Current controversies in early-stage melanoma: Questions on incidence, screening, and histologic regression

Preoperative bimodal imaging evaluation in finding histological correlations of in situ, superficial spreading and nodular melanoma

Background

The aim of this study is to correlate the diagnostic criteria described in dermoscopy, ultrasonography (US), and histology of the most common types of cutaneous melanoma (CM).

Methods

We conducted a prospective study including 40 CM cases, which were analyzed by dermoscopy using the Delta 30 dermatoscope and Vidix 4.0 videodermoscope, by ultrasound (US) using a high-resolution 20 MHz linear probe, along with histopathological analysis.

Results

The study involved 40 patients with histopathologically confirmed CM, comprising 10 nodular melanomas (NM), 21 superficial spreading melanomas (SSM), and nine in situ melanomas (MIS). US measurements of tumor thickness exhibited strong correlations with the histopathological Breslow index (BI), particularly in the NM and SSM groups. A notable correlation was observed between the presence of ulceration in histopathology and ultrasonography. Dermoscopic analysis revealed significant associations between specific features and CM types. For instance, the presence of an atypical network, irregular globules, irregular dots, prominent skin margins, angulated lines/polygons, dotted and short linear vessels, and negative network correlated with a median BI ≤ 0.5 mm. Conversely, the presence of blue-white veil, atypical vessels, blue-black color, and milky red color were associated with a median BI ≥ 2.3 mm. Furthermore, regression observed in histopathology correlated with regression identified in dermoscopy, we also found statistical correlations between the presence of vascularization at US with the high Clark level, and the presence of prominent skin markings at dermoscopy. The presence of histopathological regression was more frequently associated with tumors that had precise margins, absent vascularization and with those that did not have ulceration on US. The high mitotic rate was associated with tumors that presented imprecise margins, increased vascularization and US detectable ulceration.

Conclusion

Innovative CM diagnosis using non-invasive methods like dermoscopy and ultrasound may enhance accuracy and treatment guidance by assessing lesion characteristics.

Deciphering the immune reaction leading to spontaneous melanoma regression: initial role of MHCII+ CD163- macrophages

The human cutaneous metastatic melanoma is the deadliest skin cancer. Partial, or less frequently complete spontaneous regressions could be observed, mainly mediated by T cells. Nevertheless, the underlying mechanisms are not fully unraveled. We investigated the first events of the immune response related to cancer regression in Melanoma-bearing Libechov Minipigs (MeLiM), a unique swine model of cutaneous melanoma that regresses spontaneously. Using a multiparameter flow cytometry strategy and integrating new clinical and histological criteria of the regression, we show that T cells and B cells are present only in the late stages, arguing against their role in the initial destruction of malignant cells. NK cells infiltrate the tumors before T cells and therefore might be involved in the induction of the regression process. Myeloid cells represent the main immune population within the tumor microenvironment regardless of the regression stage. Among those, MHCII+ CD163- macrophages that differ phenotypically and functionally compared to other tumor-associated macrophages, increase in number together with the first signs of regression suggesting their crucial contribution to initiating the regression process. Our study supports the importance of macrophage reprogramming in humans to improve current immunotherapy for metastatic melanoma.

Acute regression of a melanocytic neoplasm

Immune-mediated regression of melanocytic neoplasms is predominantly lymphocytic, driven by CD8+ anti-tumoral T-cells and, rarely, natural killer cells. Histopathologic features of regression include effacement of the epidermis, replacement of tumor cells by a fibrotic stroma, varying degrees of chronic inflammation (usually lymphocytes) and melanophages, as well as vascular ectasia and angioplasia. The understanding of regression and the complex immune response in melanoma has led to the development of targeted immunotherapy in melanoma. Here, we report a case of near-complete regression of a melanocytic neoplasm associated with neutrophilic and eosinophilic inflammation, suggesting a non-traditional pathway of regression that has yet to be explored.

Not Your Mother's Melanoma: Causes and Effects of Early Melanoma Diagnosis

The year 2022 will herald approximately 100,000 new cases of cutaneous melanoma (CM), and over 7000 deaths from CM. Over the past 40 years, CM incidence has increased nearly six-fold; however, annual mortality has remained relatively constant. These trends encapsulate the phenomenon of overdiagnosis. Increased recognition of indolent lesions that appear histologically malignant may be leading to a melanoma epidemic. Enhanced melanoma awareness, screening efforts, physician uncertainty, medical-legal pressures, and diagnostic scrutiny using tools like immunohistochemical staining, mole mapping, dermoscopy, confocal microscopy, and molecular diagnostics contribute to increased CM diagnosis. As a result, current melanoma staging and treatment guidelines are being challenged. Existing standards fail to accurately identify histologically benign lesions that are lethal or, conversely, histologically malignant lesions that are innocuous. Healthcare systems and, more importantly, patients suffer from this diagnostic ambiguity that leads to the over-treatment of innocuous melanomas and under-treatment of aggressive melanomas. As dermatology continues to experience a shift towards earlier diagnosis of melanoma, management strategies must adapt. Herein, we review factors that may contribute to the increased incidence of melanoma, emphasize deficiencies in current staging systems, and provide insights into the future of melanoma management via precision medicine.

Melanoma of the Upper Limb and Shoulder: A Surveillance, Epidemiology, and End Results Analysis of Epidemiology and Survival 2000-2019

(1) Background: Melanoma is the most common life-threatening cancer among skin cancers. Almost all locations of the skin can be affected by melanoma, and the upper limbs are one of the most frequent locations. We aimed to study the epidemiology and survival outcomes of patients with melanoma localized in the upper extremities compared with other sites. (2) Methods: The National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) database is considered the most representative of the U.S. population; we extracted melanoma cases diagnosed between 2000 and 2019. Several characteristics, including demographical, pathological, and therapeutic, were recorded, and upper extremity melanomas and melanomas from other areas were compared. Overall survival was assessed, and the groups were compared. (3) Results: 69,436 patients had melanoma in the upper limbs and shoulders and 204,794 in other body parts. Overall, 35,267 patients with upper extremity melanoma were males, 34,169 were females, and the mean age was 60. For the rest of the body, there were 118,654 males and 86,140 females, with a mean age of 59. Surgery alone was the most commonly used treatment, while radiation therapy was the least used for all sites. Women appear to have better survival than men. Superficial spreading melanoma is the least lethal subtype, while nodular melanoma is the most dangerous. (4) Conclusion: Women under 50 are more at risk than men of the same age. The trend reverses after age 50 where men are at greater risk. In addition to gender and age, disease stage and major histologic subtypes influence survival.

Trends in Incidence of Conjunctival Melanoma in the US

This cohort study assesses the incidence of conjunctival melanoma, associations between demographic factors, and trends over time in the US.

To identify the association between dietary vitamin D intake and serum levels and risk or prognostic factors for melanoma-systematic review and meta-analysis

OBJECTIVE

To evaluate the association of serum vitamin D levels and dietary intake with melanoma risk and prognostic factors.

METHODS

Two independent investigators systematically searched PubMed, Embase and ISI Web of Knowledge (Thomson Scientific Technical Support, New York) databases for eligible studies published between January 1992 and September 2020 using the following combinations of search terms: (vitamin D, or 25-hydroxyvitamin D) AND (melanoma, malignant melanoma, cutaneous melanoma, or cutaneous malignant melanoma). Articles not written in English but with English titles and abstracts were also checked. We obtained the full text of all potentially eligible articles, and reference lists of all studies retrieved at the first stage were also checked to identify other eligible papers. Review articles not reporting original data were excluded, but their reference lists were inspected.

RESULTS

Six studies including 212 723 cases reported the association between dietary intake of 25(OH) D serum levels and melanoma risk. The total relative risk for the comparison between the highest and lowest quantiles of the distribution of vitamin D intake was 1.10 (95% CI 0.96 to 1.26) with I ²=56%. Another six studies including 12 297 cases evaluated the association between serum vitamin D levels and melanoma risk. The total relative risk for the comparison of serum vitamin D levels between the highest and lowest quantiles was 1.12 (95% CI 0.53 to 2.35) with I ²=91%. Four studies with 2105 cases investigated the association between serum 25(OH)D (nmol/L) and Breslow thickness, three of which found an inverse association between serum 25(OH)D (nmol/L) and melanoma thickness.

CONCLUSIONS

Vitamin D intake and serum 25(OH)D levels were not closely related with melanoma risk, but an inverse association between serum 25(OH)D levels with melanoma thickness was discovered. As the positive correlation between melanoma thickness and melanoma mortality has been recognised, hence it is concluded that a moderate dietary vitamin D supplement to avoid the serum 25(OH)D deficient might be beneficial to the long-term survival of patients with melanoma.

Clinical, Dermoscopic and Microscopic Features of a "Collision Tumour" Ultimately Confirmed as a Regressing Melanoma - Lessons Learnt from a Chance Diagnosis

Spontaneous regression of malignant melanoma was first reported over a century ago. Clinically, areas of blue or grey colouration in lesions may be indicative of regression. Dermoscopy is a very useful tool for diagnosing regression. An important criterion is the blue-white scar. About 10–35% of excised melanomas show features of regression histopathologically. We present a case of regressing melanoma, with clinical and dermoscopic features suggesting a collision tumour, diagnosed histopathologically. This case might improve our knowledge of the potential clinical manifestations, and the biology, of regressing melanoma.

Principles of Surgery in Head and Neck Cutaneous Melanoma

Surgical management of head and neck melanoma starts from the primary biopsy of the cutaneous site by a narrow excision with a 1 to 3 mm margins. The margin should include the whole breadth and sufficient depth of the lesion. The key is not to transect the lesion. With the advent of molecular testing, gene expression profiling, and immunotherapies, the surgical management of advanced melanoma has changed. Sentinel lymph node biopsy is an essential armamentarium for T2a and higher staging/greater than 1 mm thick and advance stage disease. Molecular pathogenesis and cancer immunology are recognized in the recent treatment protocols along with surgery in advanced stages of melanoma.

Chrysin Enhances Anti-tumor Immunity Response through IL-12-STAT4 Signal Pathway in B16F10 Melanoma Mouse Model

Chrysin (CHR) is a flavonoid with extensive pharmacological activity. The molecular formula of CHR is C₁₅ H₁₀ O₄ . CHR is reported to have antioxidative, anti-tumor and anti-viral functions. To evaluate its potential function as a vaccine adjuvant, we prepared a melanoma vaccine using a soluble protein extract of B16F10 melanoma cells as antigen and CHR as an adjuvant. The melanoma model was developed after two immunisations, and it was discovered that combining B16F10 soluble protein antigen-mixed CHR vaccine could inhibit tumor growth in the mouse model, and the overall survival rate was higher than that of the B16F10 antigen vaccine alone. In vivo and in vitro experiments were conducted to determine whether CHR functioned as an adjuvant by activating antigen-presenting cells (APCs). We discovered that CHR activated APCs both in vivo and in vitro and may enhance Th1 cell function by activating the IL12-STAT4 signal pathway, thereby enhancing the anti-tumor response of cytotoxic T lymphocytes (CTL) in vivo. Next, to verify the critical role of CD8⁺ T cells in suppressing melanoma development, we transplanted CD8⁺ T cells from immunised mice to B16F10 tumor-bearing mice and discovered that the survival rate of tumor-bearing mice was significantly prolonged. In summary, our experimental results indicate that CHR can be used as a potential adjuvant to enhance antigen immunogenicity, inhibit B16F10 tumor growth in mice and improve tumor immune response.

Antitumor activity of solamargine in mouse melanoma model: relevance to clinical safety

Melanoma is the most aggressive type of skin cancer, and thus it is important to develop new drugs for its treatment. The present study aimed to examine the antitumor effects of solamargine a major alkaloid heteroside present in Solanum lycocarpum fruit. In addition solamargine was incorporated into nanoparticles (NP) of yttrium vanadate functionalized with 3-chloropropyltrimethoxysilane (YVO₄:Eu³⁺:CPTES:SM) to determine antitumor activity. The anti-melanoma assessment was performed using a syngeneic mouse melanoma model B16F10 cell line. In addition, systemic toxicity, nephrotoxic, and genotoxic parameters were assessed. Solamargine, at doses of 5 or 10 mg/kg/day administered subcutaneously to male C57BL/6 mice for 5 days, decreased tumor size and frequency of mitoses in tumor tissue, indicative of a decrease in cell proliferation. Treatments with YVO₄:Eu³⁺:CPTES:SM significantly reduced the number of mitoses in tumor tissue, associated with no change in tumor size. There were no apparent signs of systemic toxicity, nephrotoxicity, and genotoxicity initiated by treatments either with solamargine alone or plant alkaloid incorporated into NP. The animals treated with YVO₄:Eu³⁺:CPTES:SM exhibited significant increase in spleen weight accompanied by no apparent histological changes in all tissues examined. In addition, animals treated with solamargine (10 mg/kg/day) and YVO₄:Eu³⁺:CPTES:SM demonstrated significant reduction in hepatic DNA damage which was induced by tumor growth. Therefore, data suggest that solamargine may be considered a promising candidate in cancer therapy with no apparent toxic effects.

TERT Promoter Revertant Mutation Inhibits Melanoma Growth through Intrinsic Apoptosis

Simple Summary

TERT -146 C>T frequently occurs in many cancer cells. Research targeting the telomerase reverse transcriptase (TERT) promoter contributes to a better understanding of cancer development and treatment. Many conventional cancer treatments aim to develop new drugs targeting TERT. Here, for TERT -146 we converted T to C. The proliferation, migration and invasion of melanoma cells in vitro, and the growth of the tumor in vivo were inhibited. Moreover, the downregulated protein expression of B-cell lymphoma 2 (Bcl-2) indicated that the TERT promoter revertant mutation abrogated the inhibitory effect of mutant TERT on apoptosis. These data elucidated the relationship between the TERT promoter revertant mutations and apoptosis for the first time, and also implied that TERT -146 may be a causal mutation of melanoma. This study provides a new insight into the TERT promoter revertant mutations and apoptosis. The TERT promoter provides preliminary validation of the potential tumor treatment.

Abstract

Human telomerase is a specialized DNA polymerase whose catalytic core includes both TERT and human telomerase RNA (hTR). Telomerase in humans, which is silent in most somatic cells, is activated to maintain the telomere length (TEL) in various types of cancer cells, including melanoma. In the vast majority of tumor cells, the TERT promoter is mutated to promote proliferation and inhibit apoptosis. Here, we exploited NG-ABEmax to revert TERT -146 T to -146 C in melanoma, and successfully obtained TERT promoter revertant mutant cells. These TERT revertant mutant cells exhibited significant growth inhibition both in vitro and in vivo. Moreover, A375^−146C/C cells exhibited telomere shortening and the downregulation of TERT at both the transcription and protein levels, and migration and invasion were inhibited. In addition, TERT promoter revertant mutation abrogated the inhibitory effect of mutant TERT on apoptosis via B-cell lymphoma 2 (Bcl-2), ultimately leading to cell death. Collectively, the results of our work demonstrate that reverting mutations in the TERT promoter is a potential therapeutic option for melanoma.

VISTA, PDL-L1, and BRAF-A Review of New and Old Markers in the Prognosis of Melanoma

Melanoma is currently known as one of the most aggressive malignant tumors. The prognostic factors and particularities of this neoplasm are a persistent hot topic in the medical field. This review has multiple purposes. First, we aim to summarize the known data regarding the histological and immunohistochemical appearance of this versatile tumor and to look further into the analysis of several widely used prognostic markers, such as B-Raf proto-oncogene, serine/threonine kinase BRAF. The second purpose is to analyze the data on the new prognostic markers, V-domain Immunoglobulin Suppressor of T cell Activation (VISTA) and Programmed death-ligand 1 (PD-L1). VISTA is a novel target that is considered to be highly important in determining the invasive potential and treatment response of a melanoma, and there are currently only a limited number of studies describing its role. PD-L1 is a marker with whose importance has been revealed in multiple types of malignancies, but its exact role regarding melanoma remains under investigation. In conclusion, the gathered data highlights the importance of correlations between these markers toward providing patients with a better outcome.

LINC01224 facilitates the proliferation and inhibits the radiosensitivity of melanoma cells through the miR-193a-5p/NR1D2 axis

Melanoma is a skin cancer characterized by early metastasis and high mortality. Radiotherapy is a common treatment for melanoma in patients. Long noncoding RNAs play pivotal roles in regulating the radiosensitivity of many tumors, including melanomas. In this study, the role of LINC01224 in the radiosensitivity of melanoma cells was explored. The expression of LINC01224 in melanoma was examined by reverse transcription-quantitative polymerase chain reaction, and the results showed that LINC01224 was upregulated in melanoma tissues and cells. The effects of LINC01224 on cell proliferation and apoptosis in melanoma were assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), colony formation, and flow cytometry assays. The effects of LINC01224 on the radiosensitivity of melanoma were analyzed by colony formation assay. The results implied that LINC01224 knockdown inhibited cell viability and proliferation but enhanced cell apoptosis and radiosensitivity. Luciferase reporter and RNA pull-down assays were performed to evaluate the relationships between LINC01224 and miR-193a-5p or miR-193a-5p and nuclear receptor subfamily 1 group D member 2 (NR1D2). We found that LINC01224 binds to miR-193a-5p, which directly targets NR1D2. In addition, we discovered that LINC01224 upregulated NR1D2 expression by sponging miR-193a-5p in melanoma cells. Overall, the data collected in this study suggest that LINC01224 exerts oncogenic effects in melanoma via the miR-193a-5p/NR1D2 axis.

Age and Cohort Trends of Malignant Melanoma in the United States

Simple Summary

The occurrence of melanoma in the United States is increasing over time. We examined trends in melanoma by birth year and age groups to determine if individuals born more recently experience higher rates of melanoma as they age. We examined these trends separately among men and women and by the location on the body that the melanoma occurred. Melanoma incidence has continued to increase across more recent birth years and varies by body site and sex. Melanoma incidence will likely continue to increase as younger individuals age. While these are mostly thin melanomas, treatment to prevent cancer progression is still costly, both economically and emotionally, for patients.

Abstract

The incidence of malignant melanoma in the United States is increasing, possibly due to changes in ultraviolet radiation (UVR) exposure due to lifestyle or increased awareness and diagnosis of melanoma. To determine if more recent birth cohorts experience higher rates of melanoma as they age, we examined age and birth cohort trends in the United States stratified by anatomic site and cancer type (in situ vs. malignant) of the melanoma diagnosed from 1975–2017. Poisson regression of cutaneous melanoma cases per population for 1975–2017 from the Surveillance, Epidemiology, and End Results (SEER) cancer registries was used to estimate age adjusted incidence for five-year birth cohorts restricted to Whites, ages 15–84. The rate of melanoma incidence across birth cohorts varies by anatomic site and sex. Melanomas at all anatomic sites continue to increase, except for head and neck melanomas in men. Much of the increase in malignant melanoma is driven by cases of thin (<1.5 mm) lesions. While increased skin exams may contribute to the increased incidence of in situ and thin melanoma observed across birth cohorts, the shifts in anatomic site of highest melanoma incidence across birth cohorts suggest changes in UVR exposure may also play a role.

Segmentation of dermoscopy images based on deformable 3D convolution and ResU-NeXt +

Melanoma is one of the most dangerous skin cancers. The current melanoma segmentation is mainly based on FCNs (fully connected networks) and U-Net. Nevertheless, these two kinds of neural networks are prone to parameter redundancy, and the gradient of neural networks disappears that occurs when the neural network backpropagates as the neural network gets deeper, which will reduce the Jaccard index of the skin lesion image segmentation model. To solve the above problems and improve the survival rate of melanoma patients, an improved skin lesion segmentation model based on deformable 3D convolution and ResU-NeXt++ (D3DC- ResU-NeXt++) is proposed in this paper. The new modules in D3DC-ResU-NeXt++ can replace ordinary modules in the existing 2D convolutional neural networks (CNNs) that can be trained efficiently through standard backpropagation with high segmentation accuracy. In particular, we introduce a new data preprocessing method with dilation, crop operation, resizing, and hair removal (DCRH), which improves the Jaccard index of skin lesion image segmentation. Because rectified Adam (RAdam) does not easily fall into a local optimal solution and can converge quickly in segmentation model training, we also introduce RAdam as the training optimizer. The experiments show that our model has excellent performance on the segmentation of the ISIC2018 Task I dataset, and the Jaccard index achieves 86.84%. The proposed method improves the Jaccard index of segmentation of skin lesion images and can also assist dermatological doctors in determining and diagnosing the types of skin lesions and the boundary between lesions and normal skin, so as to improve the survival rate of skin cancer patients. Overview of the proposed model. An improved skin lesion segmentation model based on deformable 3D convolution and ResU-NeXt++ (D3DC- ResU-NeXt++) is proposed in this paper. D3DC-ResU-NeXt++ has strong spatial geometry processing capabilities, it is used to segment the skin lesion sample image; DCRH and transfer learning are used to preprocess the data set and D3DC-ResU-NeXt++ respectively, which can highlight the difference between the lesion area and the normal skin, and enhance the segmentation efficiency and robustness of the neural network; RAdam is used to speed up the convergence speed of neural network and improve the efficiency of segmentation.

A Retrospective, Observational Analysis of Tumor Infiltrating Lymphocytes and Tumor Regression in Melanoma

BACKGROUND

Tumor infiltrating lymphocytes (TILs) and regression are thought to be distinct markers of the immune response to melanoma.

OBJECTIVE

This study sought to analyze the relationship of TIL grade and presence of regression to each other and to other prognostic histopathologic and clinical values in melanoma.

MATERIALS AND METHODS

A retrospective analysis was conducted using patients diagnosed with melanoma between 2013 and 2019 whose complete histopathologic reports were available.

RESULTS

Regression was seen in 48.9%, 30.1% and 37.9% of patients with brisk, non-brisk, and absent TILs respectively (P=0.019). Melanoma tumors with brisk TILs were found to have a lower Breslow thickness than those with non-brisk or absent (P= 0.001). Tumors with regression were also found to have lower Breslow thickness (P<0.001). Neither TIL grade nor regression were protective of nodal metastasis or associated with improved survival.

CONCLUSION

Brisk TILs have a positive association with thinner tumors and the presence of tumor regression relative to non-brisk or absent TILs. This may suggest a more robust immune response in tumors with brisk TILs. Further exploration of the interplay between TIL grade, lymphocyte cell subtype and lymphocyte density may help explain this finding.

Skin melanoma deaths within 1 or 3 years from diagnosis in Europe

The steep increase in incidence of cutaneous malignant melanoma in white populations mainly applies to thin lesions with good survival suggesting overdiagnosis. Based on population-based cancer registries (CRs), we have investigated changes in aggressive melanoma, selecting only cases who died within 1 or 3 years after diagnosis in 11 European countries between 1995 and 2012. Trends in fatal cases were analysed by period of diagnosis, sex, tumour thickness, histologic subtype of the lesion, tumour site and CR with a multivariate generalised linear mixed effects model, where geographical area was considered as a random effect. We collected data on 123 360 invasive melanomas, with 5133 fatal cases at 1 year (4%) and 12 330 (10%) at 3 years. The number of fatal cases showed a 16% decrease at 1 year and 8% at 3 years between the first (1995-2000) and the last (2007-2012) period. The highest proportion of fatal cases was seen for men, older age (≥65 years), thick lesions (>1 mm), nodular melanoma, melanoma on the trunk and for poorly documented cases, lacking information about thickness and histologic subtype. The mixed-effects model showed a remarkable variability among European countries. The majority of registries showed a decreasing trend in fatal cases, but a few registries showed an opposite pattern. Trends in fatal melanoma cases, highlighting real changes in risk not related to overdiagnosis, showed a decrease in most European countries, with a few exceptions. Stronger efforts for early detection could lead to a more efficient treatment of melanoma in general.

Immunotherapy in Acral and Mucosal Melanoma: Current Status and Future Directions

Acral and mucosal melanomas are extremely rare in Caucasians; however, they are the predominant melanoma subtypes in Asians and other non-Caucasian populations. Acral and mucosal melanomas share many clinicopathological features, including aggressive phenotypes, similar genetic landscapes, and grim prognoses. In spite of advances in melanoma management, patients with acral and mucosal melanomas show limited benefit from current therapies. The rarity of these subtypes of melanoma is a significant factor contributing to the poor understanding of these pathological subtypes and the lack of effective interventions. Furthermore, the mechanisms contributing to disparities between different types of melanoma remain largely unclear. Herein, we comprehensively review current knowledge on the clinicopathological characteristics and mutational landscapes of acral and mucosal melanomas, as well as providing an overview of current therapies for patients with these aggressive melanoma subtypes, focusing on available immunotherapeutic interventions. We also discuss pathological differences between different melanoma subtypes and summarize current knowledge on melanoma disparities between Asians and Caucasians. Finally, we discuss emerging immunotherapeutic strategies for the treatment of acral and mucosal melanomas, focusing on combination therapies with immune checkpoint inhibitors. Unraveling the unique features of acral and mucosal melanomas is key for their early diagnosis and for the development of effective therapies.

Molecular Biomarkers for Melanoma Screening, Diagnosis and Prognosis: Current State and Future Prospects

Despite significant progress in the development of treatment options, melanoma remains a leading cause of death due to skin cancer. Advances in our understanding of the genetic, transcriptomic, and morphologic spectrum of benign and malignant melanocytic neoplasia have enabled the field to propose biomarkers with potential diagnostic, prognostic, and predictive value. While these proposed biomarkers have the potential to improve clinical decision making at multiple critical intervention points, most remain unvalidated. Clinical validation of even the most commonly assessed biomarkers will require substantial resources, including limited clinical specimens. It is therefore important to consider the properties that constitute a relevant and clinically-useful biomarker-based test prior to engaging in large validation studies. In this review article we adapt an established framework for determining minimally-useful biomarker test characteristics, and apply this framework to a discussion of currently used and proposed biomarkers designed to aid melanoma detection, staging, prognosis, and choice of treatment.

Estimating the potential impact of interventions to reduce over-calling and under-calling of melanoma

BACKGROUND

Pathologists sometimes disagree over the histopathologic diagnosis of melanoma. 'Over-calling' and 'under-calling' of melanoma may harm individuals and healthcare systems.

OBJECTIVES

To estimate the extent of 'over-calling' and 'under-calling' of melanoma for a population undergoing one excision per person and to model the impact of potential solutions.

METHODS

In this epidemiological modelling study, we undertook simulations using published data on the prevalence and diagnostic accuracy of melanocytic histopathology in the U.S.

POPULATION

We simulated results for 10 000 patients each undergoing excision of one melanocytic lesion, interpreted by one community pathologist. We repeated the simulation using a hypothetical intervention that improves diagnostic agreement between community pathologist and a specialist dermatopathologist. We then evaluated four scenarios for how melanocytic lesions judged to be neither clearly benign (post-test probability of melanoma < 5%), nor clearly malignant (post-test probability of melanoma > 90%) might be handled, before sending for expert dermatopathologist review to decide the final diagnosis. These were (1) no intervention before expert review, (2) formal second community pathologist review, (3) intervention to increase diagnostic agreement and (4) both the intervention and formal second community pathologist review. The main outcomes were the probability of 'over-calling' and 'under-calling' melanoma, and number of lesions requiring expert referral for each scenario.

RESULTS

For 10 000 individuals undergoing excision of one melanocytic lesion, interpreted by a community pathologist, a hypothetical intervention to improve histopathology agreement reduced the number of benign lesions 'over-called' as melanoma from 308 to 164 and the number of melanomas 'under-called' from 289 to 240. If all uncertain diagnoses were sent for expert review, the number of referrals would decrease from 1500 to 737 cases if formal second community pathologist review was used, and to 701 cases if the hypothetical intervention was additionally used.

CONCLUSIONS

Interventions to improve histopathology agreement may reduce melanoma 'over-calling' and 'under-calling'.

Cutaneous malignant melanoma mortality in Andalusia from 1979 to 2018. Toward new perspectives?

Malignant melanoma accounts for 80% of deaths due to skin cancer. Its incidence is globally increasing. However, melanoma mortality seems to be decreasing. The aim of this study was to analyze mortality rates due to melanoma in Andalusia between 1979 and 2018. Deaths due to melanoma and mid-year population in Andalusia were collected from the National Institute of Statistics. Age-adjusted mortality rates were calculated for overall population and for each sex and age group. Regression models were used to calculate significant points of change. Sex ratio and the independent effects of age, period, and cohort were also analyzed. Age-adjusted mortality due to melanoma rose from 0.61 to 1.94 deaths per 100.000 from 1979 to 2018 for the overall population. A significant change of trends was detected around 1994 when, after a steady rise from 1979, mortality rates stabilized up to the end of the period studied. The cited increase was more pronounced in >64 year males. From the end of the 2000s, there was a decrease in mortality rates to date in all population groups, producing a period effect. A stabilization in melanoma mortality rates was observed in Andalusia from 1994 with a decrease in some groups at the beginning of the 21st century. Trends observed in Andalusia do not differ substantially from those in Spain. The development of new therapies and an earlier diagnosis may have an influence in those changes. Studies that compare differences between Spanish regions are needed to define better prevention strategies.

Prognostic significance of regression and mitotic rate in head and neck cutaneous melanoma

Importance

While regression is a commonly reported microscopic feature of melanoma, its prognostic significance is unclear.

Objective

To examine the impact of regression on sentinel node status and the likelihood of recurrence in primary cutaneous melanoma of the head and neck.

Design

Retrospective analysis of 191 adults who underwent surgical management for primary cutaneous melanoma of the head and neck between May 2002 and March 2019.

Setting

Tertiary academic center.

Participants

Patients appropriate for the study were identified by the Academic Health Center Information Exchange using a list of current procedural terminology codes. One hundred and ninety‐one cases of invasive melanoma of the head and neck were included from 830 patients identified. Clinical features assessed for each patient included age, sex, location of primary lesion, date of diagnosis, and current disease status (alive with or without disease). Histologic features assessed were histological melanoma subtype (nodular vs non‐nodular), Breslow thickness, Clark level, presence/absence of ulceration, mitotic rate per square millimeter, and regression. If applicable, sentinel lymph node biopsy (SLNB) status, date of recurrence, interval treatments, and date of death related to melanoma were recorded. Exclusion criteria included melanoma outside the anatomic parameters of head and neck, ocular or choroidal melanoma, mucosal melanoma, metastatic melanoma to the head or neck with no known primary tumor, melanoma of the head or neck with no surgical intervention, and non‐melanoma skin cancers of the head and neck.

Intervention/Exposure

Surgery for cutaneous melanoma of the head and neck.

Main Outcome(s) and Measure(s)

The association between presence of regression and Breslow thickness, sentinel node status, and recurrence.

Results

Of the 191 patients identified, 30.9% were female and 69.1% were male with a mean age at diagnosis of 62.6 (range 20‐97) years. Mean Breslow thickness was 1.2 mm in those with regression and 2.0 mm in those without regression. In patients with regression, 17.6% had a positive sentinel node, and 13.0% experienced a recurrence. In patients without regression, 26.5% had a positive sentinel node, and 31.4% experienced a recurrence. When adjusted for other factors above, regression was not associated with positive sentinel node (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.13‐2.00) or recurrence (OR = 0.33, CI = 0.07‐1.01). Mitotic rate >2 was associated with recurrence (OR = 2.71, CI = 1.11‐6.75, P = .03).

Conclusions and Relevance

Patients with presence of regression had thinner melanomas and trended toward decreased rates of sentinel node positivity and recurrence, suggesting regression may not be a negative prognostic indicator in patients with cutaneous melanoma of the head and neck.

Analyzing Controversies in Management and Surveillance of Early-Stage Melanoma

The incidence of cutaneous melanoma continues to rise dramatically worldwide, presenting a significant burden to the healthcare system. Despite this, there is still controversy in the guidelines regarding follow-up surveillance for patients with thin melanoma. Since there are no randomized clinical trials to support evidence-based guidelines for follow-up surveillance, dermatologic and oncologic organizations have developed their own recommendations based on expert opinion. However, these recommendations differ widely and are often vague, resulting in considerable variability in the management of early-stage melanoma among clinicians. The benefits of frequent follow-up visits are early detection of recurrent lesions, lower cost of early-stage melanoma compared to that of late-stage melanoma, decreased need for sentinel lymph node biopsy and adjuvant therapies, and the opportunity to educate patients on self-examination and sun protection. However, the high cost of screening and potential increased rates of biopsy, as well as over-imaging and overtreating, pose serious concerns about this approach. While more rigorous research is needed to resolve this controversy, currently clinicians should follow a relatively universal recommendation to tailor the follow-up regimen based on the patient's relative risk of recurrence and comfort.

Reporting regression in primary cutaneous melanoma. Part 2: prognosis, evaluation and management

The effect of histological regression on patient prognosis for primary cutaneous melanoma is controversial. Some authors hypothesize that regression indicates a robust systemic immune response and may decrease risk of metastasis. Others argue that histological regression calls into question a T0 diagnosis because there may have been an invasive component of the melanoma that is no longer visible but is still active. The literature to date does not suggest that histological regression is associated with increased risk of positive sentinel lymph node status, metastasis or increased risk of mortality. Thus, the presence of histological regression should not change patient staging, evaluation or management. The criteria used for reporting regression have varied dramatically across studies, and standardized reporting is needed to foster evidence-based practices in the future.

Overdiagnosis of melanoma - causes, consequences and solutions

Malignant melanoma is the skin tumor that causes most deaths in Germany. At an early stage, melanoma is well treatable, so early detection is essential. However, the skin cancer screening program in Germany has been criticized because although melanomas have been diagnosed more frequently since introduction of the program, the mortality from malignant melanoma has not decreased. This indicates that the observed increase in melanoma diagnoses be due to overdiagnosis, i.e. to the detection of lesions that would never have created serious health problems for the patients. One of the reasons is the challenging distinction between some benign and malignant lesions. In addition, there may be lesions that are biologically equivocal, and other lesions that are classified as malignant according to current criteria, but that grow so slowly that they would never have posed a threat to patient's life. So far, these "indolent" melanomas cannot be identified reliably due to a lack of biomarkers. Moreover, the likelihood that an in-situ melanoma will progress to an invasive tumor still cannot be determined with any certainty. When benign lesions are diagnosed as melanoma, the consequences are unnecessary psychological and physical stress for the affected patients and incurred therapy costs. Vice versa, underdiagnoses in the sense of overlooked melanomas can adversely affect patients' prognoses and may necessitate more intense therapies. Novel diagnostic options could reduce the number of over- and underdiagnoses and contribute to more objective diagnoses in borderline cases. One strategy that has yielded promising results in pilot studies is the use of artificial intelligence-based diagnostic tools. However, these applications still await translation into clinical and pathological routine.

Diagnostics of Melanocytic Skin Tumours by a Combination of Ultrasonic, Dermatoscopic and Spectrophotometric Image Parameters

Dermatoscopy, high-frequency ultrasonography (HFUS) and spectrophotometry are promising quantitative imaging techniques for the investigation and diagnostics of cutaneous melanocytic tumors. In this paper, we propose the hybrid technique and automatic prognostic models by combining the quantitative image parameters of ultrasonic B-scan images, dermatoscopic and spectrophotometric images (melanin, blood and collagen) to increase accuracy in the diagnostics of cutaneous melanoma. The extracted sets of various quantitative parameters and features of dermatoscopic, ultrasonic and spectrometric images were used to develop the four different classification models: logistic regression (LR), linear discriminant analysis (LDA), support vector machine (SVM) and Naive Bayes. The results were compared to the combination of only two techniques out of three. The reliable differentiation between melanocytic naevus and melanoma were achieved by the proposed technique. The accuracy of more than 90% was estimated in the case of LR, LDA and SVM by the proposed method.

Germline mutations predisposing to melanoma

Nearly 15% of melanomas occur in patients with a family history and a subset of these patients have a germline mutation in a melanoma predisposing gene. CDKN2A mutations are responsible for the majority of hereditary melanoma, but many other susceptibility genes have been discovered in recent years, including CDK4, TERT, ACD, TERF2IP, POT1, MITF, MC1R, and BAP1. Additionally, melanoma risk is increased in mixed cancer syndromes caused by mutations in PTEN, BRCA2, BRCA1, RB1, and TP53. While early onset, multiple tumors, and family cancer history remain the most valuable clinical clues for hereditary melanoma, characteristic epithelioid cytology of melanocytic tumors may suggest an underlying BAP1 mutation. Herein, we review the clinical and histopathologic characteristics of melanocytic tumors associated with these germline mutations and discuss the role of genetic counseling.

Model Combining Tumor Molecular and Clinicopathologic Risk Factors Predicts Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma

PURPOSE

More than 80% of patients who undergo sentinel lymph node (SLN) biopsy have no nodal metastasis. Here we describe a model that combines clinicopathologic and molecular variables to identify patients with thin and intermediate thickness melanomas who may forgo the SLN biopsy procedure due to their low risk of nodal metastasis.

PATIENTS AND METHODS

Genes with functional roles in melanoma metastasis were discovered by analysis of next generation sequencing data and case control studies. We then used PCR to quantify gene expression in diagnostic biopsy tissue across a prospectively designed archival cohort of 754 consecutive thin and intermediate thickness primary cutaneous melanomas. Outcome of interest was SLN biopsy metastasis within 90 days of melanoma diagnosis. A penalized maximum likelihood estimation algorithm was used to train logistic regression models in a repeated cross validation scheme to predict the presence of SLN metastasis from molecular, clinical and histologic variables.

RESULTS

Expression of genes with roles in epithelial-to-mesenchymal transition (glia derived nexin, growth differentiation factor 15, integrin β3, interleukin 8, lysyl oxidase homolog 4, TGFβ receptor type 1 and tissue-type plasminogen activator) and melanosome function (melanoma antigen recognized by T cells 1) were associated with SLN metastasis. The predictive ability of a model that only considered clinicopathologic or gene expression variables was outperformed by a model which included molecular variables in combination with the clinicopathologic predictors Breslow thickness and patient age; AUC, 0.82; 95% CI, 0.78-0.86; SLN biopsy reduction rate of 42% at a negative predictive value of 96%.

CONCLUSION

A combined model including clinicopathologic and gene expression variables improved the identification of melanoma patients who may forgo the SLN biopsy procedure due to their low risk of nodal metastasis.

Improved melanoma outcomes and survival in patients monitored by total body photography: A natural experiment

Total body photography (TBP) facilitates early melanoma detection, but long-term outcomes have not been well studied. Our objectives were to examine melanoma diagnoses, role of TBP-associated follow-up visits, and survival in patients monitored by TBP. A total of 1955 patients meeting inclusion criteria received TBP from 2004-2013 at a single academic center. We compared the melanoma diagnoses and overall survival of 1253 patients with any follow-up visits (median, three visits; range, 1-18) and 702 patients with no follow-up visits. Use of TBP photographs influenced decision to biopsy 66 of 121 (54.5%) melanomas diagnosed after TBP. Lower invasive melanoma Breslow depth was significantly associated with having one or more follow-up visit (median, 0.83 vs 0.33 mm; P = .002) and photographic review (median, 0.31 vs 0.48 mm; P = 0.02). In multivariable analyses, greater overall survival was significantly associated with having one or more follow-up visit after TBP (hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.14-0.91; P < 0.032) and having more than 100 nevi (HR, 0.37; 95% CI, 0.22-0.64; P = 0.004). Worse overall survival was significantly associated with increasing age (HR per year, 1.06; 95% CI, 1.04-1.08; P < 0.001) and male sex (HR, 2.65; 95% CI, 1.48-4.73; P = 0.001). Thus, monitoring by TBP was associated with subsequent melanoma diagnoses of lower stage and depth and greater overall survival.