[Screening for cutaneous melanoma: little impact, major challenges]

Routine screening for melanoma has never been shown to be effective. Here, we revisit this debate and the preconceived notion that the increased detection of early-stage melanoma should necessarily be followed within the same population by a reduction in the incidence of advanced stages, which is not supported by any evidence. The issue of overdiagnosis, which has been debated for several decades, is discussed in the light of screening practices. We illustrate with two of its common motives, why this practice is ineffective. Finally, we suggest that the risk of overdiagnosis has probably reached its climax over the last two decades, as the increasing sensitivity of skin-imaging tools has not been followed by a refinement of histopathologic diagnostic criteria.

The human antigen R as an actionable super-hub within the network of cancer cell persistency and plasticity

In this perspective article, a clinically inspired phenotype-driven experimental approach is put forward to address the challenge of the adaptive response of solid cancers to small-molecule targeted therapies. A list of conditions is derived, including an experimental quantitative assessment of cell plasticity and an information theory-based detection of in vivo dependencies, for the discovery of post-transcriptional druggable mechanisms capable of preventing at multiple levels the emergence of plastic dedifferentiated slow-proliferating cells. The approach is illustrated by the author's own work in the example case of the adaptive response of BRAFV600-melanoma to BRAF inhibition. A bench-to-bedside and back to bench effort leads to a therapeutic strategy in which the inhibition of the baseline activity of the interferon-γ-activated inhibitor of translation (GAIT) complex, incriminated in the expression insufficiency of the RNA-binding protein HuR in a minority of cells, results in the suppression of the plastic, intermittently slow-proliferating cells involved in the adaptive response. A similar approach is recommended for the validation of other classes of mechanisms that we seek to modulate to overcome this complex challenge of modern cancer therapy.

Swiss Recommendations for Cutaneous Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer in Switzerland and worldwide. Most BCCs can be treated in a curative setting. However, patients can develop locally destructive and, rarely, metastatic tumors that require a different treatment approach. The clinical subtype of individual lesions provides prognostic information and influences management decisions. Surgical excision, topical therapies, and radiotherapy are highly effective in the majority of subtypes as well as in low- and high-risk diseases. For patients with low-risk diseases and superficial tumors not amenable to surgery, several nonsurgical alternatives are available. Systemic therapy is indicated for high-risk BCCs, which are not amenable to either surgery or radiotherapy. Hedgehog pathway inhibitors (HHI) are currently approved. Other therapeutic options such as immune checkpoint inhibitors show promising results in clinical trials. This first version of Swiss recommendations for diagnosis and management of BCC was prepared through extensive literature review and an advisory board consensus of expert dermatologists and oncologists in Switzerland. The present guidelines recommend therapies based on a multidisciplinary team approach and rate of recurrence for individual lesions. Based on the risk of recurrence, two distinct groups have been identified: low-risk (easy-to-treat) and high-risk (difficult-to-treat) tumors. Based on these classifications, evidence-based recommendations of available therapies are presented herein.

Rintala Flap and Posterior Perichondrial Cutaneous Graft: A Combined Approach for Nasal Tip Reconstruction

Nasal tip reconstruction requires a meticulous approach due to the complexity of the nasal anatomy and its aesthetic importance. Many procedures have been described to restore this aesthetic unit, including the paramedian forehead flap, which is one of the workhorse flaps. However, despite excellent final outcomes, this procedure may be refused by patients, due to its temporary conspicuous appearance possibly associated with serious psychological implications, and the need of multiple interventions. We aimed to present an approach combining the Rintala flap and the posterior perichondrial cutaneous graft as a valuable alternative to treat large nasal tip defects.

[BRAF inhibitors-induced paradoxical reactions and oncogenesis]

Paradoxical oncogenesis and benign paradoxical proliferations occur in off-target rapidly regenerating labile tissues of patients treated for malignancies with small-molecule inhibitors of cell-signaling such as kinase inhibitors. These paradoxical proliferations, particularly well listed in patients treated with selective BRAF inhibitors carrying BRAF-mutated solid malignancies, have had their incidence reduced upon the advent of BRAF/MEK double blockade therapies. Mechanistically, the underlying molecular events involved in paradoxical proliferations in off-target tissues could prove to be as complex as those involved in the adaptive resistance of malignant cells to targeted therapies.

A mutual information-based in vivo monitoring of adaptive response to targeted therapies in melanoma

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In vivo dependencies should be quantified in adaptive resistance mechanistic studies

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Mutual information (MI) quantifies any type rather than just linear dependencies

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MI outperforms classic expression correlation coefficients

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Adaptive response to small-molecules inhibitors can be monitored in vivo using MI

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Strategies that prevent adaptive resistance can be monitored in vivo using MI

The mechanisms of adaptive resistance to genetic-based targeted therapies of solid malignancies have been the subject of intense research. These studies hold great promise for finding co-targetable hub/pathways which in turn would control the downstream non-genetic mechanisms of adaptive resistance. Many such mechanisms have been described in the paradigmatic BRAF-mutated melanoma model of adaptive response to BRAF inhibition. Currently, a major challenge for these mechanistic studies is to confirm in vivo, at the single-cell proteomic level, the existence of dependencies between the co-targeted hub/pathways and their downstream effectors. Moreover, the drug-induced in vivo modulation of these dependencies needs to be demonstrated. Here, we implement such single-cell-based in vivo expression dependency quantification using immunohistochemistry (IHC)-based analyses of sequential biopsies in two xenograft models. These mimic phase 2 and 3 trials in our own therapeutic strategy to prevent the adaptive response to BRAF inhibition. In this mechanistic model, the dependencies between the targeted Li₂CO₃-inducible hub HuR and the resistance effectors are more likely time-shifted and transient since the minority of HuR^Low cells, which act as a reservoir of adaptive plasticity, switch to a HuR^High state as they paradoxically proliferate under BRAF inhibition. Nevertheless, we show that a copula/kernel density estimator (KDE)-based quantification of mutual information (MI) efficiently captures, at the individual level, the dependencies between HuR and two relevant resistance markers pERK and EGFR, and outperforms classic expression correlation coefficients. Ultimately, the validation of MI as a predictive IHC-based metric of response to our therapeutic strategy will be carried in clinical trials.

Anti-PD-1-Induced Hidradenitis Suppurativa

Mucocutaneous adverse events are commonly observed under immune checkpoint inhibitors (ICIs) therapy. Here, we report the case of a 43-year-old male patient with a stage IIIC melanoma disease who developed hidradenitis suppurativa (HS) three months after the beginning of an anti-PD-1 (nivolumab) adjuvant therapy. The patient had no comorbidities other than obesity and severe acne during adolescence. After an unsuccessful course of lymecycline while he was still treated with nivolumab, he gradually improved under zinc gluconate therapy and, more importantly, after nivolumab cessation. HS is a recurrent follicular inflammatory disease in the apocrine gland-bearing areas of the body often associated with obesity, metabolic syndrome, tobacco smoking, inflammatory bowel diseases, psoriasis, and arthritis. In our patient, the latency period between drug initiation and onset of HS symptoms and the improvement after immunotherapy discontinuation, argued strongly in favor of an anti-PD-1-induced HS. Anti-PD-1 therapies often trigger T cells-mediated adverse events that mimic Th17-mediated inflammatory and neutrophilic diseases. We suggest that HS, as other pustular skin reactions and ICIs-induced neutrophilic colitis, can be part of the anti-PD-1 mucocutaneous adverse event spectrum.

Skin cancer screening in Switzerland: Cross-sectional trends (1997-2012) in socioeconomic inequalities

INTRODUCTION

Skin cancer is one of the most common malignancies. Despite controversy over its efficacy, skin cancer screening has become widespread although socioeconomic screening inequalities have been documented. Switzerland has the highest rate of melanoma in Europe but Swiss trends in skin cancer screening and social disparities have not been investigated. This study aims to evaluate trends in skin cancer screening and its association with socioeconomic indicators in Switzerland between 1997 and 2012.

METHOD

We used data from four waves (from 1997 to 2012) of the population-based Swiss Health Interview Survey. Multivariable Poisson regressions with robust variance were used to estimate weighted prevalence ratio (PR) and 95% Confidence Intervals (CI) adjusting for demographics, health status and use of healthcare.

RESULTS

This study included 60,764 participants with a mean age of 49.1 years (standard deviation (SD) 17.2) and 53.6% of women. Between 1997 and 2012, the weighted prevalence of ever life-time skin examination and skin examination in the current year increased by 38.2% and 35.3% respectively (p-value <0.001). Participants with a lower education level, lower income and living in non-metropolitan areas were less often screened than their counterparts. Educational differences in ever life-time skin examination increased over time (p-value for trend = 0.036).

CONCLUSION

While skin cancer screening prevalence in Switzerland increased from 1997 to 2012, most social inequalities persisted over time and educational inequalities increased. Dermatologists should be alerted that populations with lower education should be given special attention.

[Recent advances in the adjuvant treatment of high-risk melanoma]

Despite tremendous therapeutic innovations during the last decade, the prognosis of metastatic melanoma remains uncertain. Adjuvant therapy following resection of high-risk melanoma is currently under intense investigation. Both small-molecules targeted therapy and immune checkpoint inhibitor therapy, initially developed for metastatic disease, have proven to be efficient in the adjuvant setting in phase 3 trials. The results of this research are already considered as practice-changing. In this article we summarize this ongoing clinical research and its consequences for the practical management of high-risk melanoma patients.

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.

Hu antigen R (HuR) heterogeneous expression quantification as a prognostic marker of melanoma

BACKGROUND

Prognostic markers for melanoma, particularly for stage II disease, are needed for the risk-benefit evaluation of future adjuvant therapies. The mainly nuclear RNA-binding protein human antigen R (HuR) regulates the protein expression of thousands of mRNAs, its own heterogeneous expression could therefore reflect tumor heterogeneity and plasticity. Here, we evaluate its quantification in primary melanoma as a marker of metastatic outcome.

METHODS

We conducted an immunohistochemistry-based automated quantification of HuR nuclear expression heterogeneity in primary melanomas, most with Breslow thickness ≥ 1 mm and calculated the dimensionless fourth moment, that is, the kurtosis of HuR (HuR K) expression distribution. Twelve tumors from patients with no metastatic disease were compared to a similar number of tumors from patients who had metastatic disease at 2 years follow up.

RESULTS

HuR K value appeared significantly higher in the non-metastatic group comparatively to the metastatic group (P = 2.84 × 10^-3 , 1-tailed Wilcoxon rank-sum test). Moreover, compared to the Breslow thickness, HuR K value appeared as a more robust marker of metastatic outcome (respective areas under receiver operating characteristic curves 0.84 and 0.87).

CONCLUSION

Our data need confirmation on a large cohort, however strongly suggest that HuR expression heterogeneity quantification using kurtosis, could be used as a prognostic marker in melanoma.

Evaluation of the National Swiss Skin Cancer Screening Campaign 2013: Do We Do the Right Thing

BACKGROUND

Skin cancer prevention and screening programs are performed in many countries. Their benefit is discussed controversially.

OBJECTIVE

Our aim is to evaluate the Skin Cancer Screening Program 2013 in Switzerland by following up screenees upon interventions.

METHODS

Quality was assessed by personal follow-up via phone/e-mail of every patient that had been screened during this campaign and histological follow-up of all participants with suspicious skin lesions.

RESULTS

Of the 1,087 screenees requiring interventions, 263 agreed to participate in the follow-up. We were able to obtain 66 histology reports. During this campaign 33 malignant lesions (8 melanomas) were removed.

CONCLUSION

The overall melanoma detection rate in our free Skin Cancer Screening Program is comparable to those in European public activities. The costs of free screening programs compare favorably with the prevented potential therapeutic costs of late-stage melanoma. The low response rate of screenees agreeing to be followed up limits conclusions of this study.

Overexpression of the human antigen R suppresses the immediate paradoxical proliferation of melanoma cell subpopulations in response to suboptimal BRAF inhibition

Tumor plasticity and the heterogeneous response of melanoma cells to targeted therapies are major limits for the long‐term efficacy of this line of therapy. Targeting tumor plasticity is theoretically possible through the modulation of the expression of RNA‐binding proteins which can affect many different compensatory mechanisms of the adaptive response of malignant cells to targeted therapies. Human antigen R (HuR) is a modulator of gene expression and a transacting factor in the mRNA‐processing machinery used in the cell stress response, and is a potential target for reducing tumor plasticity. In this experiment, we exploit the inherent heterogeneous response of the A375 melanoma line to suboptimal BRAF inhibition as a model of immediate adaptive response. We first observe that HuR overexpression can prevent the heterogeneous response and thus the immediate paradoxical proliferation induced by low‐doses vemurafenib treatment. We then use single‐cell mass cytometry to characterize subpopulations, including those that paradoxically proliferate, based on their proliferation rate and the expression patterns of markers involved in the reversible adaptive resistance to BRAF inhibition and/or recognized as HuR targets involved in cell cycle regulation. Under suboptimal BRAF inhibition, HuR overexpression affects these subpopulations and their expression pattern with contrasting responses depending on their proliferation rate: faster‐proliferating vemurafenib‐sensitive or ‐resistant subpopulations showed higher death tendency and reduced size, and slower‐proliferating subpopulations showed an attenuated resistant expression response and their paradoxical proliferation was inhibited. These observations pave the way to new therapeutic strategies for preventing the heterogeneous response of tumors to targeted therapies.

In vivo reflectance confocal microscopy: a useful non-invasive tool to assess the response to isolated limb perfusion for superficial pigmented melanoma in-transit metastatic disease. Report of a case

Complete response can be difficult to assess after isolated limb perfusion (ILP) for metastatic in-transit melanoma, especially when numerous and unresectable post-necrotic persisting pigmented lesions occur. These residual lesions are mainly seen in the more superficial and pigmented types of metastatic disease and correspond to the residual melanophage granuloma that persists after tumor tissues undergo complete necrosis. Reflectance confocal microscopy (RCM) is a non-invasive technique that allows the exploration of the superficial dermis. Here, we present the case of a patient in whom numerous post-ILP limb residual pigmented lesions were explored using combined RCM and histological examination of sample lesions and could be characterized as non-active. This approach allowed us to avoid additional excisions.

Psammomatous Melanotic Schwannoma: A Challenging Histological Diagnosis

Psammomatous melanotic schwannoma (PMS) is a rare pigmented tumor that can be part of the Carney complex. Here, we describe the case of a 35-year-old female patient presenting an isolated subcutaneous PMS. Histopathological analysis could not formally exclude the malignant nature of the tumor. The challenging histological diagnosis and consequently the management of the patient are described.

HIV-1 infection of primary effusion lymphoma cell line triggers Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation

Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus etiologically linked to primary effusion lymphoma (PEL), to a subset of multicentric Castleman's disease and to Kaposi's sarcoma (KS), the most common neoplasm associated with AIDS. Among KSHV-infected individuals, the risk of KS is much higher in those with human immunodeficiency-1 (HIV-1) infection than among those with other types of immunosuppression, suggesting a direct action of HIV-1 on KSHV replication. We show in our report that BC-3 cells, a chronically KSHV-infected B-cell line of a PEL origin, are permissive to HIV-1, offering a new tool for studying the interactions between these 2 viruses. In these cells, HIV-1 infection leads to reactivation of latent KSHV genomes, as demonstrated by the expression of KSHV lytic viral mRNAs. Although recombinant HIV-1 gp120 fails to enhance herpesvirus expression, transient transfection of the HIV-1 trans-activator Tat suffices to reactivate latent KSHV. By showing that HIV-1 infection directly reactivates latent KSHV, our results suggest a direct role of HIV-1 in the onset of KS in coinfected individuals.

Severe perturbations of the blood T cell repertoire in polymyositis, but not dermatomyositis patients

Polymyositis and dermatomyositis are diseases characterized by muscle weakness and muscle inflammatory infiltrates. Their pathogenesis remains unclear. A central role for endomysial autoaggressive CD8(+) T cells is suspected in polymyositis and for perivascular B cells in dermatomyositis. We compared the T cell repertoire of 10 polymyositis and 10 dermatomyositis patients by immunoscope, a method providing a global assessment of the T cell repertoire and a sensitive detection of clonal T cell expansions. Samples were analyzed qualitatively and quantitatively in the blood (unsorted cells and CD4(+) and CD8(+) cells) and in muscle infiltrates. Dramatic perturbations of the T cell repertoire were observed in the blood of polymyositis but not dermatomyositis patients (p < 0.0005), the latter being undistinguishable from controls. These perturbations were due to oligoclonal expansions of CD8(+) T cells and most blood clonal expansions were also found in muscle. These results indicate that the pathogenesis of polymyositis and dermatomyositis is different and reinforce the view that polymyositis but not dermatomyositis is an autoimmune CD8(+) T cell-mediated disease. Moreover, this method may be helpful for the differential diagnosis of polymyositis and dermatomyositis and for noninvasive follow-up of polymyositis patients.

Variable constraints on the principal immunodominant domain of the transmembrane glycoprotein of human immunodeficiency virus type 1

Lentiviruses have in their transmembrane glycoprotein (TM) a highly immunogenic structure referred to as the principal immunodominant domain (PID). The PID forms a loop of 5 to 7 amino acids between two conserved cysteines. Previous studies showed that envelope (Env) glycoprotein functions of feline immunodeficiency virus (FIV) could be retained after extensive mutation of the PID loop sequence, in spite of its high conservation. In order to compare Env function in different lentiviruses, either random mutations were introduced in the PID loop sequence of human immunodeficiency virus type 1 (HIV-1) or the entire HIV-1 PID loop was replaced by the corresponding PID loop of FIV or simian immunodeficiency virus (SIV). In the macrophage-tropic HIV-1 ADA Env, mutations impaired the processing of the gp160 Env precursor, thereby abolishing viral infectivity. However, 6 of the 108 random Env mutants that were screened retained the capacity to induce cell membrane fusion. The SIV and FIV sequences and five random mutations were then introduced in the context of T-cell-line-adapted HIV-1 LAI which, although phenotypically distant from HIV-1 ADA, has an identical PID loop sequence. In contrast to the situation for HIV-1 ADA mutants, the cleavage of the Env precursor was unaffected in most HIV-1 LAI mutants. Such mutations, however, resulted in increased shedding of the gp120 surface glycoprotein (SU) from the gp41 TM. The HIV-1 LAI Env mutants showed high fusogenic efficiency. Three Env mutants retained the capacity to mediate virus entry in target cells, although less efficiently than the wild-type Env, and allowed the reconstitution of infectious molecular clones. These results indicated that in HIV-1, like FIV, the conserved PID sequence can be changed without impairing Env function. However, functional constraints on the PID of HIV-1 vary depending on the structural context of Env, presumably in relation to the role of the PID in the interaction of the SU and TM subunits and the stability of the Env complex.

Shared usage of the chemokine receptor CXCR4 by primary and laboratory-adapted strains of feline immunodeficiency virus

Strains of the feline immunodeficiency virus (FIV) presently under investigation exhibit distinct patterns of in vitro tropism. In particular, the adaptation of FIV for propagation in Crandell feline kidney (CrFK) cells results in the selection of strains capable of forming syncytia with cell lines of diverse species origin. The infection of CrFK cells by CrFK-adapted strains appears to require the chemokine receptor CXCR4 and is inhibited by its natural ligand, stromal cell-derived factor 1alpha (SDF-1alpha). Here we found that inhibitors of CXCR4-mediated infection by human immunodeficiency virus type I (HIV-1), such as the bicyclam AMD3100 and short peptides derived from the amino-terminal region of SDF-1alpha, also blocked infection of CrFK by FIV. Nevertheless, we observed differences in the ranking order of the peptides as inhibitors of FIV and HIV-1 and showed that such differences are related to the species origin of CXCR4 and not that of the viral envelope. These results suggest that, although the envelope glycoproteins of FIV and HIV-1 are substantially divergent, FIV and HIV-1 interact with CXCR4 in a highly similar manner. We have also addressed the role of CXCR4 in the life cycle of primary isolates of FIV. Various CXCR4 ligands inhibited infection of feline peripheral blood mononuclear cells (PBMC) by primary FIV isolates in a concentration-dependent manner. These ligands also blocked the viral transduction of feline PBMC by pseudotyped viral particles when infection was mediated by the envelope glycoprotein of a primary FIV isolate but not by the G protein of vesicular stomatitis virus, indicating that they act at an envelope-mediated step and presumably at viral entry. These findings strongly suggest that primary and CrFK-adapted strains of FIV, despite disparate in vitro tropisms, share usage of CXCR4.