How we treat locoregional melanoma

The combination of single-cell and RNA sequencing analysis decodes the melanoma tumor microenvironment and identifies novel T cell-associated signature genes

Skin cutaneous melanoma (SKCM), a malignant melanocyte-derived skin cancer, potentially leads to fatal outcomes without effective treatment. The variability in immunotherapy responses among melanoma patients is significantly influenced by the intricate immune microenvironment, particularly due to the status of tumor T cells, encompassing their activity, exhaustion levels, and antigen recognition capabilities. This study utilized single-cell RNA sequencing (scRNA-seq) to analyze 34 melanoma samples from two public datasets (GSE215120 and GSE115978). Herein, we extracted 706 marker genes associated with immune checkpoint (ICP) therapy from these T cells, 509 markers of T cells from 11 melanoma tissues, and eventually identified 33 candidate genes. These genes underwent LASSO and COX regression analyses to identify the signature genes. Of the initial 33 candidate genes, we successfully isolated six distinct T cell-associated immunotherapy-related genes (IRTGs). Additionally, the computation of each patient risk score proved beneficial in evaluating the immune cell infiltration level and functions as an independent prognostic factor for melanoma patient survival. The risk score results revealed promising predictive outcomes in determining the response of melanoma patients to immunotherapy. Notably, our study is the first to reveal the potential correlation between signature gene PEB4B and the immune microenvironment in melaoma, which was explored with multiple immunofluorescence (IF) and Immune Infiltration Assessment. In a conclusion, our findings demonstrate the potential utility of a risk score dependent on signature genes as a predictive tool for assessing the prognosis and response to immunotherapeutic interventions in melanoma patients.

The role of micrometastasis in high-risk skin cancers

The propensity to metastasize is the most important prognostic indicator for solid cancers. New insights into the mechanisms of early carcinogenesis have revealed micrometastases are generated far earlier than previously thought. Evidence supports a synergistic relationship between vascular and lymphatic seeding which can occur before there is clinical evidence of a primary tumour. Early vascular seeding prepares distal sites for colonisation while regional lymphatics are co-opted to promote facilitative cancer cell mutations. In response, the host mounts a global inflammatory and immunomodulatory response towards these cells supporting the concept that cancer is a systemic disease. Cancer staging systems should be refined to better reflect cancer cell loads in various tissue compartments while clinical perspectives should be broadened to encompass this view when approaching high-risk cancers. Measured adjunctive therapies implemented earlier for low-volume, in-transit cancer offers the prospect of preventing advanced disease and the need for heroic therapeutic interventions. This review seeks to re-appraise how we view the metastatic process for solid cancers. It will explore in-transit metastasis in the context of high-risk skin cancer and how it dictates disease progression. It will also discuss how these implications will influence our current staging systems and its consequences on management.

Not Waiting to Progress; How the COVID-19 Pandemic Nudged Neoadjuvant Therapy for Stage III Locally Advanced Melanoma Patients

Background: Early-phase neoadjuvant trials have demonstrated promising results in the utility of upfront immunotherapy in locally advanced stage III melanoma and unresected nodal disease. Secondary to these results and the COVID-19 pandemic, this patient population, traditionally managed through surgical resection and adjuvant immunotherapy, received a novel treatment strategy of neoadjuvant therapy (NAT). Methods: Patients with node-positive disease, who faced surgical delays secondary to COVID-19, were treated with NAT, followed by surgery. Demographic, tumour, treatment and response data were collected through a retrospective chart review. Biopsy specimens were analysed prior to the initiation of NAT, and therapy response was analysed following surgical resection. NAT tolerability was recorded. Results: Six patients were included in this case series; four were treated with nivolumab alone, one with ipilimumab and nivolumab and one with dabrafenib and trametinib. Twenty-two incidents of adverse events were reported, with the majority (90.9%) being classified as grade one or two. All patients underwent surgical resection: three out of six patients following two NAT cycles, two following three cycles and one following six cycles. Surgically resected samples were histopathologically evaluated for the presence of disease. Five out of six patients (83%) had ≤1 positive lymph node. One patient showed extracapsular extension. Four patients demonstrated complete pathological response; two had persisting viable tumour cells. Conclusions: In this case series, we outlined how in response to surgical delays secondary to the COVID-19 pandemic, NAT was successfully applied to achieve promising treatment response in patients with locally advanced stage III melanoma.

Real-world clinical outcome and safety of adjuvant therapy in stage III melanoma patients: Data from two Academic Italian Institutions

Adjuvant immunotherapy (IO) and targeted therapy (TT) have improved relapse-free survival (RFS) in patients with stage III melanoma, although about 25% of them relapse within a year. However, real-world data on treatment efficacy and safety as well as management of treatment recurrences are still limited. We retrospectively analyzed 113 patients with stage III melanoma who received at least one cycle of anti-PD-1 (nivolumab or pembrolizumab) or dabrafenib + trametinib as adjuvant therapy. Most of patients included into the analyses harbor BRAV600E mutation (66.4%) and had a stage IIIC melanoma (63.7%). Immunotherapy was administered in 48.7% of patients, whereas targeted therapy in 51.3% At data cut-off, median RFS was not reached with 12- and 24-months RFS of 81% and 64%, respectively. No new adverse events were registered. Thirty patients (26.5%) relapsed, mainly at distant sites. Patient treated with IO recurred mostly during adjuvant treatment (ON-treatment) while patients treated with TT relapsed at the end of treatment (OFF-treatment). At relapse, surgery, radiotherapy and systemic therapy were used alone or in combination. Among patients who started a first-line therapy, an excellent response switching to a different treatment was observed. Real-world outcomes and safety of adjuvant treatment for resected stage III melanoma appear comparable to clinical trials data. Moreover, management of recurrences depends on type of relapse (loco-regional vs distant) and timing (during vs OFF treatment). Furthermore, patients who relapse after adjuvant TT respond well to subsequent anti-PD1 based therapy.

Clinical Utility of Liquid Biopsy to Detect BRAF and NRAS Mutations in Stage III/IV Melanoma Patients by Using Real-Time PCR

Simple Summary

Liquid biopsy is an increasingly used tool for melanoma diagnosis and molecular characterization, but also for monitoring of response to anticancer drugs. The aim of our work is to assess the clinical utility of a real-time quantitative PCR (qPCR)-based platform with a very short turnaround time and identify the best setting for clinical investigation. We investigated the concordance of this technique with tissue analysis in stage III–IV melanoma patients; moreover, we correlated results to clinicopathologic characteristics and outcomes. We found a higher tissue–plasma concordance in melanoma patients with high burden of disease (sum of diameters ≥30 mm, ≥2 metastatic sites, elevated LDH levels), constituting a clinical subgroup worthy of future prospective evaluation; however, the low sensitivity of this technique seems to be not sufficient for predicting relapses in radically resected patients.

Abstract

Background: Liquid biopsy is a potentially useful tool for melanoma patients, also for detecting BRAS/NRAS mutations, even if the tissue analysis remains the current standard. Methods: In this work, we tested ctDNA on plasma samples from 56 BRAF-V600/NRAS mutant stage III/IV melanoma patients using a real-time quantitative PCR (qPCR)-based platform. The study population was divided into two cohorts: the first including 26 patients who had undergone radical resection (resected cohort) and the second including 30 patients who had unresected measurable disease (advanced cohort). Moreover, for 10 patients in the advanced cohort, ctDNA assessment was repeated at specified timepoints after baseline testing. Data were analyzed and correlated to the clinicopathologic characteristics and outcomes. Results: In the baseline cohort, a higher tissue–plasma concordance was seen in patients with high burden of disease (sum of diameters ≥30 mm, ≥2 metastatic sites, elevated LDH levels); furthermore, monitoring of these patients through ctDNA analysis was informative for therapeutic responses. On the other hand, the low sensitivity of this technique did not allow for clinically valuable prediction of relapses in radically resected stage III/IV patients. Conclusions: Overall, our data suggest that qPCR-based ctDNA analysis could be informative in a subset of locally advanced and metastatic melanoma patients with specific clinical–radiological characteristics, supporting further investigations in this setting.

Hepatocellular Carcinoma Immunotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and the third leading cause of cancer-related death worldwide. Single-agent anti-PD-1 immune checkpoint inhibitors (ICIs) demonstrated promising efficacy in early-phase trials, a finding that was not confirmed in phase III studies. The combination of atezolizumab (an anti-PD-L1 ICI) with bevacizumab (an anti-VEGF antibody) was approved as first-line therapy in 2020, however, with significant improvement in response rate, progression-free survival, and overall survival in comparison with the previous standard of care, sorafenib. Numerous ongoing clinical trials are assessing ICIs in combination with each other or with targeted agents, and also in earlier stages with local therapies. This review summarizes the latest concepts in the use of ICIs for the management of HCC. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Combination of Pembrolizumab with Electrochemotherapy in Cutaneous Metastases from Melanoma: A Comparative Retrospective Study from the InspECT and Slovenian Cancer Registry

Simple Summary

Electrochemotherapy (ECT) combines a cytotoxic agent with locally applied electric pulses to enhance its antitumor effect. Over the last 15 years, ECT has been safely applied to patients with skin metastases in combination with other oncologic treatments and, more recently, with systemic immunotherapy. In this study, we aimed to investigate the effectiveness of ECT in combination with pembrolizumab. We compared patient outcomes after the following treatments: (a) pembrolizumab, (b) pembrolizumab and ECT, and (c) ECT alone. The combined application of pembrolizumab and ECT was safe and more efficacious in preventing further growth of cutaneous metastases than pembrolizumab alone. The patients treated with pembrolizumab and ECT experienced lower disease progression rates and longer survival than those who received pembrolizumab. ECT may boost the effect of pembrolizumab by acting as an in situ vaccination against cancer cells. Further studies are required to confirm these findings.

Abstract

Electrochemotherapy (ECT) is an effective locoregional therapy for cutaneous melanoma metastases and has been safely combined with immune checkpoint inhibitors in preliminary experiences. Since ECT is known to induce immunogenic cell death, its combination with immune checkpoint inhibitors might be beneficial. In this study, we aimed to investigate the effectiveness of ECT on cutaneous melanoma metastases in combination with pembrolizumab. We undertook a retrospective matched cohort analysis of stage IIIC–IV melanoma patients, included in the International Network for sharing practices of ECT (InspECT) and the Slovenian Cancer Registry. We compared the outcome of patients who received the following treatments: (a) pembrolizumab alone, (b) pembrolizumab plus ECT, and (c) ECT. The groups were matched for age, sex, performance status, and size of skin metastases. The local objective response rate (ORR) was higher in the pembrolizumab-ECT group than in the pembrolizumab group (78% and 39%, p < 0.001). The 1 year local progression-free survival (LPFS) rates were 86% and 51% (p < 0.001), and the 1 year systemic PFS rates were 64% and 39%, respectively (p = 0.034). The 1 year overall survival (OS) rates were 88% and 64%, respectively (p = 0.006). Our results suggest that skin-directed therapy with ECT improves superficial tumor control in melanoma patients treated with pembrolizumab. Interestingly, we observed longer PFS and OS in the pembrolizumab-ECT group than in the pembrolizumab group. These findings warrant prospective confirmation.