be repeated every 6 months for 3 years. The first 50 participants will also undergo manual counts of naevi ≥2 mm and ≥5 mm at baseline, 6-month and 12-month follow-ups. Microbiopsy and excision of naevi of research interest is planned to commence at the 18-month time point among those who agree to donate samples for detailed histopathological and molecular assessment.

ETHICS AND DISSEMINATION

This study was approved by the Metro South Health Human Research Ethics Committee in April 2016 (approval number: HREC/16/QPAH/125). The findings will be disseminated through peer-reviewed and non-peer-reviewed publications and presentations at conferences.

Recognition of early melanoma: a monocentric dermoscopy follow-up study comparing de novo melanoma with nevus-associated melanoma

BACKGROUND

The earlier detection of melanomas occurring within preexisting nevi is theoretically possible using sequential dermoscopy. Characterizing the early follow-up changes of nevus-associated melanomas (NAMs) and differentiating them from those observed in de novo melanomas (DNMs) may help the earlier recognition of NAMs.

METHODS

Using descriptive dermoscopic features to detect focal changes, we blindly evaluated retrospectively the baseline and follow-up images of 32 melanomas that were subsequently classified as histopathologically defined NAMs or DNMs.

RESULTS

Correlates of growth, as structureless brown‐black areas or clods, complemented each other for the identification of DNMs at baseline (structureless brown‐black areas: 66.7% DNMs, 15% NAMs, P < 0.01; combined with clods, one or the other being present: 100% DNMs, 30% NAMs, P < 0.01) and when considering their baseline presence or their appearance at follow‐up (100% DNMs, 35% NAMs, P < 0.01). Correlates of fibrosis, as white lines, when considering their baseline presence or their appearance at follow-up, were associated with NAMs (60%, 16.7% DNMs, P = 0.027).

CONCLUSION

Significant differences, distinguishing NAMs from DNMs, were detected particularly when considering both baseline signs and follow-up changes. Earlier identification of NAMs and their subsequent improved histological characterization will help define the subgroup of high-risk patients, for whom comprehensive image monitoring may be beneficial.

Melanoma Arising in a Melanocytic Nevus

The association of melanoma with a preexisting melanocytic nevus varies considerably between series, depending on whether the association is based on histological signs (4%-72%) or a clinically evident lesion (42%-85%). Histological association with a nevus correlates with favorable prognostic factors, whereas a clinical association correlates with unfavorable factors. In this review, we discuss the characteristics of nevus-associated melanoma from different perspectives: Whiteman's divergent pathway hypothesis for the development of cutaneous melanoma; and the factors involved in nevogenicity, including both the genetic and molecular factors involved in the development of the melanoma and its precursor lesions. Finally, a cumulative analysis of the 16 162 cases reported in the literature revealed that 29.8% of melanomas are histologically associated with a melanocytic nevus.

Patient-derived tumor xenograft models for melanoma drug discovery

INTRODUCTION

Cutaneous metastatic melanoma (MM) is an aggressive form of skin cancer, with treatment providing cures to a minority of patients. The multiple risk factors that contribute to MM development suggest that cutaneous melanomas embody a repertoire of altered genetic events requiring studies to better understand its biology in order to develop novel therapies.

AREAS COVERED

Patient-derived tumor xenograft (PDTX) mouse models are noted to be superior for novel drug discovery and tumor biology studies due to their ability to maintain tumor heterogeneity and their use as real-time individualized patient models. In this review, the authors highlight the utility of PDTX models in advancing treatment options for patients with MM by creating invaluable preclinical models that exhibit patient-relevant treatment outcomes.

EXPERT OPINION

There is a strong necessity to reassess current approaches in which preclinical experiments are designed and executed in order to minimize unwarranted clinical trials. With rigorously performed preclinical studies, PDTX models have the capability to effectively confirm or deny drug effective outcomes. The ability to do this, however, will demand better aids to guide experimental design, the redefining of preclinical efficacy, and the understanding that these models should be viewed as complementary to other drug prediction and efficacy tools.

Clinicopathological features and prognosis of patients with de novo versus nevus-associated melanoma in Taiwan

Studies surveying melanomas associated with melanocytic nevi in Asia are rare. In this study, we examined whether nevus-associated melanomas differ from de novo melanomas in terms of their associations with clinical factors, histologic characteristics, and patient survival in Taiwan. Using data on cancer cases obtained from the Department of Pathology archives and the Cancer Registry of National Taiwan University Hospital, we conducted a retrospective analysis of 103 consecutive melanoma patients who were diagnosed between 2010 and 2015 and received follow-up through November 2016. Approximately 17.5% of the melanomas in question were associated with a nevus. In patients under 65 years of age, non-acral lentiginous melanomas were significantly associated with a higher percentage of nevus-associated melanomas. The superficial spreading subtype, younger patient age, thinner tumor, intermittent solar exposure, and early stage were significant predictors of a melanoma being histologically associated with a nevus. The appearance of a nevus associated with a melanoma predicted better recurrence-free survival compared with de novo melanomas. Although acral lentiginous melanomas (70.9%) constituted the most common histologic subtype, only 9.6% of the acral lentiginous melanomas were associated with a nevus. Furthermore, there was no statistically significant difference between the nevus-associated and de novo acral lentiginous melanomas with regard to clinicopathological factors and survival. In conclusion, nevus-associated melanomas were uncommon among acral lentiginous melanomas. Relatedly, because over half of all melanomas in Asians are acral lentiginous melanomas, Asians are less likely than Caucasians to have nevus-associated melanomas.

Immunohistochemical analysis of T-type calcium channels in acquired melanocytic naevi and melanoma

BACKGROUND

Cutaneous malignant melanoma arises from transformed melanocytes de novo or from congenital or acquired melanocytic naevi. We have recently reported that T-type Ca²⁺ channels (TT-Cs) are upregulated in human melanoma and play an important role in cell proliferation.

OBJECTIVES

To describe for the first time in formalin-fixed paraffin-embedded tissue the immunoexpression of TT-Cs in biopsies of normal skin, acquired melanocytic naevi and melanoma, in order to evaluate their role in melanomagenesis and/or tumour progression, their utility as prognostic markers and their possible use in targeted therapies.

METHODS

Tissue samples from normal skin, melanocytic naevi and melanoma were subjected to immunohistochemistry for two TT-Cs (Cav3.1, Cav3.2); markers of proliferation (Ki67), the cell cycle (cyclin D1), hypoxia (Glut1), vascularization (CD31) and autophagy (LC3); BRAF V600E mutation (VE1) and phosphatase and tensin homologue (PTEN). Immunostaining was evaluated by histoscore. In silico analysis was used to assess the prognostic value of TT-C overexpression.

RESULTS

TT-C immunoexpression increased gradually from normal skin to common naevi, dysplastic naevi and melanoma samples, but with differences in the distribution of both isoforms. Particularly, Cav3.2 expression was significantly higher in metastatic melanoma than in primary melanoma. Statistical correlation showed a linear interaction between PTEN loss/BRAF V600E/Cav3.1/LC3/ Ki67/cyclin D1/Cav3.2/Glut1. Disease-free survival (DFS) and overall survival correlated inversely with overexpression of Cav3.2. DFS also correlated inversely with overexpression of Cav3.1.

CONCLUSIONS

TT-C immunoexpression on melanocytic neoplasms is consistent with our previous in vitro studies and appears to be related to tumour progression. TT-C upregulation can be considered as a prognostic marker using The Cancer Genome Atlas database. The high expression of Cav3.2 in metastatic melanoma encourages the investigation of the use of TT-C blockers in targeted therapies.

Higher Nevus Count Exhibits a Distinct DNA Methylation Signature in Healthy Human Skin: Implications for Melanoma

High nevus count is the strongest risk factor for melanoma, and although gene variants have been discovered for both traits, epigenetic variation is unexplored. We investigated 322 healthy human skin DNA methylomes associated with total body nevi count, incorporating genetic and transcriptomic variation. DNA methylation changes were identified at genes involved in melanocyte biology, such as RAF1 (P = 1.2 × 10^-6) and CTC1 (region: P = 6.3 × 10^-4), and other genes including ARRDC1 (P = 3.1 × 10^-7). A subset exhibited coordinated methylation and transcription changes within the same biopsy. The total analysis was also enriched for melanoma-associated DNA methylation variation (P = 6.33 × 10^-6). In addition, we show that skin DNA methylation is associated in cis with known genome-wide association study single nucleotide polymorphisms for nevus count, at PLA2G6 (P = 1.7 × 10^-49) and NID1 (P = 6.4 × 10^-14), as well as melanoma risk, including in or near MC1R, MX2, and TERT/CLPTM1L (P < 1 × 10^-10). Our analysis using a uniquely large dataset comprising healthy skin DNA methylomes identified known and additional regulatory loci and pathways in nevi and melanoma biology. This integrative study improves our understanding of predisposition to nevi and their potential contribution to melanoma pathogenesis.

De Novo vs Nevus-Associated Melanomas: Differences in Associations With Prognostic Indicators and Survival

BACKGROUND

Although 20% to 30% of melanomas are histopathologically 'nevus associated,' the majority of melanomas arise de novo, ie, in clinically normal skin with no associated nevus. We examined whether these forms of melanoma differed in their associations with clinical and histopathologic features and patient survival.

METHODS

We analyzed two prospective cohorts from our institution with protocol-driven follow-up information (NYU1, n = 1024; NYU2, n = 1125). We used univariate and multivariable analyses to examine associations between de novo vs nevus-associated melanoma classification and age, anatomic site, tumor thickness, tumor ulceration, mitotic index, histological subtype, clinical stage, and survival. We tested the associations identified in NYU1 using NYU2 as a replication cohort. All tests of statistical significance were two-sided.

RESULTS

In NYU1, de novo melanomas were associated with tumor thickness greater than 1.0 mm (odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.43 to 2.70, P < .001), ulceration (OR = 1.65, 95% CI = 1.10 to 2.54, P = .02), nodular subtype (OR = 3.26, 95% CI = 1.70 to 7.11, P = .001), greater than stage I (OR = 2.35, 95% CI = 1.65 to 3.40, P < .001), older age (OR = 1.64, 95% CI = 1.18 to 2.30, P = .004), and shorter overall survival (HR = 1.63, 95% CI = 1.22 to 2.18, P < .001). In NYU2, de novo melanoma was again statistically significantly associated with thickness greater than 1.0 mm (OR = 2.24, 95% CI = 1.72 to 2.93, P < .001), ulceration (OR = 2.88, 95% CI = 1.95 to 4.37, P < .001), nodular subtype (OR = 2.41, 95% CI = 1.75 to 3.37, P < .001), greater than stage I (OR = 2.42, 95% CI = 1.80 to 3.29, P < .001), older age (OR = 1.68, 95% CI = 1.31 to 2.17, P < .001), and shorter overall survival (HR = 2.52, 95% CI = 1.78 to 3.56, P < .001). In multivariable analysis, de novo classification was an independent, poor prognostic indicator in NYU2 (HR = 1.70, 95% CI = 1.19 to 2.44, P = .004). Male patients had a statistically significantly worse survival than female patients if their melanoma was de novo (NYU1, P < .001; NYU2, P < .001); unexpectedly, there was no sex difference in survival among patients with nevus-associated tumors.

CONCLUSIONS

These data suggest that de novo melanomas are more aggressive than nevus-associated melanomas. This classification scheme may also provide a useful framework for investigations into sex differences in melanoma outcomes.

Loss of the epigenetic mark, 5-Hydroxymethylcytosine, correlates with small cell/nevoid subpopulations and assists in microstaging of human melanoma

Melanomas in the vertical growth phase (VGP) not infrequently demonstrate cellular heterogeneity. One commonly encountered subpopulation displays small cell/nevoid morphology. Although its significance remains unknown, such subpopulations may pose diagnostic issues when faced with differentiating such changes from associated nevus or mistaking such regions for nevic maturation (pseudomaturation). That 'loss' of the epigenetic biomarker, 5-hydroxymethylcytosine (5-hmC), is a hallmark for melanoma and correlates with virulence prompted us to explore the diagnostic utility and biological implications of 5-hmC immunohistochemistry (IHC) in melanomas with small cell/nevoid subpopulations. Fifty-two cases were included in this study, including melanomas with small cell/nevoid subpopulations (MSCN) or melanomas with pre-existing nevus (MPEN). Semiquantitative and computer-validated immunohistochemical analyses revealed invariable, uniform loss of 5-hmC in the conventional melanoma component. By contrast, the nevic components in MPEN cases demonstrated strong nuclear immunopositivity. In MSCN cases, there was partial to complete loss of 5-hmC restricted to these nevoid areas. Based on recent data supporting tight correlation between 5-hmC loss and malignancy, our findings indicate a potential 'intermediate' biological nature for small cell/nevoid subpopulations. Because 5-hmC assisted in differentiating such regions from associated nevus, the use of 5-hmC as an adjunct to microstaging in difficult cases showing VGP heterogeneity should be further explored.

Skin cancer in rural workers: nursing knowledge and intervention

OBJECTIVETo identify the exposure of rural workers to the sun's ultraviolet radiation and pesticides; to identify previous cases of skin cancer; and to implement clinical and communicative nursing actions among rural workers with a previous diagnosis of skin cancer.METHODObservational-exploratory study conducted with rural workers exposed to ultraviolet radiation and pesticides in a rural area in the extreme south of Brazil. A clinical judgment and risk communication model properly adapted was used to develop interventions among workers with a previous history of skin cancer.RESULTSA total of 123 (97.7%) workers were identified under conditions of exposure to the sun's ultraviolet radiation and pesticides; seven (5.4%) were identified with a previous diagnosis of skin cancer; four (57.1%) of these presented potential skin cancer lesions.CONCLUSIONThis study's results enabled clarifying the combination of clinical knowledge and risk communication regarding skin cancer to rural workers.

Mutational status of naevus-associated melanomas

BACKGROUND

The origin of melanoma has always been a debated subject, as well as the role of adjacent melanocytic naevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a naevus.

OBJECTIVES

To evaluate the presence of mutations in genes from well-known melanomagenesis pathways in a large series of naevus-associated melanomas.

MATERIALS AND METHODS

Sixty-one melanomas found in association with a pre-existing naevus were microdissected, after careful selection of cell subpopulations, and submitted to Sanger sequencing of the BRAF, NRAS, c-KIT, PPP6C, STK19 and RAC1 genes. Each gene was evaluated twice in all samples by sequencing or by sequencing and another confirmation method, allele-specific fluorescent polymerase chain reaction (PCR) and capillary electrophoresis detection or by SNaPshot analysis. Only mutations confirmed via two different molecular methods or twice by sequencing were considered positive.

RESULTS

The majority of cases presented concordance of mutational status between melanoma and the associated naevus for all six genes (40 of 60; 66.7%). Nine cases presented concomitant BRAF and NRAS mutations, including one case in which both the melanoma and the adjacent naevus harboured V600E and Q61K double mutations. In two cases, both melanoma and associated naevus located on acral sites were BRAF mutated, including an acral lentiginous melanoma.

CONCLUSIONS

To our knowledge this is the largest naevus-associated melanoma series evaluated molecularly. The majority of melanomas and adjacent naevi in our sample share the same mutational profile, corroborating the theory that the adjacent naevus and melanoma are clonally related and that the melanoma originated within a naevus.

Nevus-Associated versus de novo Melanoma: Do They Have Different Characteristics and Prognoses?

Aim

The aim of this study was to determine if nevus-associated melanoma differs in characteristics and prognosis from de novo melanoma.

Patients and Methods

The study included 118 melanoma patients. Clinical findings were retrospectively evaluated. For histopathological parameters, HE sections were reexamined. The differentiation between de novo and nevus-associated melanoma was based on the histopathological evidence of a precursor nevus. In addition, all analyses were repeated in all cases in which nevus-associated melanoma was defined based on patient anamnesis.

Results

Among all patients, 28 (23.7%) had nevus-associated melanoma. Nevus-associated melanoma was most commonly located on the extremities (50%), followed by the trunk (25%), whereas de novo melanoma was most commonly located in the head and neck region (32.2%), followed by the acral region (31.1%). Other clinical findings and histopathological parameters did not differ significantly between the two groups (p > 0.05). The findings remained consistent following the repeated analysis of all cases in which nevus-associated melanoma was defined based on patient anamnesis.

Conclusions

Nevus-associated melanoma was most commonly located on the extremities and the trunk, whereas de novo melanoma was most commonly located in the head and neck and the acral region. Furthermore, nevus-associated melanoma was similar to de novo melanoma in terms of prognosis and other disease characteristics.

Calcium channel expression and applicability as targeted therapies in melanoma

The remodeling of Ca(2+) signaling is a common finding in cancer pathophysiology serving the purpose of facilitating proliferation, migration, or survival of cancer cells subjected to stressful conditions. One particular facet of these adaptive changes is the alteration of Ca(2+) fluxes through the plasma membrane, as described in several studies. In this review, we summarize the current knowledge about the expression of different Ca(2+) channels in the plasma membrane of melanoma cells and its impact on oncogenic Ca(2+) signaling. In the last few years, new molecular components of Ca(2+) influx pathways have been identified in melanoma cells. In addition, new links between Ca(2+) homeostasis and specific cell processes important in melanoma tumor progression have been unveiled. Thus, not only do Ca(2+) channels appear to have a potential as prognostic markers, but their pharmacological blockade or gene silencing is hinted as interesting therapeutic approaches.

Melanocytic naevi with globular and reticular dermoscopic patterns display distinct BRAF V600E expression profiles and histopathological patterns

BACKGROUND

BRAF (v-raf murine sarcoma viral oncogene homologue B) V600E mutations have been detected with high frequency in melanocytic naevi. Few studies have stratified analyses by naevus dermoscopic pattern.

OBJECTIVES

To determine the frequency of BRAF V600E expression and histopathological pattern in acquired melanocytic naevi distinguished by a globular vs. reticular dermoscopic pattern.

METHODS

We retrospectively identified histologically proven melanocytic naevi with banal reticular or globular dermoscopic patterns and evaluated BRAF V600E expression using immunohistochemistry.

RESULTS

BRAF V600E expression was detected in 11 of 12 globular naevi vs. four of 13 reticular naevi (91·7% vs. 30·1%, P = 0·004). A predominantly dermal growth pattern (P < 0·001) and the presence of large junctional nests (P = 0·017) were each associated with a globular dermoscopic pattern. The presence of either a predominantly dermal growth pattern or large junctional nests was found in 13 of 15 naevi positive for BRAF V600E and in two of 10 naevi negative for BRAF V600E (86·7% vs. 20%, P = 0·002).

CONCLUSIONS

The frequency of BRAF V600E mutations differs in naevi distinguished by unique dermoscopic structures and microanatomical growth patterns. Globular naevi, which most often histologically correspond to a predominantly dermal growth pattern and/or the presence of large junctional nests, are significantly more likely to express BRAF V600E than reticular naevi. These preliminary results require validation, but may directly inform future studies of naevogenesis and melanoma genesis.

Nevus-associated melanomas: clinicopathologic features

OBJECTIVES

The clinical significance of nevus-associated melanoma compared with de novo melanomas remains controversial. It has been suggested that nevus-associated melanomas have a higher Breslow thickness and therefore worse prognosis. Over a 10-year period, this study evaluated the incidence of nevus-associated melanoma and its prognostic significance related to clinicopathologic features.

METHODS

Cross-sectional study from 1995 through 2004 in a dermatopathology referral center. With available data, we evaluated sex, primary location, histologic subtype, Breslow thickness, Clark level, presence of ulceration, associated lesion, and histologic subtype of the associated lesion.

RESULTS

Of 135,653 pathologic records from skin biopsy specimens over a 10-year period, 1,190 melanoma records were selected. Nevus-associated melanomas corresponded to 390 (32.8%) melanomas, with thin melanomas having a nevus 1.52 times the association observed with thick melanomas (>1.01 mm; 95% confidence interval, 1.16-1.99; P < .001). Superficial spreading melanoma was the most frequent, while no lentigo maligna melanoma was associated with nevi. The median Breslow thickness of nevus-associated melanomas was lower than that of de novo melanomas.

CONCLUSIONS

Nevus-associated melanomas, which represent one-third of the melanomas in southeast Brazil, are associated with intermittent sun exposure, superficial spreading melanomas, and lower Breslow thickness. This is one of the largest series describing nevus-associated melanomas in Latin America.

Promoter CpG island hypermethylation in dysplastic nevus and melanoma: CLDN11 as an epigenetic biomarker for malignancy

Dysplastic nevi are melanocytic lesions that represent an intermediate stage between common nevus and melanoma. Histopathological distinction of dysplastic nevus from melanoma can be challenging and there is a requirement for molecular diagnostic markers. In this study, we examined promoter CpG island methylation of a selected panel of genes, identified in a genome-wide methylation screen, across a spectrum of 405 melanocytic neoplasms. Promoter methylation analysis in common nevi, dysplastic nevi, primary melanomas, and metastatic melanomas demonstrated progressive epigenetic deregulation. Dysplastic nevi were affected by promoter methylation of genes that are frequently methylated in melanoma but not in common nevi. We assessed the diagnostic value of the methylation status of five genes in distinguishing primary melanoma from dysplastic nevus. In particular, CLDN11 promoter methylation was specific for melanoma, as it occurred in 50% of primary melanomas but in only 3% of dysplastic nevi. A diagnostic algorithm that incorporates methylation of the CLDN11, CDH11, PPP1R3C, MAPK13, and GNMT genes was validated in an independent sample set and helped distinguish melanoma from dysplastic nevus (area under the curve 0.81). Melanoma-specific methylation of these genes supports the utility as epigenetic biomarkers and could point to their significance in melanoma development.

T-type calcium channel blockers inhibit autophagy and promote apoptosis of malignant melanoma cells

We have recently reported that human melanoma cells express a variety of voltage-gated calcium (Ca(2+) ) channel types, including low-voltage-activated T-type channels that play a significant role in melanoma cell cycle progression. Here, we challenged melanoma metastatic cells with T-type channel blockers of clinical use and found a dual effect on cell viability: (i) a reduction in the proliferation rate, through a halt in the progression to the G1 -S phase; and (ii) a promotion of cell death that was partially dependent on the activation of caspases. An in-depth analysis of the death process showed that the apoptotic pathway is preceded by endoplasmic reticulum stress and the subsequent inhibition of the basal macroautophagy which is active in these cells. The effects of pharmacological blockers on Ca(2+) homeostasis, autophagy, and cell death were mimicked by T-type channel gene silencing. These results provide the basis for a new pharmacological and/or gene silencing approach toward tackling melanoma metastasis.

Merlin is a negative regulator of human melanoma growth

Merlin is encoded by the neurofibromatosis type 2 (NF2) gene and is a member of the Band 4.1 protein family. This protein acts as a linker that connects cell surface proteins to the actin cytoskeleton. Defects caused by mutations of the NF2 gene give rise to NF2 disease, which is generally characterized by the formation of bilateral vestibular schwannomas and, to a lesser extent, meningiomas and ependymomas. In addition to these tumor types, NF2 is mutated and/or merlin expression is reduced or lost in numerous non-NF2 associated tumors, including melanoma. However, the role of merlin in human melanoma growth and the mechanism underlying its effect are currently unknown. In the present study, we show that merlin knockdown enhances melanoma cell proliferation, migration, and invasion in vitro and that decreased merlin expression promotes subcutaneous melanoma growth in immunocompromised mice. Concordantly, we find that increased expression of merlin in a metastatic melanoma cell line reduced their in vitro migration and proliferation, and diminished their ability to grow in an anchorage independent manner. Increased merlin expression also inhibits in vivo growth of these melanoma cells. Lastly, we demonstrate that higher merlin levels in human melanoma cells promote the H₂O₂-induced activation of MST1/2 Ser/Thr kinases, which are known tumor suppressors in the Hippo signaling pathway. Taken together, these results provide for the first time evidence that merlin negatively regulates human melanoma growth, and that loss of merlin, or impaired merlin function, results in an opposite effect. In addition, we show that increased merlin expression leads to enhanced activation of the MTS1/2 kinases, implying the potential roles of MST1/2 in mediating the anti-melanoma effects of merlin.

Benefits of total body photography and digital dermatoscopy ("two-step method of digital follow-up") in the early diagnosis of melanoma in patients at high risk for melanoma

BACKGROUND

Early detection of melanoma is the best way to improve prognosis. Digital follow-up (DFU) programs of populations at high risk could be an efficient strategy for detecting early melanomas with low morbidity.

OBJECTIVE

We sought to report the added value of the use of the "two-step method" (digital total body photography and digital dermatoscopy).

METHODS

This was an analysis of the surveillance of 618 patients at high risk for melanoma included in our DFU program from 1999 to 2008.

RESULTS

A total of 11,396 lesions were monitored (mean 18.44/patient) during a median follow-up of 96 months (median 10 visits/patient). A total of 1152 lesions, 1.86 per patient, were excised. Almost 70% (798) were lesions previously registered at least twice, whereas 356 (30%) were detected and removed in the same visit. During follow-up, 98 melanomas (8.5% of excised lesions) were diagnosed in 78 patients (12.6%). In all, 53 melanomas were in situ (53.3%), whereas invasive (45) showed a Breslow index of less than 1 mm (median 0.5 mm) and none were ulcerated.

LIMITATIONS

Because there are no control groups we cannot determine if the combined use of total body photography and digital dermatoscopy is more beneficial than these techniques used separately.

CONCLUSION

DFU with total body photography and dermatoscopy in a selected population at high risk demonstrated the early detection of melanomas with a low rate of excisions. Long-term follow-up is required to allow the detection of slow-growing melanomas. Based on our 10-year experience, melanomas can be diagnosed at any time, suggesting that in a population at high risk for melanoma, DFU should be maintained over time.

Extrafollicular dermal melanocyte stem cells and melanoma

Recent studies suggest that extrafollicular dermal melanocyte stem cells (MSCs) persist after birth in the superficial nerve sheath of peripheral nerves and give rise to migratory melanocyte precursors when replacements for epidermal melanocytes are needed on the basal epidermal layer of the skin. If a damaged MSC or melanocyte precursor can be shown to be the primary origin of melanoma, targeted identification and eradication of it by antibody-based therapies will be the best method to treat melanoma and a very effective way to prevent its recurrence. Transcription factors and signaling pathways involved in MSC self-renewal, expansion and differentiation are reviewed. A model is presented to show how the detrimental effects of long-term UVA/UVB radiation on DNA and repair mechanisms in MSCs convert them to melanoma stem cells. Zebrafish have many advantages for investigating the role of MSCs in the development of melanoma. The signaling pathways regulating the development of MSCs in zebrafish are very similar to those found in humans and mice. The ability to easily manipulate the MSC population makes zebrafish an excellent model for studying how damage to MSCs may lead to melanoma.

Characterization of 1152 lesions excised over 10 years using total-body photography and digital dermatoscopy in the surveillance of patients at high risk for melanoma

BACKGROUND

The combined use of total-body photography and digital dermatoscopy, named "two-step method of digital follow-up," allowed the detection of incipient melanoma as a result of dermatoscopic or macroscopic changes during follow-up.

OBJECTIVE

We sought to assess dermatoscopic features and dynamic changes leading to excision of melanocytic lesions during our 10-year experience of monitoring patients at high risk for melanoma.

METHODS

We analyzed 1152 lesions excised during the surveillance of 618 patients at high risk for melanoma from 1999 to 2008.

RESULTS

A total of 779 excised lesions had been previously recorded: 728 were removed because of dermatoscopic changes during follow-up and 51 were removed even though no significant change was noted. The remaining 373 excised lesions were new or undetected on previous total-body photography. A total of 98 melanomas were detected, 60 in the monitored lesions, and 38 among the "new" lesions. The most frequent dermatoscopic changes detected were asymmetric enlargement in almost 60% (n = 418), focal changes in structure in 197 (27%) and in pigmentation in 122 (17%), the latter two being more frequently seen in melanomas than in nevi (both P < .001). No significant differences were detected between dermatoscopic or histopathological characteristics of the melanomas in each group, with a considerable proportion of melanomas misclassified as benign in both groups (26.3% and 38.3%, respectively).

LIMITATIONS

The dermatoscopy pattern of stable lesions and the histopathology of lesions not removed were not included in the study.

CONCLUSION

The most frequent dermatoscopic features associated with melanoma were focal change in pigmentation or structure. Melanomas detected by dermatoscopic changes were remarkably similar to those detected in total-body photography. Almost 40% of melanomas diagnosed in individuals at high risk corresponded to lesions that were not under dermatoscopic surveillance.

RAS/RAF/MEK/ERK and PI3K/PTEN/AKT Signaling in Malignant Melanoma Progression and Therapy

Cutaneous malignant melanoma is one of the most serious skin cancers and is highly invasive and markedly resistant to conventional therapy. Melanomagenesis is initially triggered by environmental agents including ultraviolet (UV), which induces genetic/epigenetic alterations in the chromosomes of melanocytes. In human melanomas, the RAS/RAF/MEK/ERK (MAPK) and the PI3K/PTEN/AKT (AKT) signaling pathways are two major signaling pathways and are constitutively activated through genetic alterations. Mutations of RAF, RAS, and PTEN contribute to antiapoptosis, abnormal proliferation, angiogenesis, and invasion for melanoma development and progression. To find better approaches to therapies for patients, understanding these MAPK and AKT signaling mechanisms of melanoma development and progression is important. Here, we review MAPK and AKT signaling networks associated with melanoma development and progression.

A decade of melanomas: identification of factors associated with delayed detection in an academic group practice

BACKGROUND

Melanoma incidence is increasing, but the effect of various clinical factors on tumor stage is unclear.

OBJECTIVE

To review histologic and clinical features of melanomas diagnosed in our group over a 10-year period to determine trends in diagnosis and lesion derivation, predictive value of clinical lesion size, and effect of physician and patient concerns before biopsy.

METHOD

Relevant pathology reports and physician clinic notes were reviewed for 572 melanomas.

RESULT

From 1999 to 2008, melanoma biopsies increased significantly more than nevus biopsies and patient visits. Melanomas predominantly (81%) arose de novo, with remaining lesions as likely to arise from common as dysplastic nevi. Melanomas were detected at twice the rate, and at earlier stage, in established as in new patients. Clinical size of invasive melanomas was related to lesion depth. For 64% of melanomas, patient and physician concern drove the decision to biopsy, whereas 1.4% of melanomas were biopsied only for patient concern.

CONCLUSION

The increase in melanoma diagnoses was largely due to increases in cases of lentigo maligna on the head and neck. Delayed detection was associated with location on trunk and extremities, new patient status, patient concern before biopsy, and physician suspicion of nonmelanoma skin cancer.

p53 prevents progression of nevi to melanoma predominantly through cell cycle regulation

p53 is the central member of a critical tumor suppressor pathway in virtually all tumor types, where it is silenced mainly by missense mutations. In melanoma, p53 predominantly remains wild type, thus its role has been neglected. To study the effect of p53 on melanocyte function and melanomagenesis, we crossed the ‘high-p53’Mdm4+/− mouse to the well-established TP-ras0/+ murine melanoma progression model. After treatment with the carcinogen dimethylbenzanthracene (DMBA), TP-ras0/+ mice on the Mdm4+/− background developed fewer tumors with a delay in the age of onset of melanomas compared to TP-ras0/+ mice. Furthermore, we observed a dramatic decrease in tumor growth, lack of metastasis with increased survival of TP-ras0/+: Mdm4+/− mice. Thus, p53 effectively prevented the conversion of small benign tumors to malignant and metastatic melanoma. p53 activation in cultured primary melanocyte and melanoma cell lines using Nutlin-3, a specific Mdm2 antagonist, supported these findings. Moreover, global gene expression and network analysis of Nutlin-3-treated primary human melanocytes indicated that cell cycle regulation through the p21WAF1/CIP1 signaling network may be the key anti-melanomagenic activity of p53.

Progress in understanding melanoma propagation

Melanoma, like most cancers, is a disease that wreaks havoc mostly through its propensity to spread and establish secondary tumors at sites that are anatomically distant from the primary tumor. The consideration of models of cancer progression is therefore important to understand the essence of this disease. Previous work has suggested that melanoma may propagate according to a cancer stem cell (CSC) model in which rare tumorigenic and bulk non-tumorigenic cells are organized into stable hierarchies within tumors. However, recent studies using assays that are more permissive for revealing tumorigenic potential indicate that it will not be possible to cure patients by focusing research and therapy on rare populations of cells within melanoma tumors. Studies of the nature of tumorigenic melanoma cells reveal that these cells may gain a growth, metastasis and/or therapy resistance advantage by acquiring new genetic mutations and by reversible epigenetic mechanisms. In this light, efforts to link the phenotypes, genotypes and epigenotypes of melanoma cells with differences in their in vivo malignant potential provide the greatest hope of advancing the exciting progress finally being made against this disease.

Effects of ultraviolet A on the activity of two metabolic enzymes, DNA damage and lipid peroxidation during early developmental stages of the African catfish, Clarias gariepinus (Burchell, 1822)

Many ultraviolet-A (UVA)-induced biochemical and physiological changes are valid as biomarkers using aquatic species for detection of the degree of stress. Changes in the concentration and activities of enzymes, such as glucose-6-phosphate dehyderogenase (G6PDH), lactate dehyderogenase (LDH), DNA damage and lipid peroxidation (LPO), can be used as biomarkers to identify possible environmental contamination in fish. This study aimed to investigate the impact of UVA on the activity of the selected enzymes, DNA damage and LPO during early developmental stages of the African catfish Clarias gariepinus. Embryo hemogenates were used for measurements of G6PDH, LDH, DNA damage and LPO concentrations and activities spectrophotometrically at 37 degrees C. The normal ontogenetic variations in enzyme activities, DNA damage and LPO of the early developmental stages (24-168 h-PFS; hours-post fertilization stage) were studied. There was a significant decrease in the activity of G6PDH till 120 h-PFS. Then after 120 h-PFS, the activity of such enzymes insignificantly increased toward higher stages. The LDH activity was recorded with a pattern of decrease till 96 h-PFS, followed by a significant increase toward 168 h-PFS. The polynomial pattern of variations in DNA damage and LPO was also evident. The patterns of the enzyme activities, corresponding DNA damage and LPO of the early ontogenetic stages under the influence of three different UVA doses (15, 30 and 60 min), were recorded. The pattern of variations in G6PDH activity in UVA-induced groups was similar to that of the control group with variation in the magnitude of such activity. In all treated groups, LDH activity decreased till 96 h-PFS, then increased till 168 h-PFS. Within each of the embryonic stages, the increase in UVA led to a significant increase in DNA damage. A significant increase in lipid peroxidation under UVA doses was recorded. The variability in number and molecular weight of proteins under exposure to UVA was evident, reflecting some of the genetic and transcriptional changes during exposure and development.

Comparative analysis of total body and dermatoscopic photographic monitoring of nevi in similar patient populations at risk for cutaneous melanoma

BACKGROUND

Our previous experience monitoring nevi in high-risk patients using serial digital epiluminescence microscopy (DELM) photography achieved low biopsy rates but was limited by melanomas presenting as new lesions or arising from nevi that had not been photographed.

OBJECTIVE

To determine whether biopsy rates, efficiency of melanoma detection, and melanoma origin (de novo vs nevus derived) differed in a similar patient population monitored using total body (TB) photography.

METHODS

One thousand seventy-six patients (including 187 from a prior cohort) underwent TB photography and were monitored using photographs obtained at the initial visit. Risk factors and median monitoring periods for these patients were comparable with those of patients previously monitored using DELM photography.

RESULTS

Two hundred seventy-five biopsies were performed in 467 patients on follow-up visits. Of 12 melanomas detected on follow-up, five were invasive, five presented as changing lesions and two as new lesions, nine arose de novo, and the remainder were nevus derived.

CONCLUSIONS

In our experience with both approaches, monitoring patients at risk for melanoma using TB photography was associated with lower biopsy rates and lower nevus-to-melanoma ratios than using DELM and facilitated detection of new and changing lesions. In both cohorts, the majority of melanomas detected on follow-up arose de novo.

A novel mouse model for de novo Melanoma

Nevus-associated melanomas arise from pre-existing benign lesions, but de novo melanomas can also develop in the absence of such lesions. Few studies have addressed the latter phenomenon because no animal models have been described in which melanomas clearly develop in a de novo manner. In this study, we have address this need in defining RFP-RET-transgenic mice (RET mice) as a mouse model for multi-step melanomagenesis that proceeds via tumor-free, benign, premalignant, and malignant stages. Melanomas from RET mice exhibited decreased expression levels of endothelin receptor B (Ednrb) compared with benign tumors. In RET mice that were heterozygous for Ednrb (Ednrb+/-;RET mice), >80% of the arising primary tumors were malignant. Life span after tumor development in the mice was significantly shorter than in RET mice. Lung metastasis after tumor development was significantly higher than in RET mice. The observed process of melanomagenesis in Ednrb+/-;RET mice, which proceeded without a pre-existing benign lesion, along with the emergent characteristics in the model after tumor development corresponded well with the formation of de novo melanoma in humans. Our findings define a novel transgenic mouse model for de novo melanoma and suggest that reduced expression of Ednrb might facilitate the development of de novo melanoma in humans.

The role of ultraviolet radiation in melanomagenesis

The role of ultraviolet radiation (UV) in the pathogenesis has been discussed controversially for many decades. Studies in mice (SCID, HGF/SF, SV40T) which develop malignant melanoma, show a role of UVB in melanomagenesis. In contrast to this, the role of UVA is less clear. We will review the recent in vitro and in vivo data in support of the hypothesis that UVA is also involved in the development of malignant melanoma. The role of UVA in p53 activation, apoptosis, cell cycle arrest and photoproduct formation is discussed.

Strategies for early melanoma detection: Approaches to the patient with nevi

Given its propensity to metastasize and the lack of effective therapies for most patients with advanced disease, early detection of melanoma is a clinical imperative. Although there are no noninvasive techniques for the definitive diagnosis of melanoma, and the "gold standard" remains biopsy with histologic examination, a variety of modalities may facilitate early melanoma diagnosis and the detection of new and changing nevi. This article reviews the general clinical principles of early melanoma detection and various modalities that are currently available or on the horizon, providing the clinician with an up to date understanding of management strategies for their patients with numerous or atypical nevi.

LEARNING OBJECTIVE

After completing this learning activity, participants should understand the clinical importance of early melanoma detection, appreciate the challenges of early melanoma diagnosis and which patients are at highest risk, know the general principles of early melanoma detection, be familiar with current and emerging modalities that may facilitate early melanoma diagnosis and the detection of new and changing nevi, know the advantages and limitations of each modality, and be able to practice a combined approach to the patient with numerous or clinically atypical nevi.