Relationship between tumor-associated immune infiltrate and p16 staining over clinicopathological features in acral lentiginous melanoma

The Effectiveness of Adjuvant PD-1 Inhibitors in Patients With Surgically Resected Stage III/IV Acral Melanoma

Our aim was to assess the efficacy of adjuvant programmed cell death protein-1 (PD-1) inhibitors and compare the other adjuvant treatments in patients with surgically resected stage III or IV acral melanoma. This study is a multicenter, retrospective analysis. We included 114 patients with stage III or IV acral malignant melanoma who underwent surgery within the past 10 years. We analyzed the effect of adjuvant programmed cell death protein-1 inhibitors on disease-free survival (DFS). The mean follow-up was 40 months, during which 69 (59.5%) patients experienced recurrence. Among the participants, 64 (56.1%) received systemic adjuvant therapy. Specifically, 48.4% received anti-PD-1 therapy, 29.7% received interferon, 14.1% received tezozolomide, and 7.8% received B-Raf proto-oncogene/mitogen-activated protein kinase inhibitors. Patients who received adjuvant therapy had a median DFS of 24 (10.9-37.2) months, whereas those who did not receive adjuvant therapy had a median DFS of 15 (9.8-20.2) months. Multivariate analysis for DFS revealed that the receipt of adjuvant therapy and lymph node metastasis stage were independent significant parameters ( P = 0.021, P = 0.018, respectively). No statistically significant difference was observed for DFS between programmed cell death protein-1 inhibitor treatment and other adjuvant treatments. Regarding overall survival (OS), patients who received adjuvant treatment had a median OS of 71 (30.4-111.7) months, whereas those who did not receive adjuvant treatment had a median OS of 38 (16.7-59.3; P = 0.023) months. In addition, there were no significant differences in OS observed between various adjuvant treatment agents ( P = 0.122). In our study, we have shown that adjuvant therapy had a positive effect on both DFS and OS in patients with stages III-IV acral melanoma who underwent curative intent surgery. Notably, we found no significant differences between anti-PD-1 therapy and other adjuvant therapies.

CD8-Lymphocytic Phenotype Significance in Primary Multiple and Familial Melanoma with Various CDKN2A Mutational Status

Background and Objectives: In the realm of the rising incidence of cutaneous and mucous melanoma, CDKN2A mutations characterize familial and multiple primary melanoma cases. The involvement of tumor-infiltrating lymphocytes (TILs) is interconnected with survival rates, but may extend even further. The aim of this study is to verify the accuracy of the classical "naked eye" count of CD8-positive T cells comprised within the tumoral population and peritumoral infiltrate versus that obtained via a special software run by the aid of artificial intelligence (AI), used to determine the percentage of CD8-positive TILs. Materials and Methods: The present retrospective cross-sectional study conducted over a period of 5 years (2018-2022) focused on patients diagnosed with mucous and/or cutaneous melanoma, with a positive family history for melanoma, or personal antecedents of primary malignant melanocytic lesions. The 23 selected cases were diagnosed histopathologically, tested for CDKN2A mutations through fluorescent hybridization in situ, and CD8 immunohistochemistry was performed. The included slides were evaluated both manually (naked-eye examination) and automatically (via QuPath platform) for quantifying the CD8-positive TILs. Results: The number of CD8-positive TILs in melanoma samples has been more accurately identified through the use of an AI-mediated software as compared to the human-eye evaluation performed by experimental pathologists. A higher percentage of CD8-positive intratumoral lymphocytes versus stromal lymphocytes was positively associated with more numerous metastatic sites. Conclusions: The CD8 lymphocytic phenotype harbors major significance in the context of familial and multiple primary melanoma and may comprise a cost-effective investigation meant to help in the establishment of melanoma prognosis and response to immunotherapy.

Cutaneous immune-related adverse events from immune checkpoint inhibitor therapy: Moving beyond "maculopapular rash"

Uncoupling toxicity from therapeutic effect lies at the foundation of the current state of the field of cutaneous immune-related adverse events to immune checkpoint inhibitor therapy. This will be achieved through understanding the drivers of toxicity, tumor response, and resistance via large, well-powered population-level studies, institutional cohort data, and cellular-level data. Increasing diagnostic specificity through the application of consensus disease definitions has the power to improve clinical care and each approach to research. Cutaneous immune-related adverse events are associated with increased survival, and their treatment must invoke the maintenance of a delicate balance between immunosuppression, anti-tumor effect of immune checkpoint inhibitor therapy, and quality of life. The multidisciplinary care of cancer patients with adverse events is critical to optimizing clinical and translational research outcomes and, as such, dermatologists are vital to moving the study of cutaneous adverse events forward.

Apatinib combined with camrelizumab in advanced acral melanoma patients: An open-label, single-arm phase 2 trial

BACKGROUND

At present, immune monotherapy and combination therapy has not shown satisfactory effects on acral melanoma, and still no standard treatment is available for advanced acral melanoma. Here, a phase II trial was performed to explore the safety and efficacy of apatinib combined with camrelizumab in advanced acral melanoma patients as first-line therapy (NCT03955354).

METHODS

Patients with pathologically confirmed, locally unresectable or metastatic treatment native acral melanoma received 250 mg apatinib once daily and camrelizumab 200 mg once every two weeks intravenously every 28-day cycle. The primary end-point was objective response rate and the secondary end-points were disease control rate, overall survival, progression-free survival and safety.

RESULTS

Thirty patients were recruited between January 2015 and January 2022. Among them, 21 (70.0%) had stage IV, and a median tumour burden was 50 mm (range: 11-187). Objective response rate was 24.1%, and 7 of 29 patients had an anti-tumour response, including partial response (n = 5) and complete response (n = 2). Disease control rate was 82.8%, median progression-free survival was 7.39 months (confidence interval: 3.65-9.92), and median overall survival was 13.4 months (confidence interval: 1.9-25.0). Grade 3-4 treatment-related toxicity (grade 3 50.5%; grade 4 3.3%) included transaminase elevations, proteinuria, leukocytopenia, vomiting, diarrhea and drug-induced liver injury. No treatment-related mortality occurred. The mutations of TTN, MUC16, VPS13D, ALPK2 and SCUBE1 showed significant alterations with survival outcome.

CONCLUSIONS

Apatinib combined with camrelizumab showed manageable safety profile and reasonable anti-tumour activity in advanced acral melanoma patients as first-line therapy.

Advanced Acral Melanoma Therapies: Current Status and Future Directions

Melanoma is one of the deadliest malignancies. Its incidence has been significantly increasing in most countries in recent decades. Acral melanoma (AM), a peculiar subgroup of melanoma occurring on the palms, soles, and nails, is the main subtype of melanoma in people of color and is extremely rare in Caucasians. Although great progress has been made in melanoma treatment in recent years, patients with AM have shown limited benefit from current therapies and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in this high-risk melanoma subtype represents one of the greatest challenges in the field. The frequency of BRAF mutations in AM is much lower than that in cutaneous melanoma, which prevents most AM patients from receiving treatment with BRAF inhibitors. However, AM has more frequent mutations such as KIT and CDK4/6, so targeted therapy may still improve the survival of some AM patients in the future. AM may be less susceptible to immune checkpoint inhibitors because of the poor immunogenicity. Therefore, how to enhance the immune response to the tumor cells may be the key to the application of immune checkpoint inhibitors in advanced AM. Anti-angiogenic drugs, albumin paclitaxel, or interferons are thought to enhance the effectiveness of immune checkpoint inhibitors. Combination therapies based on the backbone of PD-1 are more likely to provide greater clinical benefits. Understanding the molecular landscapes and immune microenvironment of AM will help optimize our combinatory strategies.

Clinical features, molecular pathology, and immune microenvironmental characteristics of acral melanoma

Acral melanoma (AM) has unique biology as an aggressive subtype of melanoma. It is a common subtype of melanoma in races with darker skin tones usually diagnosed at a later stage, thereby presenting a worse prognosis compared to cutaneous melanoma. The pathogenesis of acral melanoma differs from cutaneous melanoma, and trauma promotes its development. Compared to cutaneous melanomas, acral melanomas have a significantly lighter mutational burden with more copy number variants. Most acral melanomas are classified as triple wild-type. In contrast to cutaneous melanomas, acral melanomas have a suppressive immune microenvironment. Herein, we reviewed the clinical features, genetic variants, and immune microenvironmental characteristics of limbic melanomas to summarise their unique features.

Systematic review and meta-analysis of genomic alterations in acral melanoma

Acral melanoma (AM) tumors arise on the palms, soles, fingers, toes, and nailbeds. A comprehensive systematic meta-analysis of AM genomic aberrations has not been conducted to date. A literature review was carried out to identify studies sequencing AM. Whole-genome/exome data from 181 samples were identified. Targeted panel sequencing data from MSK-IMPACT were included as a validation cohort (n = 92), and studies using targeted hot spot sequencing were also collated for BRAF (n = 26 studies), NRAS (n = 21), and KIT (n = 32). Statistical analysis indicated BRAF, NRAS, PTEN, TYRP1, and KIT as significantly mutated genes. Frequent copy-number aberrations were also found for important cancer genes, such as CDKN2A, KIT, MDM2, CCND1, CDK4, and PAK1, among others. Mapping genomic alterations within the context of the hallmarks of cancer identified four components frequently altered, including (i) sustained proliferative signaling and (ii) evading growth suppression, (iii) genome instability and mutation, and (iv) enabling replicative immortality. This analysis provides the largest analysis of genomic aberrations in AM in the literature to date and highlights pathways that may be therapeutically targetable.

Neural stem cells secreting bispecific T cell engager to induce selective antiglioma activity

Glioblastoma (GBM) is the most lethal primary brain tumor in adults. No treatment provides durable relief for the vast majority of GBM patients. In this study, we've tested a bispecific antibody comprised of single-chain variable fragments (scFvs) against T cell CD3ε and GBM cell interleukin 13 receptor alpha 2 (IL13Rα2). We demonstrate that this bispecific T cell engager (BiTE) (BiTE^LLON) engages peripheral and tumor-infiltrating lymphocytes harvested from patients' tumors and, in so doing, exerts anti-GBM activity ex vivo. The interaction of BiTE^LLON with T cells and IL13Rα2-expressing GBM cells stimulates T cell proliferation and the production of proinflammatory cytokines interferon γ (IFNγ) and tumor necrosis factor α (TNFα). We have modified neural stem cells (NSCs) to produce and secrete the BiTE^LLON (NSC^LLON). When injected intracranially in mice with a brain tumor, NSC^LLON show tropism for tumor, secrete BiTE^LLON, and remain viable for over 7 d. When injected directly into the tumor, NSC^LLON provide a significant survival benefit to mice bearing various IL13Rα2⁺ GBMs. Our results support further investigation and development of this therapeutic for clinical translation.

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.

Melanoma-specific expression of the tumor suppressor proteins p16 and PTEN is a favorable prognostic factor in established melanoma brain metastases

PTEN and p16 frequently undergo (epi)genetic aberrations in melanoma resulting in decreased, or absent, protein levels. We investigated the prognostic significance of these tumor suppressor genes in melanoma brain metastases (MBMs). Immunohistochemical analysis was performed on archived tissue sections from craniotomies. Expression of PTEN and p16 was semiquantitatively scored (0-3 scale) in melanoma cells, glia, TILs, and endothelial cells of tumor-associated vessels and was compared among the different brain tumor cell compartments. Overall survival (OS) analysis was performed according to PTEN and p16 protein expression in melanoma cells. 58 patients (median age 56, 37 male) underwent craniotomy for MBMs before February 2014. The OS of patients with decreased, or absent, protein expression (0, 1+) of PTEN and p16 in melanoma cells was significantly shorter compared to that of patients with high (2+, 3+) expression (median OS 2.40 vs. 10.75 months and 4.1 vs. 8.1 months, respectively; Gehan-Breslow-Wilcoxon test P = 0.026 and P = 0.037, respectively). PTEN and p16 protein expression were significantly lower in TILs compared to melanoma cells (Mann-Whitney test P = 0.023 and P < 0.0001, respectively). Low/absent protein expression of PTEN/p16 is an adverse prognostic factor in MBMs. Surprisingly, expression of both PTEN and p16 proteins was significantly lower in TILs compared to melanoma cells. Proliferating (p16 absent/low) TILs within the brain with or without an active PI3K-Akt pathway (PTEN absent/low) may represent a favorable host response in MBMs. Thus, treatment of patients with MBMs with CDK4/6 or PI3K pathway inhibitors may result in an unfavorable, bystander, off-target effect on host immune response.

Targeting the IL-2 inducible kinase in melanoma; a phase 2 study of ibrutinib in systemic treatment-refractory distant metastatic cutaneous melanoma: preclinical rationale, biology, and clinical activity (NCI9922)

BACKGROUND

IL-2 inducible kinase (ITK) is highly expressed in metastatic melanomas and its inhibition suppresses melanoma cell proliferation. We hypothesize that ibrutinib has a direct antitumor effect in melanoma cell lines and that treatment of metastatic melanomas with ibrutinib induces antitumor responses.

METHODS

We assessed the ibrutinib effect on melanoma cell proliferation, apoptosis, and motility. Patients with metastatic melanoma refractory to PD-1 and MAPK inhibitors (if BRAFV600-mutant) were treated with ibrutinib, 840 mg PO QD, as part of a phase II clinical trial (clinicaltrials.gov NCT02581930).

RESULTS

Melanoma cell lines frequently express ITK, YES1, and EGFR. Ibrutinib suppressed cell motility and proliferation in most cell lines. Eighteen patients (13 male; median age 63.5 years, range 37-82; 12 with ipilimumab resistance) were enrolled. The most frequent side effects were fatigue (61%), anorexia (50%), hyponatremia (28%), nausea, and vomiting (22% each). No antitumor responses were seen. At a median follow-up of 6 months (0.3-35.8 months), the median progression-free survival was 1.3 months (range 0.2-5.5 months). Fifteen patients were discontinued from the study due to progression, and 14 patients had died from metastatic melanoma. All archived tumors expressed ITK, 41% had no expression of p16 and PTEN, and 61% had absent tumor-infiltrating lymphocytes (TILs). Ibrutinib significantly suppressed proliferating (Ki67+) CD19+ peripheral blood mononuclear cells and had no significant effect on other lymphocyte subsets.

CONCLUSION

Ibrutinib did not induce any meaningful clinical benefit. ITK expression may not be clinically relevant. Treatment-refractory metastatic melanomas have other fundamental defects (i.e. absent PTEN and p16 expression, absent TILs) that may contribute to an adverse prognosis.

Clinical Significance of Tumor Microenvironment in Acral Melanoma: A Large Single-Institution Study of Caucasians

Background: The presence of tumor-infiltrating lymphocytes (TILs) in many studies is associated with a better prognosis in melanoma patients. Programmed death-ligand 1 (PD-L1) expression has a significant value in predicting several cancers, but its role in melanoma remains ambiguous. The study aims to report a comprehensive analysis of TILs characteristics and their impact on survival in primary acral melanoma (AM). Methods: Clinical and pathological features and survival outcomes were investigated in 70 patients with AM. Immunohistochemical quantitative analysis of TILs, including expression of CD4, CD8, FOXP3, PD-1, and PD-L1, on melanoma cells was performed. Results: Kaplan-Meier analysis showed significant differences in overall survival (OS) for CD4+ (p = 0.021), CD8+ (p = 0.037), FOXP3+ (p = 0.007), and TILs density (p = 0.043). In univariate analysis of immunohistochemical features, FOXP3, CD4, CD8, PD-1, and Melanoma Institute of Australia (MIA) grading TILs (grade, density, and distribution) were correlated with survival. The higher density of FOXP3-positive cells was an independent factor associated with better survival. Conclusions: High TILs content (classed as brisk Clark scale and marked/diffuse TILs MIA grade) regardless of its immunophenotype was associated with better survival outcomes in AM. PD-L1 expression on tumor cells did not influence OS and was independent of clinical and pathological characteristics. We demonstrated that TILs are significant biomarkers in sentinel lymph node status prediction.

The relationships between PD-L1 expression, CD8+ TILs and clinico-histomorphological parameters in malignant melanomas

INTRODUCTION

Malignant melanomas (MM) are often connected with the expression of PD-L1 protein and the presence of tumor-infiltrating lymphocytes (TILs), however, their impact on prognosis remains controversial. Due to their supposed clinical significance and lack of convincing data, we decided to establish the relationships between CD8 + TIL count, PD-L1 level and certain clinical and histopathological parameters in patients with malignant melanoma, especially those associated with unfavorable prognosis.

MATERIALS AND METHODS

We performed immunohistochemistry for PD-L1 and CD8 on 56 formalin-fixed paraffin-embedded specimens from patients with cutaneous and metastatic malignant melanomas. PD-L1 expression levels were determined by immunohistochemistry (clone 28-8) and subsequently the tumor proportion scores (TPS) were evaluated. CD8 + TIL expressions were classified as either grade 0, 1+, 2+ or 3+, based on the density and distribution of the infiltrating lymphocytes.

RESULTS

The PD-L1 expression was detected in 20 out of 56 cases (35,71 %). The expression of PD-L1 on tumor cells was significantly increased with higher TILs infiltration in the tumor microenvironment (p = 0,038). Lower TIL score corresponds with poor prognostic clinicopathological parameters such as higher number of mitotic figures (p = 0,005), Clark's level (p = 0,007) and Breslow's depth (p = 0,010).

CONCLUSIONS

Our results suggest a favorable prognostic value for CD8 + TIL infiltration. Moreover, TIL density was strongly correlated and geographically associated to PD-L1 expression. This analysis provides more insight into the role of TIL count and PD-L1 level in MM and their relationship with each other and association with other prognostic indicators.

Acral lentiginous melanoma: Basic facts, biological characteristics and research perspectives of an understudied disease

Acral lentiginous melanoma is a histological subtype of cutaneous melanoma that occurs in the glabrous skin of the palms, soles and the nail unit. Although in some countries, particularly in Latin America, Africa and Asia, it represents the most frequently diagnosed subtype of the disease, it only represents a small proportion of melanoma cases in European‐descent populations, which is partially why it has not been studied to the same extent as other forms of melanoma. As a result, its unique genomic drivers remain comparatively poorly explored, as well as its causes, with current evidence supporting a UV‐independent path to tumorigenesis. In this review, we discuss current knowledge of the aetiology and diagnostic criteria of acral lentiginous melanoma, as well as its epidemiological and histopathological characteristics. We also describe what is known about the genomic landscape of this disease and review the available biological models to explore potential therapeutic targets.

Immune System Evasion as Hallmark of Melanoma Progression: The Role of Dendritic Cells

Melanoma is an immunogenic tumor whose relationship with immune cells resident in the microenvironment significantly influences cancer cell proliferation, progression, and metastasis. During melanomagenesis, both immune and melanoma cells undergo the immunoediting process that includes interconnected phases as elimination, equilibrium, and escape or immune evasion. In this context, dendritic cells (DCs) are active players that indirectly counteract the proliferation of melanoma cells. Moreover, DC maturation, migration, and cross-priming as well as their functional interplay with cytotoxic T-cells through ligands of immune checkpoint receptors result impaired. A number of signals propagated by highly proliferating melanoma cells and accessory cells as T-cells, natural killer cells (NKs), tumor-associated macrophages (TAMs), T-regulatory cells (T-regs), myeloid-derived suppressor cells (MDSCs), and endothelial cells participate to create an immunosuppressive milieu that results engulfed of tolerogenic factors and interleukins (IL) as IL-6 and IL-10. To underline the role of the immune infiltrate in blocking the melanoma progression, it has been described that the composition, density, and distribution of cytotoxic T-cells in the surrounding stroma is predictive of responsiveness to immunotherapy. Here, we review the major mechanisms implicated in melanoma progression, focusing on the role of DCs.

Translational pathology, genomics and the development of systemic therapies for acral melanoma

Acral melanomas arise on the non-hair bearing skin of the palms, soles and in the nail beds. These rare tumors comprise 2-3 % of all melanomas, are not linked to UV-exposure, and represent the most frequent subtype of melanomas in patients of Asian, African and Hispanic origin. Although recent work has revealed candidate molecular events that underlie acral melanoma development, this knowledge is not yet been translated into efficacious local, regional, or systemic therapies. In the current review, we describe the clinical characteristics of acral melanoma and outline the genetic basis of acral melanoma development. Further discussion is given to the current status of systemic therapy for acral melanoma with a focus on ongoing developments in both immunotherapy and targeted therapy for the treatment of advanced disease.

Clinical relevance and significance of programmed death-ligand 1 expression, tumor-infiltrating lymphocytes, and p16 status in sinonasal squamous cell carcinoma

Purpose: Immunotherapy may be a potential alternative for patients with sinonasal squamous cell carcinoma (SNSCC). Data regarding potential immunotherapy targets, such as programmed death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs), in SNSCC are limited. In this study, we assessed the prevalence and prognostic value of PD-L1 expression and TILs in p16-negative and p16-positive SNSCC. Patients and methods: Tissues from 96 patients with SNSCC were stained using immunohistochemistry against PD-L1, CD8, and Foxp3 to assess the immune environment. The correlations between PD-L1 expression, TILs, and p16 status were analyzed. Additionally, PD-L1, CD8, and Foxp3 expressions, as well as p16 status, were analyzed in relation to patient clinicopathological variables and prognosis. Results: Twenty-nine (30.2%) patients with SNSCC showed PD-L1 expression in >5% of tumor cells. PD-L1 expression was significantly correlated with poor differentiation and a high level of TILs. PD-L1 expression and the CD8+ and Foxp3+ T-cell infiltrates in p16-negative patients (n=78, 81.2%) and p16-positive patients (n=18, 18.8%) were not significantly different. PD-L1 expression and p16 status were not associated with overall survival (OS) and disease-free survival (DFS). Patients with high CD8+ or Foxp3+ cell infiltration had better clinical outcomes. A multivariate analysis confirmed that CD8 TILs were a significant independent and favorable prognostic factor for OS (p=0.023) and DFS (p=0.008). Conclusion: TILs can play a prognostic role in SNSCC. We did not find differences in immune marker expression between p16-positive and p16-negative SNSCC tissues. The high correlation between PD-L1 expression and TILs indicates that the PD-1/PD-L1 pathway is a promising immunotherapeutic target for SNSCC.