Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

Vascular mimicry as a facilitator of melanoma brain metastasis

Melanoma has the highest propensity among solid tumors to metastasize to the brain. Melanoma brain metastases (MBM) are a leading cause of death in melanoma and affect 40-60% of patients with late-stage disease. Therefore, uncovering the molecular mechanisms behind MBM is necessary to enhance therapeutic interventions. Vascular mimicry (VM) is a form of neovascularization linked to invasion, increased risk of metastasis, and poor prognosis in many tumor types, but its significance in MBM remains poorly understood. We found that VM density is elevated in MBM compared to paired extracranial specimens and is associated with tumor volume and CNS edema. In addition, our studies indicate a relevant role of YAP and TAZ, two transcriptional co-factors scarcely studied in melanoma, in tumor cell-vasculogenesis and in brain metastasis. We recently demonstrated activation of the Hippo tumor suppressor pathway and increased degradation of its downstream targets YAP and TAZ in a metastasis impaired cell line model. In the current study we establish the utility of anti-YAP/TAZ therapy in mouse models of metastatic melanoma whereby treatment effectively inhibits VM and prolongs survival of mice with MBM. The data presented herein suggest that VM may be an important and targetable mechanism in melanoma and that VM inhibition might be useful for treating MBM, an area of high unmet clinical need, thus having important implications for future treatment regimens for these patients.

Treatment of Stage III Resectable Melanoma-Adjuvant and Neoadjuvant Approaches

ABSTRACT

Patients with stage III resectable melanoma carry a high risk of melanoma recurrence that ranges from approximately 40% to 90% at 5 years following surgical management alone. Postoperative systemic adjuvant therapy targets residual micrometastatic disease that could be the source of future recurrence and death from melanoma. Randomized phase III adjuvant trials reported significant improvements in overall survival with high-dose interferon α in 2 of 3 studies (compared with observation and GMK ganglioside vaccine) and with anti-cytotoxic T-lymphocyte antigen 4 ipilimumab at 10 mg/kg compared with placebo and ipilimumab 3 mg/kg compared with high-dose interferon α. In the modern era, more recent phase III trials demonstrated significant recurrence-free survival improvements with anti-programmed cell death protein 1, pembrolizumab, and BRAF-MEK inhibitor combination dabrafenib-trametinib (for BRAF mutant melanoma) versus placebo. Furthermore, anti-programmed cell death protein 1, nivolumab and pembrolizumab have both been shown to significantly improve recurrence-free survival as compared with ipilimumab 10 mg/kg. For melanoma patients with clinically or radiologically detectable locoregionally advanced disease, emerging data support an important role for preoperative systemic neoadjuvant therapy. Importantly, a recent cooperative group trial (S1801) reported superior event-free survival rates with neoadjuvant versus adjuvant therapy. Collectively, current data from neoadjuvant immunotherapy and targeted therapy trials support a future change in clinical practice in favor of neoadjuvant therapy for eligible melanoma patients.

Antitumor activity of the new tyrphostin briva against BRAFV600E-mutant colorectal carcinoma cells

Because of a reduced sensitivity of BRAF-mutant colorectal cancers to BRAF inhibitor treatment when compared with BRAF-mutant melanoma, it is essential to develop efficient drugs to cope with this disease. The new 2-(4-bromophenyl)-3-arylacrylonitrile compound Briva was prepared in one step from commercially available starting compounds. Briva and two known thiophene analogs (Thio-Iva and Thio-Dam) were tested for their cytotoxic activity against various tumor cell lines including colorectal and breast cancer cells. The antitumor activities of the test compounds were assessed in vitro via the MTT assay, DAPI staining of nuclei, RT-PCR and immunoblotting, wound healing, clonogenic assay, collagen I adhesion assay, and kinase inhibition assays. A selective activity of Briva was observed against BRAFV600E-mutant HT-29 and COLO-201 colorectal carcinoma (CRC) cells. Briva caused inhibition of HT-29 clonogenic tumor growth and was found to induce cytotoxicity by activating the intrinsic apoptosis pathway. In addition, Briva reduced HT-29 cell adhesion and migration. Kinase inhibition experiments revealed that Briva inhibits VEGFR2. Thus, Briva can be considered as a promising antitumor compound against BRAFV600E-mutant colon carcinoma by targeting VEGFR2 tyrosine kinase and consequently reducing cell adhesion and metastasis formation.

Efficacy and safety of immune checkpoint inhibitors and targeted therapies in resected melanoma: a systematic review and network meta-analysis

Background: Multiple immune checkpoint inhibitors (ICIs) and targeted therapies have been widely used as adjuvant treatments for high-risk resected melanoma, with unclear comparative efficacy and safety. Methods: PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov were searched from database inception until 6 June 2023. We included RCTs that assess adjuvant ICIs or targeted therapies in high-risk resected melanoma. Frequentist random-effect network meta-analyses (NMA) were performed. The primary outcome was recurrence-free survival (RFS). Results: Eleven trials including 10,712 patients and comparing 10 treatments (nivolumab [Nivo], ipilimumab 3 mg/kg [Ipi3], Ipi10, pembrolizumab [Pemb], vemurafenib [Vemu], bevacizumab [Beva], Nivo + Ipi1, Nivo + Ipi3, dabrafenib plus trametinib [Dab + Tram], and placebo/observation [Pla/Obs]) were included. NMA showed that all treatments showed RFS benefit over placebo/observation except Ipi3 (hazard ratio [HR], 0.78; 95% CI, 0.58-1.05). Combination therapy of Nivo + Ipi3 was the most effective treatment, which significantly improved RFS compared with other treatments. NMA also showed that all treatments were associated with an increased risk of grade 3-5 adverse events over placebo/observation except Nivo (HR, 1.25; 95% CI, 0.87-1.80). NMA suggested that Nivo and Pemb were the two safest treatments except for placebo/observation. Although three combination therapies ranked as the top three in terms of RFS, they did not show significant overall survival benefits compared to monotherapies including Pemb, Nivo, Ipi3, and Ipi10. Conclusion: In this NMA, adjuvant Nivo and Pemb are the preferred options in patients with resected melanoma considering the benefits and harms. Combination therapy of Nivo + Ipi3 may be a promising strategy, but more evidence from phase 3 trials is needed. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=438667, PROSPERO (CRD42023438667).

Systemic Therapy for Melanoma: ASCO Guideline Update

PURPOSE

To provide guidance to clinicians regarding the use of systemic therapy for melanoma.

METHODS

American Society of Clinical Oncology convened an Expert Panel and conducted an updated systematic review of the literature.

RESULTS

The updated review identified 21 additional randomized trials.

UPDATED RECOMMENDATIONS

Neoadjuvant pembrolizumab was newly recommended for patients with resectable stage IIIB to IV cutaneous melanoma. For patients with resected cutaneous melanoma, adjuvant nivolumab or pembrolizumab was newly recommended for stage IIB-C disease and adjuvant nivolumab plus ipilimumab was added as a potential option for stage IV disease. For patients with unresectable or metastatic cutaneous melanoma, nivolumab plus relatlimab was added as a potential option regardless of BRAF mutation status and nivolumab plus ipilimumab followed by nivolumab was preferred over BRAF/MEK inhibitor therapy. Talimogene laherparepvec is no longer recommended as an option for patients with BRAF wild-type disease who have progressed on anti-PD-1 therapy. Ipilimumab- and ipilimumab-containing regimens are no longer recommended for patients with BRAF-mutated disease after progression on other therapies.This full update incorporates the new recommendations for uveal melanoma published in the 2022 Rapid Recommendation Update.Additional information is available at www.asco.org/melanoma-guidelines.

COLUMBUS-AD: phase III study of adjuvant encorafenib + binimetinib in resected stage IIB/IIC BRAF V600-mutated melanoma

Stage IIB/IIC melanoma has a high risk of recurrence after surgical resection. While, for decades, surgery was the only option for high-risk stage II disease in most countries, adjuvant therapies now exist. Anti-programmed cell death protein 1 (PD-1) antibodies significantly improve recurrence-free survival versus placebo in patients with fully resected stage IIB/IIC melanoma. Combined BRAF MEK inhibitor therapy showed benefits in high-risk stage III and advanced disease; however, its role in patients with fully resected stage BRAF-mutated IIB/IIC melanoma is still unknown. Here we describe the rationale and design of the ongoing randomized, placebo-controlled COLUMBUS-AD trial, the first study of a BRAF-MEK inhibitor combination therapy (encorafenib + binimetinib) in patients with BRAF V600-mutated stage IIB/IIC melanoma.

Adjuvant Therapy for High-Risk Melanoma: An In-Depth Examination of the State of the Field

The consideration of systemic adjuvant therapy is recommended for patients with stage IIB-IV melanoma who have undergone surgical resection due to a heightened risk of experiencing melanoma relapse and mortality from melanoma. Adjuvant therapy options tested over the past three decades include high-dose interferon-α, immune checkpoint inhibitors (pembrolizumab, nivolumab), targeted therapy (dabrafenib-trametinib for BRAF mutant melanoma), radiotherapy and chemotherapy. Most of these therapies have been demonstrated to enhance relapse-free survival (RFS) but with limited to no impact on overall survival (OS), as reported in randomized trials. In contemporary clinical practice, the adjuvant treatment approach for surgically resected stage III-IV melanoma has undergone a notable shift towards the utilization of nivolumab, pembrolizumab, and BRAF-MEK inhibitors, such as dabrafenib plus trametinib (specifically for BRAF mutant melanoma) due to the significant enhancements in RFS observed with these treatments. Pembrolizumab has obtained regulatory approval in the United States to treat resected stage IIB-IIC melanoma, while nivolumab is currently under review for the same indication. This review comprehensively analyzes completed phase III adjuvant therapy trials in adjuvant therapy. Additionally, it provides a summary of ongoing trials and an overview of the main challenges and future directions with adjuvant therapy.

Circulating galectin-1 delineates response to bevacizumab in melanoma patients and reprograms endothelial cell biology

Blockade of vascular endothelial growth factor (VEGF) signaling with bevacizumab, a humanized anti-VEGF monoclonal antibody (mAb), or with receptor tyrosine kinase inhibitors, has improved progression-free survival and, in some indications, overall survival across several types of cancers by interrupting tumor angiogenesis. However, the clinical benefit conferred by these therapies is variable, and tumors from treated patients eventually reinitiate growth. Previously we demonstrated, in mouse tumor models, that galectin-1 (Gal1), an endogenous glycan-binding protein, preserves angiogenesis in anti-VEGF-resistant tumors by co-opting the VEGF receptor (VEGFR)2 signaling pathway in the absence of VEGF. However, the relevance of these findings in clinical settings is uncertain. Here, we explored, in a cohort of melanoma patients from AVAST-M, a multicenter, open-label, randomized controlled phase 3 trial of adjuvant bevacizumab versus standard surveillance, the role of circulating plasma Gal1 as part of a compensatory mechanism that orchestrates endothelial cell programs in bevacizumab-treated melanoma patients. We found that increasing Gal1 levels over time in patients in the bevacizumab arm, but not in the observation arm, significantly increased their risks of recurrence and death. Remarkably, plasma Gal1 was functionally active as it was able to reprogram endothelial cell biology, promoting migration, tubulogenesis, and VEGFR2 phosphorylation. These effects were prevented by blockade of Gal1 using a newly developed fully human anti-Gal1 neutralizing mAb. Thus, using samples from a large-scale clinical trial from stage II and III melanoma patients, we validated the clinical relevance of Gal1 as a potential mechanism of resistance to bevacizumab treatment.

Identifying the Transcriptional Drivers of Metastasis Embedded within Localized Melanoma

In melanoma, predicting which tumors will ultimately metastasize guides treatment decisions. Transcriptional signatures of primary tumors have been utilized to predict metastasis, but which among these are driver or passenger events remains unclear. We used data from the adjuvant AVAST-M trial to identify a predictive gene signature in localized tumors that ultimately metastasized. Using a zebrafish model of primary melanoma, we interrogated the top genes from the AVAST-M signature in vivo. This identified GRAMD1B, a cholesterol transfer protein, as a bona fide metastasis suppressor, with a majority of knockout animals rapidly developing metastasis. Mechanistically, excess free cholesterol or its metabolite 27-hydroxycholesterol promotes invasiveness via activation of an AP-1 program, which is associated with increased metastasis in humans. Our data demonstrate that the transcriptional seeds of metastasis are embedded within localized tumors, suggesting that early targeting of these programs can be used to prevent metastatic relapse.

SIGNIFICANCE

We analyzed human melanoma transcriptomics data to identify a gene signature predictive of metastasis. To rapidly test clinical signatures, we built a genetic metastasis platform in adult zebrafish and identified GRAMD1B as a suppressor of melanoma metastasis. GRAMD1B-associated cholesterol overload activates an AP-1 program to promote melanoma invasion. This article is highlighted in the In This Issue feature, p. 1.

WNT5A-ROR2 axis mediates VEGF dependence of BRAF mutant melanoma

Purpose

Despite recent advances, approximately 50% of patient with metastatic melanoma eventually succumb to the disease. Patients with melanomas harboring a BRAF mutation (BRAFMut) have a worse prognosis than those with wildtype (BRAFWT) tumors. Unexpectedly, interim AVAST-M Phase III trial data reported benefit from adjuvant anti-VEGF bevacizumab only in the BRAFMut group. We sought to find mechanisms underpinning this sensitivity.

Methods

We investigated this finding in vitro and in vivo using melanoma cell lines and clones generated by BRAFV600E knock-in on a BRAFWT background.

Results

Compared with BRAFWT cells, isogenic BRAFV600E clones secreted more VEGF and exhibited accelerated growth rates as spheroids and xenografts, which were more vascular and proliferative. Recapitulating AVAST-M findings, bevacizumab affected only BRAFV600E xenografts, inducing significant tumor growth delay, reduced vascularity and increased necrosis. We identified 814 differentially expressed genes in isogenic BRAFV600E/BRAFWT clones. Of 61 genes concordantly deregulated in clinical melanomas ROR2 was one of the most upregulated by BRAFV600E. ROR2 was shown to be RAF-MEK regulated in BRAFV600E cells and its depletion suppressed VEGF secretion down to BRAFWT levels. The ROR2 ligand WNT5A was also overexpressed in BRAFMut melanomas, and in ROR2-overexpressing BRAFV600E cells MEK inhibition downregulated WNT5A and VEGF secretion.

Conclusions

These data implicate WNT5A-ROR2 in VEGF secretion, vascularity, adverse outcomes and bevacizumab sensitivity of BRAFMut melanomas, suggesting that this axis has potential therapeutic relevance.

The role of angiogenesis in melanoma: Clinical treatments and future expectations

The incidence of melanoma has increased rapidly over the past few decades, with mortality accounting for more than 75% of all skin cancers. The high metastatic potential of Melanoma is an essential factor in its high mortality. Vascular angiogenic system has been proved to be crucial for the metastasis of melanoma. An in-depth understanding of angiogenesis will be of great benefit to melanoma treatment and may promote the development of melanoma therapies. This review summarizes the recent advances and challenges of anti-angiogenic agents, including monoclonal antibodies, tyrosine kinase inhibitors, human recombinant Endostatin, and traditional Chinese herbal medicine. We hope to provide a better understanding of the mechanisms, clinical research progress, and future research directions of melanoma.

The roles of TGF-β and VEGF pathways in the suppression of antitumor immunity in melanoma and other solid tumors

Immune checkpoint blockade (ICB) has become well-known in cancer therapy, strengthening the body's antitumor immune response rather than directly targeting cancer cells. Therapies targeting immune inhibitory checkpoints, such as PD-1, PD-L1, and CTLA-4, have resulted in impressive clinical responses across different types of solid tumors. However, as with other types of cancer treatments, ICB-based immunotherapy is hampered by both innate and acquired drug resistance. We previously reported the enrichment of gene signatures associated with wound healing, epithelial-to-mesenchymal, and angiogenesis processes in the tumors of patients with innate resistance to PD-1 checkpoint antibody therapy; we termed these the Innate Anti-PD-1 Resistance Signatures (IPRES). The TGF-β and VEGFA pathways emerge as the dominant drivers of IPRES-associated processes. Here, we review these pathways' functions, their roles in immunosuppression, and the currently available therapies that target them. We also discuss recent developments in the targeting of TGF-β using a specific antibody class termed trap antibody. The application of trap antibodies opens the promise of localized targeting of the TGF-β and VEGFA pathways within the tumor microenvironment. Such specificity may offer an enhanced therapeutic window that enables suppression of the IPRES processes in the tumor microenvironment while sparing the normal homeostatic functions of TGF-β and VEGFA in healthy tissues.

Melanoma Tumour Vascularization and Tissue-Resident Endothelial Progenitor Cells

Simple Summary

Melanoma is the most aggressive and potentially lethal form of skin cancer. Research over recent decades has highlighted the role of tumour vasculature in altering the metabolic function of cancer cells, infiltration of immune cells, and cancer cell dissemination. However, variations in the modes of vessel formation in melanoma have made this process difficult to target. In particular, the role of endothelial progenitor cells in melanoma vascularization-promoting vasculogenesis begins to be understood. Progenitor recruitment, vessel formation, and paracrine activity are among the steps contributing to tumour metastasis and affecting the impact of anti-angiogenic drugs, as detailed in this review.

Abstract

The aggressiveness of solid cancers, such as melanoma, relies on their metastatic potential. It has become evident that this key cause of mortality is largely conferred by the tumour-associated stromal cells, especially endothelial cells. In addition to their essential role in the formation of the tumour vasculature, endothelial cells significantly contribute to the establishment of the tumour microenvironment, thus enabling the dissemination of cancer cells. Melanoma tumour vascularization occurs through diverse biological processes. Vasculogenesis is the formation of de novo blood vessels from endothelial progenitor cells (EPCs), and recent research has shown the role of EPCs in melanoma tumour vascularization. A more detailed understanding of the complex role of EPCs and how they contribute to the abnormal vessel structures in tumours is of importance. Moreover, anti-angiogenic drugs have a limited effect on melanoma tumour vascularization, and the role of these drugs on EPCs remains to be clarified. Overall, targeting cancer vasculature remains a challenge, and the role of anti-angiogenic drugs and combination therapies in melanoma, a focus of this review, is an area of extensive exploration.

ROS-Mediated Anti-Angiogenic Activity of Cerium Oxide Nanoparticles in Melanoma Cells

Angiogenesis plays a key role in cancer progression, including transition to the metastatic phase via reactive oxygen species (ROS)-dependent pathways, among others. Antivascular endothelial growth factor (VEGF) antibodies have been trialed as an anti-angiogenic therapy for cancer but are associated with high cost, limited efficacy, and side effects. Cerium oxide nanoparticles (nanoceria) are promising nanomaterials for biomedical applications due to their ability to modulate intracellular ROS. Nanoceria can be produced by a range of synthesis methods, with chemical precipitation as the most widely explored. It has been reported that chemical precipitation can fine-tune primary particle size where a limited number of synthesis parameters were varied. Here, we explore the effect of temperature, precipitating agent concentration and rate of addition, stirring rate, and surfactant concentration on nanoceria primary particle size using a fractional factorial experimental design approach. We establish a robust synthesis method for faceted nanoceria with primary particle diameters of 5-6 nm. The nanoceria are not cytotoxic to a human melanoma cell line (Mel1007) at doses up to 400 μg/mL and are dose-dependently internalized by the cells. The intracellular ROS level for some cells that internalized the nanoceria is reduced, which correlates with a dose-dependent reduction in angiogenic gene expression including VEGF. These findings contribute to our knowledge of the anti-angiogenic effects of nanoceria and help to develop our understanding of potentially new anti-angiogenic agents for combination cancer therapies.

Vitamin D Enhances Anticancer Properties of Cediranib, a VEGFR Inhibitor, by Modulation of VEGFR2 Expression in Melanoma Cells

Regardless of the recent groundbreaking introduction of personalized therapy, melanoma continues to be one of the most lethal skin malignancies. Still, a substantial proportion of patients either fail to respond to the therapy or will relapse over time, representing a challenging clinical problem. Recently, we have shown that vitamin D enhances the effectiveness of classical chemotherapeutics in the human malignant melanoma A375 cell line. In search for new combination strategies and adjuvant settings to improve melanoma patient outcomes in the current study, the effects of cediranib (AZD2171), an oral tyrosine kinase inhibitor of VEGFR1-3, PDGFR, and c-KIT, used in combination either with 1,25(OH)₂D₃ or with low-calcemic analog calcipotriol were tested on four human malignant melanoma cell lines (A375, MNT-1, RPMI-7951, and SK-MEL-28). Melanoma cells were pretreated with vitamin D and subsequently exposed to cediranib. We observed a marked decrease in melanoma cell proliferation (A375 and SK-MEL-28), G2/M cell cycle arrest, and a significant decrease in melanoma cell mobility in experimental conditions used (A375). Surprisingly, concurrently with a very desirable decrease in melanoma cell proliferation and mobility, we noticed the upregulation of VEGFR2 at both protein and mRNA levels. No effect of vitamin D was observed in MNT-1 and RPMI-7951 melanoma cells. It seems that vitamin D derivatives enhance cediranib efficacy by modulation of VEGFR2 expression in melanoma cells expressing VEGFR2. In conclusion, our experiments demonstrated that vitamin D derivatives hold promise as novel adjuvant candidates to conquer melanoma, especially in patients suffering from vitamin D deficiency. However, further extensive research is indispensable to reliably assess their potential benefits for melanoma patients.

Melanoma trials that defined surgical management: Brief overview of current/upcoming adjuvant/neoadjuvant trials

Adjuvant systemic therapy for cutaneous melanoma has experienced practice-changing shifts over the last decade. The successful results of immunotherapies and targeted therapies in the metastatic setting have allowed for investigative trials of the same therapies in the adjuvant and now neoadjuvant setting, with the potential for improved clinical outcomes in patients with high risk resected Stage III and IV melanoma.

Interacting Genetic Lesions of Melanoma in the Tumor Microenvironment: Defining a Viable Therapy

Melanoma is the most aggressive form of skin cancer with an estimated 106,110 newly diagnosed cases in the United States of America in 2021 leading to an approximated 7180 melanoma-induced deaths. Cancer typically arises from an accumulation of somatic mutations and can be associated with mutagenic or carcinogenic exposure. A key characteristic of melanoma is the extensive somatic mutation rate of 16.8 mutations/Mb, which is largely attributed to UV exposure. Bearing the highest mutational load, many of them occur in key driver pathways, most commonly the BRAFV600E in the mitogen-activated protein kinase (MAPK) pathway. This driver mutation is targeted clinically with FDA-approved therapies using small molecule inhibitors of oncogenic BRAFV600E and MEK, which has greatly expanded therapeutic intervention following a melanoma diagnosis. Up until 2011, therapeutic options for metastatic melanoma were limited, and treatment typically fell under the spectrum of surgery, radiotherapy, and chemotherapy.Attributed to the extensive mutation rate, as well as having the highest number of neoepitopes, melanoma is deemed to be extremely immunogenic. However, despite this highly immunogenic nature, melanoma is notorious for inducing an immunosuppressive microenvironment which can be relieved by checkpoint inhibitor therapy. The two molecules currently approved clinically are ipilimumab and nivolumab, which target the molecules CTLA-4 and PD-1, respectively.A plethora of immunomodulatory molecules exist, many with redundant functions. Additionally, these molecules are expressed not only by immune cells but also by tumor cells within the tumor microenvironment. Tumor profiling of these cell surface checkpoint molecules is necessary to optimize a clinical response. The presence of immunomodulatory molecules in melanoma, using data from The Cancer Genome Atlas and validation of expression in two model systems, human melanoma tissues and patient-derived melanoma cells, revealed that the expression levels of B and T lymphocyte attenuator (BTLA), TIM1, and CD226, concurrently with the BRAFV600E mutation status, significantly dictated overall survival in melanoma patients. These molecules, along with herpesvirus entry mediator (HVEM) and CD160, two molecules that are a part of the HVEM/BTLA/CD160 axis, had a higher expression in human melanoma tissues when compared to normal skin melanocytes and have unique roles to play in T cell activation. New links are being uncovered between the expression of immunomodulatory molecules and the BRAFV600E genetic lesion in melanoma. Small molecule inhibitors of the MAPK pathway regulate the surface expression of this multifaceted molecule, making BTLA a promising target for immuno-oncology to be targeted in combination with small molecule inhibitors, potentially alleviating T regulatory cell activation and improving patient prognosis.

Clinical Significance of Distant Metastasis-Free Survival (DMFS) in Melanoma: A Narrative Review from Adjuvant Clinical Trials

Cutaneous melanoma is the most dangerous skin cancer, with high death rates in advanced stages. To assess the impact of each treatment on patient outcomes, most studies use relapse-free survival (RFS) as a primary endpoint and distant metastasis-free survival (DMFS) as a secondary endpoint. The aim of this narrative review of the main adjuvant studies for resected stage III/IV melanoma, with a specific focus on DMFS, is to evaluate DMFS trends and their potential association with RFS, identify which treatments are possibly associated with better outcomes in terms of DMFS and their potential predictive factors, and discuss DMFS trends in terms of patient management in daily practice. We outline the impact of each available treatment option on DMFS and RFS according to the years of follow-up and compare data from different studies. Overall, the trends of DMFS closely follow those of RFS, with most patients relapsing at visceral rather than regional sites. As it captures the burden of patients who develop distant relapse, DMFS could be considered a primary endpoint, in addition to RFS, in adjuvant trials, identifying patients whose relapse is associated with a worse prognosis and who may need further systemic treatment.

Cooperation between melanoma cell states promotes metastasis through heterotypic cluster formation

Melanomas can have multiple coexisting cell states, including proliferative (PRO) versus invasive (INV) subpopulations that represent a "go or grow" trade-off; however, how these populations interact is poorly understood. Using a combination of zebrafish modeling and analysis of patient samples, we show that INV and PRO cells form spatially structured heterotypic clusters and cooperate in the seeding of metastasis, maintaining cell state heterogeneity. INV cells adhere tightly to each other and form clusters with a rim of PRO cells. Intravital imaging demonstrated cooperation in which INV cells facilitate dissemination of less metastatic PRO cells. We identified the TFAP2 neural crest transcription factor as a master regulator of clustering and PRO/INV states. Isolation of clusters from patients with metastatic melanoma revealed a subset with heterotypic PRO-INV clusters. Our data suggest a framework for the co-existence of these two divergent cell populations, in which heterotypic clusters promote metastasis via cell-cell cooperation.

Adjuvant systemic treatment for high-risk resected non-cutaneous melanomas: What is the evidence?

Non-cutaneous melanomas (mucosal, uveal, leptomeningeal, unknown primaries) represent around 5-10 % of all melanoma diagnoses. Non-cutaneous melanomas demonstrate differences in tumour biology, generally present with more advanced stages and have an overall poorer prognosis compared to skin melanomas. The cornerstone of their treatment is surgery followed by radiotherapy in some cases. Unfortunately, in many of these patients their melanoma will recur. Adjuvant therapy for non-cutaneous melanomas remains controversial. To date, almost all of the tested adjuvant agents have failed to demonstrate any benefit; the two randomised positive trials were criticized for methodological reasons, small sample size and conflicting results. The aim of this review is to assess the current evidence on systemic adjuvant treatments for high-risk resected non-cutaneous melanomas. We also provide a summary table with the currently recruiting clinical trials in these settings and we discuss some strategies to improve trial design in this particularly niche area of oncology.

TEM8 marks neovasculogenic tumor-initiating cells in triple-negative breast cancer

Enhanced neovasculogenesis, especially vasculogenic mimicry (VM), contributes to the development of triple-negative breast cancer (TNBC). Breast tumor-initiating cells (BTICs) are involved in forming VM; however, the specific VM-forming BTIC population and the regulatory mechanisms remain undefined. We find that tumor endothelial marker 8 (TEM8) is abundantly expressed in TNBC and serves as a marker for VM-forming BTICs. Mechanistically, TEM8 increases active RhoC level and induces ROCK1-mediated phosphorylation of SMAD5, in a cascade essential for promoting stemness and VM capacity of breast cancer cells. ASB10, an estrogen receptor ERα trans-activated E3 ligase, ubiquitylates TEM8 for degradation, and its deficiency in TNBC resulted in a high homeostatic level of TEM8. In this work, we identify TEM8 as a functional marker for VM-forming BTICs in TNBC, providing a target for the development of effective therapies against TNBC targeting both BTIC self-renewal and neovasculogenesis simultaneously.

Vasculogenic mimicry (VM) contributes to the development of triple-negative breast cancer. In this study, the authors show that TEM8 is expressed in VM-forming breast cancer stem cells and it promotes stemness and VM differentiation capacity through a RhoC/ROCK1/SMAD5 axis

Antibody-Based Targeted Interventions for the Diagnosis and Treatment of Skin Cancers

BACKGROUND

Cutaneous malignancies most commonly arise from skin epidermal cells. These cancers may rapidly progress from benign to a metastatic phase. Surgical resection represents the gold standard therapeutic treatment of non-metastatic skin cancer while chemo- and/or radiotherapy are often used against metastatic tumors. However, these therapeutic treatments are limited by the development of resistance and toxic side effects, resulting from the passive accumulation of cytotoxic drugs within healthy cells.

OBJECTIVE

This review aims to elucidate how the use of monoclonal Antibodies (mAbs) targeting specific Tumor Associated Antigens (TAAs) is paving the way to improved treatment. These mAbs are used as therapeutic or diagnostic carriers that can specifically deliver cytotoxic molecules, fluorophores or radiolabels to cancer cells that overexpress specific target antigens.

RESULTS

mAbs raised against TAAs are widely in use for e.g. differential diagnosis, prognosis and therapy of skin cancers. Antibody-Drug Conjugates (ADCs) particularly show remarkable potential. The safest ADCs reported to date use non-toxic photo-activatable Photosensitizers (PSs), allowing targeted Photodynamic Therapy (PDT) resulting in targeted delivery of PS into cancer cells and selective killing after light activation without harming the normal cell population. The use of near-infrared-emitting PSs enables both diagnostic and therapeutic applications upon light activation at the specific wavelengths.

CONCLUSION

Antibody-based approaches are presenting an array of opportunities to complement and improve current methods employed for skin cancer diagnosis and treatment.

Advances in Targeting Cutaneous Melanoma

Simple Summary

Cutaneous Melanoma (CM), arising from pigment-producing melanocytes in the skin, is an aggressive cancer with high metastatic potential. While cutaneous melanoma represents only a fraction of all skin cancers (<5%), it accounts for most skin-cancer-related deaths worldwide. Immune checkpoint inhibition has been the first therapeutic approach to significantly benefit patient survival after treatment. Nevertheless, the immunosuppressive tumor microenvironment and the intrinsic and acquired treatment resistance of melanoma remain crucial challenges. Combining local and systemic treatment offers the potential to augment therapeutic response and overcome resistance, although, complex drug combinations can harbor an increased risk of immune-related adverse events. The aim of this review is to give current insight into studies combining systemic and local therapeutic approaches to overcome drug resistance, prime melanoma cells for therapy, and improve overall treatment response in CM patients.

Abstract

To date, the skin remains the most common cancer site among Caucasians in the western world. The complex, layered structure of human skin harbors a heterogenous population of specialized cells. Each cell type residing in the skin potentially gives rise to a variety of cancers, including non-melanoma skin cancer, sarcoma, and cutaneous melanoma. Cutaneous melanoma is known to exacerbate and metastasize if not detected at an early stage, with mutant melanomas tending to acquire treatment resistance over time. The intricacy of melanoma thus necessitates diverse and patient-centered targeted treatment options. In addition to classical treatment through surgical intervention and radio- or chemotherapy, several systemic and intratumoral immunomodulators, pharmacological agents (e.g., targeted therapies), and oncolytic viruses are trialed or have been recently approved. Moreover, utilizing combinations of immune checkpoint blockade with targeted, oncolytic, or anti-angiogenic approaches for patients with advanced disease progression are promising approaches currently under pre-clinical and clinical investigation. In this review, we summarize the current ‘state-of-the-art’ as well as discuss emerging agents and regimens in cutaneous melanoma treatment.

RTK Inhibitors in Melanoma: From Bench to Bedside

MAPK (mitogen activated protein kinase) and PI3K/AKT (Phosphatidylinositol-3-Kinase and Protein Kinase B) pathways play a key role in melanoma progression and metastasis that are regulated by receptor tyrosine kinases (RTKs). Although RTKs are mutated in a small percentage of melanomas, several receptors were found up regulated/altered in various stages of melanoma initiation, progression, or metastasis. Targeting RTKs remains a significant challenge in melanoma, due to their variable expression across different melanoma stages of progression and among melanoma subtypes that consequently affect response to treatment and disease progression. In this review, we discuss in details the activation mechanism of several key RTKs: type III: c-KIT (mast/stem cell growth factor receptor); type I: EGFR (Epidermal growth factor receptor); type VIII: HGFR (hepatocyte growth factor receptor); type V: VEGFR (Vascular endothelial growth factor), structure variants, the function of their structural domains, and their alteration and its association with melanoma initiation and progression. Furthermore, several RTK inhibitors targeting the same receptor were tested alone or in combination with other therapies, yielding variable responses among different melanoma groups. Here, we classified RTK inhibitors by families and summarized all tested drugs in melanoma indicating the rationale behind the use of these drugs in each melanoma subgroups from preclinical studies to clinical trials with a specific focus on their purpose of treatment, resulted effect, and outcomes.

BRAF Gene and Melanoma: Back to the Future

As widely acknowledged, 40-50% of all melanoma patients harbour an activating BRAF mutation (mostly BRAF V600E). The identification of the RAS-RAF-MEK-ERK (MAP kinase) signalling pathway and its targeting has represented a valuable milestone for the advanced and, more recently, for the completely resected stage III and IV melanoma therapy management. However, despite progress in BRAF-mutant melanoma treatment, the two different approaches approved so far for metastatic disease, immunotherapy and BRAF+MEK inhibitors, allow a 5-year survival of no more than 60%, and most patients relapse during treatment due to acquired mechanisms of resistance. Deep insight into BRAF gene biology is fundamental to describe the acquired resistance mechanisms (primary and secondary) and to understand the molecular pathways that are now being investigated in preclinical and clinical studies with the aim of improving outcomes in BRAF-mutant patients.

CRISPR activation screen in mice identifies novel membrane proteins enhancing pulmonary metastatic colonisation

Melanoma represents ~5% of all cutaneous malignancies, yet accounts for the majority of skin cancer deaths due to its propensity to metastasise. To develop new therapies, novel target molecules must to be identified and the accessibility of cell surface proteins makes them attractive targets. Using CRISPR activation technology, we screened a library of guide RNAs targeting membrane protein-encoding genes to identify cell surface molecules whose upregulation enhances the metastatic pulmonary colonisation capabilities of tumour cells in vivo. We show that upregulated expression of the cell surface protein LRRN4CL led to increased pulmonary metastases in mice. Critically, LRRN4CL expression was elevated in melanoma patient samples, with high expression levels correlating with decreased survival. Collectively, our findings uncover an unappreciated role for LRRN4CL in the outcome of melanoma patients and identifies a potential therapeutic target and biomarker.

Tumour gene expression signature in primary melanoma predicts long-term outcomes

Adjuvant systemic therapies are now routinely used following resection of stage III melanoma, however accurate prognostic information is needed to better stratify patients. We use differential expression analyses of primary tumours from 204 RNA-sequenced melanomas within a large adjuvant trial, identifying a 121 metastasis-associated gene signature. This signature strongly associated with progression-free (HR = 1.63, p = 5.24 × 10-5) and overall survival (HR = 1.61, p = 1.67 × 10-4), was validated in 175 regional lymph nodes metastasis as well as two externally ascertained datasets. The machine learning classification models trained using the signature genes performed significantly better in predicting metastases than models trained with clinical covariates (pAUROC = 7.03 × 10-4), or published prognostic signatures (pAUROC < 0.05). The signature score negatively correlated with measures of immune cell infiltration (ρ = -0.75, p < 2.2 × 10-16), with a higher score representing reduced lymphocyte infiltration and a higher 5-year risk of death in stage II melanoma. Our expression signature identifies melanoma patients at higher risk of metastases and warrants further evaluation in adjuvant clinical trials.

Dissecting the Lymphatic System to Predict Melanoma Metastasis

Melanoma is the most lethal form of skin cancer in the United States. Current American Joint Committee on Cancer (AJCC) staging uses Breslow depth and ulceration as the two primary tumor factors that predict metastatic risk in cutaneous melanoma. Early disease stages are generally associated with high survival rates. However, in some cases, patients with thin melanomas develop advanced disease, suggesting other factors may contribute to the metastatic potential of an individual patient’s melanoma. This review focuses on the role of the lymphatic system in the metastasis of cutaneous melanoma, from recent discoveries in mechanisms of lymphangiogenesis to elements of the lymphatic system that ultimately may aid clinicians in determining which patients are at highest risk. Ultimately, this review highlights the need to integrate pathological, morphological, and molecular characteristics of lymphatics into a “biomarker” for metastatic potential.

Systemic Therapy for Melanoma: ASCO Guideline

PURPOSE

To provide guidance to clinicians regarding the use of systemic therapy for melanoma.

METHODS

ASCO convened an Expert Panel and conducted a systematic review of the literature.

RESULTS

A systematic review, one meta-analysis, and 34 additional randomized trials were identified. The published studies included a wide range of systemic therapies in cutaneous and noncutaneous melanoma.

RECOMMENDATIONS

In the adjuvant setting, nivolumab or pembrolizumab should be offered to patients with resected stage IIIA/B/C/D BRAF wild-type cutaneous melanoma, while either of those two agents or the combination of dabrafenib and trametinib should be offered in BRAF-mutant disease. No recommendation could be made for or against the use of neoadjuvant therapy in cutaneous melanoma. In the unresectable/metastatic setting, ipilimumab plus nivolumab, nivolumab alone, or pembrolizumab alone should be offered to patients with BRAF wild-type cutaneous melanoma, while those three regimens or combination BRAF/MEK inhibitor therapy with dabrafenib/trametinib, encorafenib/binimetinib, or vemurafenib/cobimetinib should be offered in BRAF-mutant disease. Patients with mucosal melanoma may be offered the same therapies recommended for cutaneous melanoma. No recommendation could be made for or against specific therapy for uveal melanoma. Additional information is available at www.asco.org/melanoma-guidelines.

A non-linear optimisation method to extract summary statistics from Kaplan-Meier survival plots using the published P value

Background

Meta-analyses of studies evaluating survival (time-to-event) outcomes are a powerful technique to assess the strength of evidence for a given disease or treatment. However, these studies rely on the adequate reporting of summary statistics in the source articles to facilitate further analysis. Unfortunately, many studies, especially within the field of prognostic research do not report such statistics, making secondary analyses challenging. Consequently, methods have been developed to infer missing statistics from the commonly published Kaplan-Meier (KM) plots but are liable to error especially when the published number at risk is not included.

Methods

We therefore developed a method using non-linear optimisation (nlopt) that only requires the KM plot and the commonly published P value to better estimate the underlying censoring pattern. We use this information to then calculate the natural logarithm of the hazard ratio (ln (HR)) and its variance (var) ln (HR), statistics important for meta-analyses.

Results

We compared this method to the Parmar method which also does not require the number at risk to be published. In a validation set consisting of 13 KM studies, a statistically significant improvement in calculating ln (HR) when using an exact P value was obtained (mean absolute error 0.014 vs 0.077, P = 0.003). Thus, when the true HR has a value of 1.5, inference of the HR using the proposed method would set limits between 1.49/1.52, an improvement of the 1.39/1.62 limits obtained using the Parmar method. We also used Monte Carlo simulations to establish recommendations for the number and positioning of points required for the method.

Conclusion

The proposed non-linear optimisation method is an improvement on the existing method when only a KM plot and P value are included and as such will enhance the accuracy of meta-analyses performed for studies analysing time-to-event outcomes. The nlopt source code is available, as is a simple-to-use web implementation of the method.

sFRP2 Supersedes VEGF as an Age-related Driver of Angiogenesis in Melanoma, Affecting Response to Anti-VEGF Therapy in Older Patients

PURPOSE

Angiogenesis is thought to be critical for tumor metastasis. However, inhibiting angiogenesis using antibodies such as bevacizumab (Avastin), has had little impact on melanoma patient survival. We have demonstrated that both angiogenesis and metastasis are increased in older individuals, and therefore sought to investigate whether there was an age-related difference in response to bevacizumab, and if so, what the underlying mechanism could be.

EXPERIMENTAL DESIGN

We analyzed data from the AVAST-M trial of 1,343 patients with melanoma treated with bevacizumab to determine whether there is an age-dependent response to bevacizumab. We also examined the age-dependent expression of VEGF and its cognate receptors in patients with melanoma, while using syngeneic melanoma animal models to target VEGF in young versus old mice. We also examined the age-related proangiogenic factor secreted frizzled-related protein 2 (sFRP2) and whether it could modulate response to anti-VEGF therapy.

RESULTS

We show that older patients respond poorly to bevacizumab, whereas younger patients show improvement in both disease-free survival and overall survival. We find that targeting VEGF does not ablate angiogenesis in an aged mouse model, while sFRP2 promotes angiogenesis in vitro and in young mice. Targeting sFRP2 in aged mice successfully ablates angiogenesis, while the effects of targeting VEGF in young mice can be overcome by increasing sFRP2.

CONCLUSIONS

VEGF is decreased during aging, thereby reducing response to bevacizumab. Despite the decrease in VEGF, angiogenesis is increased because of an increase in sFRP2 in the aged tumor microenvironment. These results stress the importance of considering age as a factor for designing targeted therapies.

Adjuvant Therapy for Melanoma: Past, Current, and Future Developments

This review describes the progress that the concept of adjuvant therapies has undergone in the last 50 years and focuses on the most recent development where an adjuvant approach has been scientifically evaluated in melanoma clinical trials. Over the past decade the development of immunotherapies and targeted therapies has drastically changed the treatment of stage IV melanoma patients. These successes led to trials studying the same therapies in the adjuvant setting, in high risk resected stage III and IV melanoma patients. Adjuvant immune checkpoint blockade with anti-CTLA-4 antibody ipilimumab was the first drug to show an improvement in recurrence-free and overall survival but this was accompanied by high severe toxicity rates. Therefore, these results were bypassed by adjuvant treatment with anti-PD-1 agents nivolumab and pembrolizumab and BRAF-directed target therapy, which showed even better recurrence-free survival rates with more favorable toxicity rates. The whole concept of adjuvant therapy may be integrated with the new neoadjuvant approaches that are under investigation through several clinical trials. However, there is still no data available on whether the effective adjuvant therapy that patients finally have at their disposal could be offered to them while waiting for recurrence, sparing at least 50% of them a potentially long-term toxic side effect but with the same rate of overall survival (OS). Adjuvant therapy for melanoma has radically changed over the past few years—anti-PD-1 or BRAF-directed therapy is the new standard of care.

Systemic adjuvant therapy for adult patients at high risk for recurrent melanoma: A systematic review

Cutaneous melanoma is typically treated with wide local excision and, when appropriate, a sentinel node biopsy. Many patients are cured with this approach but for patients who have cancers with high risk features there is a significant risk of local and distant relapse and death. Interferon-based adjuvant therapy was recommended in the past but had modest results with significant toxicity. Recently, new therapies (immune checkpoint inhibitors and targeted therapies) have been found to be effective in the treatment of patients with metastatic melanoma and many of these therapies have been evaluated and found to be effective in the adjuvant treatment of high risk patients with melanoma. This systematic review of adjuvant therapies for cutaneous and mucosal melanoma was conducted for Ontario Health (Cancer Care Ontario) as the basis of a clinical practice guideline to address the question of whether patients with completely resected melanoma should be considered for adjuvant systemic therapy and which adjuvant therapy should be used.

ctDNA monitoring using patient-specific sequencing and integration of variant reads

Circulating tumor-derived DNA (ctDNA) can be used to monitor cancer dynamics noninvasively. Detection of ctDNA can be challenging in patients with low-volume or residual disease, where plasma contains very few tumor-derived DNA fragments. We show that sensitivity for ctDNA detection in plasma can be improved by analyzing hundreds to thousands of mutations that are first identified by tumor genotyping. We describe the INtegration of VAriant Reads (INVAR) pipeline, which combines custom error-suppression methods and signal-enrichment approaches based on biological features of ctDNA. With this approach, the detection limit in each sample can be estimated independently based on the number of informative reads sequenced across multiple patient-specific loci. We applied INVAR to custom hybrid-capture sequencing data from 176 plasma samples from 105 patients with melanoma, lung, renal, glioma, and breast cancer across both early and advanced disease. By integrating signal across a median of >105 informative reads, ctDNA was routinely quantified to 1 mutant molecule per 100,000, and in some cases with high tumor mutation burden and/or plasma input material, to parts per million. This resulted in median area under the curve (AUC) values of 0.98 in advanced cancers and 0.80 in early-stage and challenging settings for ctDNA detection. We generalized this method to whole-exome and whole-genome sequencing, showing that INVAR may be applied without requiring personalized sequencing panels so long as a tumor mutation list is available. As tumor sequencing becomes increasingly performed, such methods for personalized cancer monitoring may enhance the sensitivity of cancer liquid biopsies.

Resistance of melanoma cells to anticancer treatment: a role of vascular endothelial growth factor

Melanoma is one of the most aggressive and resistant to treatment neoplasms. There are still many challenges despite many promising advances in anticancer treatment. Currently, the main problem for all types of treatment is associated with heterogeneity. Due to heterogeneity of cancer cells, "precise" targeting of a medicine against a single phenotype limits the efficacy of treatment and affects resistance to applied therapy. Therefore it is important to understand aetiology and reasons for heterogeneity in order to develop effective and long-lasting treatment. This review summarises roles of vascular endothelial growth factor (VEGF) that may stimulate growth of a melanoma tumour irrespective of its proangiogenic effects, contributing to cancer heterogeneity. VEGF triggers processes associated with extracellular matrix remodelling, cell migration, invasion, angiogenesis, inhibition of immune responses and favours phenotypic plasticity and epithelial-mesenchymal transition. Consequently, it participates in mechanisms of interactions between melanoma cancer cells and microenvironment and it can modify sensitivity to therapeutic factors.

Combining Immune Checkpoint Inhibitors with Anti-Angiogenic Agents

Immunotherapy has recently emerged as a novel strategy for treating different types of solid tumors, with promising results. However, still a large fraction of patients do not primarily respond to such approaches, and even responders sooner or later develop resistance. Moreover, immunotherapy is a promising strategy for certain malignancies but not for others, with this discrepancy having been attributed to a more immunogenic microenvironment of some tumors. As abnormal and augmented tumor vessels often occur in cancerogenesis, anti-angiogenic drugs have already demonstrated their effectiveness both in preclinical and in clinical settings. By targeting abnormal formation of tumor vessels, anti-angiogenetic agents potentially result in an enhanced infiltration of immune effector cells. Moreover, crosstalks downstream of the immune checkpoint axis and vascular endothelial growth factor receptor (VEGFR) signaling may result in synergistic effects of combined treatment in tumor cells. In this review, we will describe and discuss the biological rationale of a combined therapy, underlying the modification in tumor microenvironment as well as in tumor cells after exposure to checkpoint inhibitors and anti-angiogenic drugs. Moreover, we will highlight this strategy as a possible way for overcoming drug resistance. By first discussing potential prognostic and predictive factors for combined treatment, we will then turn to clinical settings, focusing on clinical trials where this strategy is currently being investigated.

Vessel co-option and resistance to anti-angiogenic therapy

Vessel co-option is a non-angiogenic mechanism of tumour vascularisation in which cancer cells utilise pre-existing blood vessels instead of inducing new blood vessel formation. Vessel co-option has been observed across a range of different tumour types, in both primary cancers and metastatic disease. Importantly, vessel co-option is now implicated as a major mechanism that mediates resistance to conventional anti-angiogenic drugs and this may help to explain the limited efficacy of this therapeutic approach in certain clinical settings. This includes the use of anti-angiogenic drugs to treat advanced-stage/metastatic disease, treatment in the adjuvant setting and the treatment of primary disease. In this article, we review the available evidence linking vessel co-option with resistance to anti-angiogenic therapy in numerous tumour types, including breast, colorectal, lung and pancreatic cancer, glioblastoma, melanoma, hepatocellular carcinoma, and renal cell carcinoma. The finding that vessel co-option is a significant mechanism of resistance to anti-angiogenic therapy may have important implications for the future of anti-cancer therapy, including (a) predicting response to anti-angiogenic drugs, (b) the need to develop therapies that target both angiogenesis and vessel co-option in tumours, and (c) predicting the response to other therapeutic modalities, including immunotherapy.

ctDNA detected by ddPCR reveals changes in tumour load in metastatic malignant melanoma treated with bevacizumab

Bevacizumab is included in an increasing number of clinical trials. To find biomarkers to predict and monitor treatment response, cancer and angiogenesis relevant mutations in tumour and circulating tumour DNA (ctDNA) were investigated in 26 metastatic melanoma patients treated with bevacizumab. Patients with >1% BRAF/NRAS ctDNA at treatment start had significantly decreased progression free survival (PFS) and overall survival (OS) (PFS: p = 0.019, median 54 vs 774 days, OS: p = 0.026, median 209 vs 1064 days). Patients with >1% BRAF/NRAS ctDNA during treatment showed similar results (PFS: p = 0.002, OS: p = 0.003). ≤1% BRAF/NRAS ctDNA and normal lactate dehydrogenase (LDH) levels both significantly predicted increased response to treatment, but BRAF/NRAS ctDNA was better at predicting response compared to LDH at treatment start (OR 16.94, p = 0.032 vs OR 4.57, p = 0.190), and at predicting PFS (HR 6.76, p = 0.002) and OS (HR 6.78, p = 0.002) during therapy. ctDNA BRAF p.V600D/E/K and NRAS p.G12V/p.Q61K/L/R were better biomarkers for response prediction than TERT promoter mutations (OR 1.50, p = 0.657). Next generation sequencing showed that all patients with ≥2 mutations in angiogenesis-relevant genes had progressive disease, but did not reveal other biomarkers identifying responders. To conclude, ctDNA and LDH are useful biomarkers for both monitoring and predicting response to bevacizumab.

Monoclonal Antibodies in Dermatooncology-State of the Art and Future Perspectives

Monoclonal antibodies (mAbs) targeting specific proteins are currently the most popular form of immunotherapy used in the treatment of cancer and other non-malignant diseases. Since the first approval of anti-CD20 mAb rituximab in 1997 for the treatment of B-cell malignancies, the market is continuously booming and the clinically used mAbs have undergone a remarkable evolution. Novel molecular targets are constantly emerging and the development of genetic engineering have facilitated the introduction of modified mAbs with improved safety and increased capabilities to activate the effector mechanisms of the immune system. Next to their remarkable success in hematooncology, mAbs have also an already established role in the treatment of solid malignancies. The recent development of mAbs targeting the immune checkpoints has opened new avenues for the use of this form of immunotherapy, also in the immune-rich milieu of the skin. In this review we aim at presenting a comprehensive view of mAbs' application in the modern treatment of skin cancer. We present the characteristics and efficacy of mAbs currently used in dermatooncology and summarize the recent clinical trials in the field. We discuss the side effects and strategies for their managing.

The adjuvant treatment revolution for high-risk melanoma patients

The past 5 years have witnessed the results of many practice-changing studies that have dramatically improved the landscape of adjuvant therapy in patients with resected, high-risk melanoma. After a 20-year era of adjuvant interferon, the anti-CTLA-4 and anti-PD-1 immune-checkpoint inhibitors, and MAPK-directed targeted therapy brought a revolution into the adjuvant treatment of melanoma. These results came along with the practice-changing results of two large multicenter studies showing no benefit in terms of overall survival for completion lymph node dissection after positive sentinel node biopsy. In this review, we summarized the current state of the art of the adjuvant treatment of high-risk melanoma, with a view on future perspectives.

Expression of VEGF in human conjunctival melanoma analyzed with immunohistochemistry

Purpose

The aim of this study was to examine the immunolocalization of VEGF-A and CD34, a marker of endothelial cells, in human conjunctival melanoma.

Methods

This study retrospectively analyzed primary conjunctival melanoma patients who underwent surgical resection of the tumor. All excised tissues were fixed with paraformaldehyde and embedded in paraffin, which were then submitted for immunohistochemistry with anti-VEGF and CD34 antibodies.

Results

The study sample comprised 4 female and two male melanoma patients. The age of the patients ranged from 64 to 84 (average age, 73) years. Histopathology of the surgically resected tumor tissues demonstrated accumulation of polygonal atypical malignant cells producing melanin. Cytoplasmic immunoreactivity for VEGF was clearly observed in tumor cells of all six tumors. In contrast, CD34-positive endothelial cells were less marked in the melanoma tissues than in the adjacent noncancerous subconjunctival stroma.

Conclusion

VEGF immunoreactivity was observed in conjunctival melanoma tissues, in which endothelial cells were hardly observed. These results suggest that although VEGF is expressed, conjunctival melanoma is a hypovascular tumor.