Prognosis Of Metastatic Melanoma Research Articles

PTERT C250T mutation: A potential biomarker of poor prognosis in metastatic melanoma

Melanoma is the most aggressive form of skin cancer and the leading cause of death from cutaneous tumors. Several studies have associated alterations in the TERT promoter region (pTERT) with gene overexpression, aggressiveness and poor prognosis of the disease. The aim of this study was to clarify the role of pTERT molecular status in paired samples of primary melanoma and metastasis using tissue and plasma to establish a correlation with disease progression and survival.A total of 88 FFPE tissue samples from 53 patients with advanced melanoma were analyzed. Of these, 35 had paired samples. We also examined cfDNA samples from plasma of 25 patients. We detected a good correlation between primary tumors and metastases in pTERT mutation and methylation status. We were also able to identify pTERT mutations in plasma samples that correlated with mutational status in tissue samples. Interestingly, the C250T mutation was associated with worse survival and higher TERT mRNA expression, compared to the other most common mutation: C228T. In addition, hyper-methylation of the promoter region seems to be related to the progression of pTERT wild type (WT) patients. These results suggest that TERT gene alterations plays an important role during tumor progression, with the detection of the C250T mutation in tissue and plasma as a potential biomarker of poor prognosis in patients with advanced melanoma.

CTLA4 mRNA is downregulated by miR-155 in regulatory T cells, and reduced blood CTLA4 levels are associated with poor prognosis in metastatic melanoma patients.

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an immune checkpoint expressed in regulatory T (Treg) cells and activated T lymphocytes. Despite its potential as a treatment strategy for melanoma, CTLA-4 inhibition has limited efficacy. Using data from The Cancer Genome Atlas (TCGA) melanoma database and another dataset, we found that decreased CTLA4 mRNA was associated with a poorer prognosis in metastatic melanoma. To investigate further, we measured blood CTLA4 mRNA in 273 whole-blood samples from an Australian cohort and found that it was lower in metastatic melanoma than in healthy controls and associated with worse patient survival. We confirmed these findings using Cox proportional hazards model analysis and another cohort from the US. Fractionated blood analysis revealed that Treg cells were responsible for the downregulated CTLA4 in metastatic melanoma patients, which was confirmed by further analysis of published data showing downregulated CTLA-4 surface protein expression in Treg cells of metastatic melanoma compared to healthy donors. Mechanistically, we found that secretomes from human metastatic melanoma cells downregulate CTLA4 mRNA at the post-transcriptional level through miR-155 while upregulating FOXP3 expression in human Treg cells. Functionally, we demonstrated that CTLA4 expression inhibits the proliferation and suppressive function of human Treg cells. Finally, miR-155 was found to be upregulated in Treg cells from metastatic melanoma patients compared to healthy donors. Our study provides new insights into the underlying mechanisms of reduced CTLA4 expression observed in melanoma patients, demonstrating that post-transcriptional silencing of CTLA4 by miRNA-155 in Treg cells may play a critical role. Since CTLA-4 expression is downregulated in non-responder melanoma patients to anti-PD-1 immunotherapy, targeting miRNA-155 or other factors involved in regulating CTLA4 expression in Treg cells without affecting T cells could be a potential strategy to improve the efficacy of immunotherapy in melanoma. Further research is needed to understand the molecular mechanisms regulating CTLA4 expression in Treg cells and identify potential therapeutic targets for enhancing immune-based therapies.

YTHDF3 promotes melanoma metastasis by reading N6‐methyladenosine

YTHDF3 promotes melanoma metastasis by reading N⁶‐methyladenosine

Characteristics of Patients Who Survived More than 5 Years after Diagnosis of Melanoma Brain Metastases

<h3>Purpose/Objective(s)</h3> Patients with melanoma brain metastases (mBM) have historically demonstrated poor overall survival (OS). However, the prognosis of metastatic melanoma has improved dramatically in the era of immunotherapy. At our institution, we have a substantial cohort of patients who received intracranial RT and survived more than five years after diagnosis of mBM. We performed a descriptive study to characterize this cohort. <h3>Materials/Methods</h3> Patients who received intracranial RT for mBM at our institution were identified retrospectively. Those with OS greater than five years after diagnosis of mBM were included. Patient, disease, and treatment characteristics were collected. Kaplan-Meier analysis was used to estimate OS and intracranial progression-free survival (iPFS). Patients with histologically proven radiation necrosis (RN) were identified. <h3>Results</h3> Forty-five patients with 127 mBM at diagnosis received RT between 2006 and 2017 and survived more than 5 years. The median age at mBM diagnosis was 59 years (range, 32 to 73), and 69% were male. The primary tumor was cutaneous in 76% and unknown in 24%. BRAF V600 mutations were identified in 51% of patients. The median number of mBM at diagnosis was 2 (range, 1 to 14), and the median largest dimension was 2.3 cm (range, 0.3 to 5.4). Thirty-one mBM (24%) in 27 patients (60%) were resected prior to RT. Forty patients (89%) had stereotactic radiosurgery and 5 patients (11%) had whole brain RT as their initial RT modality. At mBM diagnosis, 31% had no evidence of disease (NED) extracranially. Most patients (91%) received immunotherapy. This was delivered concurrently with RT (47%), prior to RT (16%), or after RT (33%). At a median of 85 months of follow-up, 9 patients (20%) were deceased, including only 2 with clear evidence of intracranial progression, and 31 (69%) were alive and NED. Median OS was 156 months. Intracranial progression was observed in 19 patients (42%) at a median of 134 months. Histologically proven RN was identified in 11 patients (24%). <h3>Conclusion</h3> To our knowledge, these 45 patients constitute the largest report of mBM patients with OS exceeding 5 years. Most of this cohort was alive and NED at the time of analysis. The burden of intracranial disease at diagnosis was low, and a third of patients had no extracranial disease. Nearly all patients received immunotherapy, of whom half had immunotherapy concurrent with RT. Nearly half of patients who survived more than 5 years did so despite having intracranial progression after initial RT for their mBM. Nearly a quarter of patients had histologically proven RN, suggesting an enhanced immune response to RT in this cohort. Prior studies suggest a correlation between RN and increased intracranial response to RT. Future efforts should characterize the post-treatment radiographic features and other correlatives that differentiate this cohort from the general population with mBM. These results demonstrate an astounding outcome in some patients with limited volume mBM treated in the modern era.

Survival of patients with stage IIIC and IIID melanomas with nodal metastases in the light of new therapies.

Within stage III melanoma prognosis and outcomes significantly vary. Advances in systemic therapy improved prognosis in metastatic melanoma. Adjuvant therapy in stage III significantly lowered relapses, although the effect on survival is less evident. Analysis of treatment results in stage IIIC and IIID before introduction of the modern adjuvant therapy, but after introduction of the effective systemic therapy in metastatic relapse, is needed. To analyse the clinical outcomes in patients with stage IIIC and IIID melanoma before the introduction of the novel adjuvant therapy. Consecutive stage IIIC and IIID melanoma patients treated in 2015-2018 in 4 reference centres in Poland were enrolled in the analysis of RFS and OS (in-transit metastases excluded). Median follow-up was 26.6 months (1.7-67.2). There were 224 stage IIIC and 49 stage IIID patients. Recurrence was observed in 170 (62.2%); 102 (45.5%) deaths in stage IIIC and 28 (57.1%) in stage IIID were reported. RFS and OS were better in stage IIIC compared to stage IIID. RFS and OS in the IIIC group were 19.7 and 36.2 months, respectively, and in IIID - 8.9 and 27.8 months, respectively. The survival of patients with high-risk melanomas has improved in recent years, however, it is still unsatisfactory. The major changes in melanoma management related to the introduction of the adjuvant therapy require further careful observation.

Bioinformatic and Machine Learning Applications in Melanoma Risk Assessment and Prognosis: A Literature Review.

Over 100,000 people are diagnosed with cutaneous melanoma each year in the United States. Despite recent advancements in metastatic melanoma treatment, such as immunotherapy, there are still over 7000 melanoma-related deaths each year. Melanoma is a highly heterogenous disease, and many underlying genetic drivers have been identified since the introduction of next-generation sequencing. Despite clinical staging guidelines, the prognosis of metastatic melanoma is variable and difficult to predict. Bioinformatic and machine learning analyses relying on genetic, clinical, and histopathologic inputs have been increasingly used to risk stratify melanoma patients with high accuracy. This literature review summarizes the key genetic drivers of melanoma and recent applications of bioinformatic and machine learning models in the risk stratification of melanoma patients. A robustly validated risk stratification tool can potentially guide the physician management of melanoma patients and ultimately improve patient outcomes.

Clinical Predictors of Response to Anti-PD-1 First-Line Treatment in a Single-Centre Patient Cohort: A Real-World Study

AimsCutaneous melanoma is one of the most immunogenic tumours. Immunotherapy with checkpoint inhibitors, such as anti-PD-1 antibodies, has significantly improved the prognosis in metastatic melanoma. However, only half of the patients respond to this therapy and have a favourable outcome. Identifying factors associated with treatment failure and early identification of responders are both important to select the best treatment approach for each patient. The aim of our study was to investigate clinical biomarkers of response to treatment with anti-PD-1 antibodies. Materials and methodsWe selected all patients with stage IV melanoma (n = 147), subjected to first-line treatment with anti-PD-1 in the last 10 years. We investigated the associations between patients' different clinical features and progression-free survival, using the Cox proportional hazards models. ResultsIn the multivariate analysis, an increased risk of disease progression was observed among patients with stage M1d metastases (hazard ratio 3.30; 95% confidence interval 1.58–6.91), compared with patients with stage M1a-M1b. Moreover, the risk of progression was greater in patients with the Eastern Cooperative Oncology Group Performance Status (ECOG PS) 1 (hazard ratio 2.04; 95% confidence interval 1.02–4.06) and in patients with ECOG PS ≥ 2 (hazard ratio 2.19; 95% confidence interval 1.05–4.55) compared with ECOG PS 0. High levels of lactate dehydrogenase (hazard ratio 2.06; 95% confidence interval 1.18–3.59) and the presence of respiratory diseases (hazard ratio 4.14; 95% confidence interval 1.42–12.0) at the beginning of anti-PD-1 treatment were also associated with an increased risk of disease progression. In a subgroup analysis, neutrophil count and neutrophil/lymphocyte ratio before anti-PD-1 treatment were higher in patients who underwent disease progression. ConclusionIn our study population, independent predictors of disease progression among patients treated with first-line anti-PD-1 were as follows: ECOG PS, staging, lactate dehydrogenase and the presence of respiratory diseases.

Construction of competing endogenous RNA interaction network as prognostic markers in metastatic melanoma.

Malignant melanoma (MM) is a malignant tumor originating from melanocytes, with high aggressiveness, high metastasis and extremely poor prognosis. MM accounts for 4% of skin cancers and 80% of mortality, and the median survival of patients with metastatic melanoma is only about 6 months, with a five-year survival rate of less than 10%. In recent years, the incidence of melanoma has gradually increased and has become one of the serious diseases that endanger human health. Competitive endogenous RNA (ceRNA) is the main model of the mechanism by which long chain non-coding RNAs (lncRNAs) play a regulatory role in the disease. LncRNAs can act as a “sponge”, competitively attracting small RNAs (micoRNAs; miRNAs), thus interfering with miRNA function, and affect the expression of target gene messenger RNAs (mRNAs), ultimately promoting tumorigenesis and progression. Bioinformatics analysis can identify potentially prognostic and therapeutically relevant differentially expressed genes in MM, finding lncRNAs, miRNAs and mRNAs that are interconnected through the ceRNA network, providing further insight into gene regulation and prognosis of metastatic melanoma. Weighted co-expression networks were used to identify lncRNA and mRNA modules associated with the metastatic phenotype, as well as the co-expression genes contained in the modules. A total of 17 lncRNAs, six miRNAs, and 11 mRNAs were used to construct a ceRNA interaction network that plays a regulatory role in metastatic melanoma patients. The prognostic risk model was used as a sorter to classify the survival prognosis of melanoma patients. Four groups of ceRNA interaction triplets were finally obtained, which miR-3662 might has potential implication for the treatment of metaststic melanoma patients, and futher experiments confirmed the regulating relationship and phenotype of this assumption. This study provides new targets to regulate metastatic process, predict metastatic potential and indicates that the miR-3662 can be used in the treatment of melanoma.

Prognostic value of blood cell count-derived ratios in BRAF-mutated metastatic melanoma.

The treatment and prognosis of metastatic melanoma have changed during the last decade to include immunotherapy or targeted therapy as standard therapeutic options for BRAF-mutated melanoma. However, predictive and/or prognostic markers are lacking, especially in clinical situations where several options are available. The aim of this study was to determine the association of pre-therapeutic blood cell count-derived ratios (BCDR) with survival in patients with BRAF-mutated metastatic melanoma. We evaluated the prognostic role of BCDR in therapy-naïve patients with BRAF-mutated metastatic melanoma treated with immune checkpoint inhibitors or targeted therapy. The impact of BCDR on survival was analysed using univariate and multivariate Cox proportional hazard models. We enrolled 46 patients treated with BRAF inhibitors and 20 patients who received anti-PD-1 checkpoint inhibitors. The median progression-free survival (PFS) and overall survival (OS) were 8.3 and 18.2 months, respectively, with no statistical difference between groups. The objective response rate was 39% (30% in the anti-PD-1 and 44% in the targeted therapy groups). Baseline BCDR values were associated with improved PFS and OS in the immunotherapy group. Only the platelet-to-lymphocyte ratio (PLR) was associated with OS and PFS in the targeted therapy group. Independent prognostic indicators for PFS were lactate dehydrogenase, PLR and the lymphocyte-to-monocyte ratio (LMR) and those for OS were LMR, toxicity and the number of initial metastases. BCDR had a substantial prognostic value in patients with BRAF-mutated metastatic melanoma treated with immune checkpoint inhibitors. However, a prognostic role for BCDR seemed less apparent in patients treated with targeted therapies.

Current status of intralesional agents in treatment of malignant melanoma.

Prognosis of metastatic melanoma has undergone substantial improvement with the discovery of checkpoint inhibitors. Immunotherapies and targeted therapies have improved the median overall survival (OS) of metastatic melanoma from 6 months to more than 3 years. However, still about half of the patients die due to uncontrolled disease. Therefore, multiple strategies are currently being investigated to improve outcomes. One such strategy is intralesional/intratumoral (IT) therapies which can either directly kill the tumor cells or make the tumor more immunogenic to be recognized by the immune system. Talimogene laherparepvec (T-VEC), an oncolytic virus, is the first FDA approved IT therapy. This review focuses on the current status of IT agents currently under clinical trials in melanoma. Reviewed therapies include T-VEC, T-VEC with immune checkpoint inhibitors including ipilimumab and pembrolizumab or other agents, RP1, OrienX010, Canerpaturev (C-REV, HF10), CAVATAK (coxsackievirus A21, CVA21) alone or in combination with checkpoint inhibitors, oncolytic polio/rhinovirus recombinant (PVSRIPO), MAGE-A3-expressing MG1 Maraba virus, VSV-IFNbetaTYRP1, suicide gene therapy, ONCOS-102, OBP-301 (Telomelysin), Stimulation of Interferon Genes Pathway (STING agonists) including DMXAA, MIW815 (ADU-S100) and MK-1454, PV-10, toll-like receptors (TLRs) agonists including TLR-9 agonists (SD-101, CMP-001, IMO-2125 or tilsotolimod, AST-008 or cavrotolimod, MGN1703 or lefitolimod), CV8102, NKTR-262 plus NKTR-214, LHC165, G100, intralesional interleukin-2, Daromun (L19IL2 plus L19TNF), Hiltonol (poly-ICLC), electroporation including calcium electroporation and plasmid interleukin-12 electroporation (pIL-12 EP), IT ipilimumab, INT230-6 (cisplatin and vinblastine with an amphiphilic penetration enhancer), TTI-621 (SIRPαFc), CD-40 agonistic antibodies (ABBV-927 and APX005M), antimicrobial peptide LL37 and other miscellaneous agents.

Treatment Following Progression in Metastatic Melanoma: the State of the Art from Scientific Literature to Clinical Need.

In the last few years, the advent of targeted therapy and immunotherapy has improved the management and the prognosis of metastatic melanoma, but the spread of resistance mechanisms can lead to disease progression. The clinical management in this setting can be challenging because the oncologist has to decide what is the best treatment strategy among therapy beyond progression (TBP), therapy change, and the rechallenge approach. This review of the relevant scientific literature is intended to clarify which patients with progressing metastatic melanoma will benefit from continuation of ongoing therapy and which ones will not. The data are based on a total of about 4300 patients coming from the main retrospective studies in the chosen field. The article body is divided into four sections which analyze respectively the targeted therapy beyond progression, the immunotherapy beyond progression, the possible treatment sequences, and finally the rechallenge strategy. Despite the possible approaches of TBP or rechallenge, the patient may not have an optimal response and may need new therapy, which is currently missing. To broaden the pharmacological offer in the fight against melanoma, cancer research is studying new disease targets, like the NRAS, PI3K, and cKIT pathways or combination treatment of targeted therapy plus immunotherapy. Despite the limitations of this work, mainly due to the limited number of studies, their retrospective nature and the lack of comparative studies, the analysis performed allows us to draw some important conclusions: therapy beyond progression, both targeted therapy and immunotherapy, represents a valid treatment option with positive effects on disease control and survival outcomes for patients with low clinical risk, expressed as low disease burden, normal LDH levels, and good performance status; moreover, the prognosis and quality of life of these patients improve when TBP is associated with locoregional treatments. In patients with progressive metastatic melanoma and high clinical risk (high disease burden, high LDH levels, and poor performance status), it is recommended to change therapy, without ever forgetting the possibility of enrolling the patient in a clinical trial. Finally, an efficacious treatment alternative is the rechallenge strategy; this approach consists in a re-treatment with the same drug after a variable interval of discontinuation. Preliminary studies seem to have demonstrated that patients retreated with targeted therapy achieved a greater benefit if they had a low clinical risk and if the drug doublet (BRAF + MEK inhibitors) was used. On the side of immunotherapy, the rechallenge strategy produced a major benefit in patients who prior experienced a severe toxic episode.

Screening of metabolic modulators identifies new strategies to target metabolic reprogramming in melanoma

The prognosis of metastatic melanoma remains poor due to de novo or acquired resistance to immune and targeted therapies. Previous studies have shown that melanoma cells have perturbed metabolism and that cellular metabolic pathways represent potential therapeutic targets. To support the discovery of new drug candidates for melanoma, we examined 180 metabolic modulators, including phytochemicals and anti-diabetic compounds, for their growth-inhibitory activities against melanoma cells, alone and in combination with the BRAF inhibitor vemurafenib. Two positive hits from this screen, 4-methylumbelliferone (4-MU) and ursolic acid (UA), were subjected to validation and further characterization. Metabolic analysis showed that 4-MU affected cellular metabolism through inhibition of glycolysis and enhanced the effect of vemurafenib to reduce the growth of melanoma cells. In contrast, UA reduced mitochondrial respiration, accompanied by an increase in the glycolytic rate. This metabolic switch potentiated the growth-inhibitory effect of the pyruvate dehydrogenase kinase inhibitor dichloroacetate. Both drug combinations led to increased production of reactive oxygen species, suggesting the involvement of oxidative stress in the cellular response. These results support the potential use of metabolic modulators for combination therapies in cancer and may encourage preclinical validation and clinical testing of such treatment strategies in patients with metastatic melanoma.

Trends in the prognosis of metastatic melanoma in the era of targeted therapy and immunotherapy: A single-institution survey in Japan.

Advances in anticancer therapy, including the development of targeted therapy and immunotherapy, have drastically changed treatment options for metastatic melanoma. However, to date, only a few studies have been published that directly compare overall survival (OS) before and after introduction of these new therapeutic options in Japan. We retrospectively surveyed patients with metastatic melanoma treated in our hospital between 1989 and 2019 to investigate the OS benefit of the new therapies. A total of 115 patients with metastatic melanoma (cutaneous origin, 92; mucosal, 14; uveal, two) were included in the study. Kaplan-Meier analysis showed that the patient group receiving targeted therapy/immunotherapy (TT/IT) (n=47) had a median OS of 19.0months, which was longer than that in patients receiving conventional chemotherapy (n=42, 8.0months) or no treatment (n=26, 6.0months) (P<0.001). In the subgroup analysis performed for the TT/IT group, patients of younger age and with the BRAF mutation had significantly improved OS. As the number of treatment lines increased, the median OS tended to become longer. Our real-world data confirmed an improvement of median OS upon the introduction of the new therapies for metastatic melanoma. However, the long-term OS benefit was limited, possibly because of racial differences in some of the clinical characteristics. To improve the overall melanoma prognosis, the entire treatment strategy, including perioperative therapy needs strengthening.

Circulating Tumour DNA Is an Independent Prognostic Biomarker for Survival in Metastatic BRAF or NRAS-Mutated Melanoma Patients.

Circulating tumour DNA (ctDNA) can be used to identify gene alterations. The purpose of this study was to determine whether the detection of ctDNA, based on the identification of BRAF and NRAS mutations before systemic treatment initiation, was associated with the prognosis of metastatic melanoma. In total, 68 BRAF or NRAS-mutated stage IV or unresectable stage III metastatic cutaneous melanoma patients were included and tested for the presence of BRAF and NRAS mutations in circulating DNA before treatment initiation, using the Cobas BRAF/NRAS Mutation Test (Roche). The expected mutation was detected in the plasma of 34/68 patients (50% sensitivity). ctDNA detection was associated with AJCC stage, along with the number and nature of metastases. ctDNA was less frequently detected in NRAS-mutated than in BRAF-mutated melanoma (36% and 66%, respectively). At initiation of first-line treatment, ctDNA detection was associated with poor prognosis in Progression Free Survival (PFS) and Overall Survival (OS) in univariate analysis (log-rank: p = 0.002 and p < 0.0001, respectively). In multivariate analysis, ctDNA detection was an independent factor of poor prognosis in OS, after adjustment for AJCC stage, number and nature of metastases and gender (HR = 4.384; 95% CI: (1.308; 14.699); p = 0.017).

Salvage chemotherapy in the treatment of metastatic melanoma after progression on immunotherapy.

e22019 Background: Immune-checkpoint inhibitors (ICI) have dramatically altered the prognosis of metastatic melanoma (MM); however, fifty percent of patients will not respond to ICI. For these patients, the next choice of treatment includes targeted therapy or a clinical trial if eligible. If these treatment choices have already been utilized or are not available to the patient, there may be value in attempting a course of salvage chemotherapy (CTX). Limited clinical trial evidence has demonstrated unexpected efficacy of CTX after prior progression on ipilimumab, offering higher disease control rates than expected from what is seen in first-line chemotherapy. The phenomenon of a “priming” effect of ICI on CTX efficacy has been shown in patients of various solid tumors after progression on anti-PD1/PD-L1 therapy. The purpose of this retrospective analysis is to evaluate the efficacy of salvage CTX after prior ICI therapy for patients with MM. Patients with ocular melanoma were excluded, as this tumor subtype is known to have reduced response to immunotherapy. Methods: By retrospective analysis, patients were included under an IRB approved waiver of consent. We identified patients with MM treated with ICI therapy between Jan, 2011 and July, 2019 who were subsequently treated with salvage CTX as a result of progression of disease (POD). Salvage CTX included dacarbazine, carboplatin, temozolomide, paclitaxel, or a combination. We assessed response rate, duration of response, and time to progression (TTP) from the onset of salvage CTX. Results: A total of 22 patients who satisfied the above criteria were identified. The majority of this population had a course of single agent ICI as well as a course of combination ICI prior to salvage CTX (72.7%, n = 16/22). 13 (59.1%) patients had POD on salvage CTX with a median TTP of 10.9 weeks. 9 (40.9%) patients responded to salvage CTX. 3 (13.6%) patients achieved a complete response, 4 (18.2%) patients achieved a partial response and 2 (9.1%) patients achieved stable disease. Mean durability of response was 53.6 weeks, ranging from 7-194 weeks. Conclusions: ICI “priming” prior to salvage CTX efficacy may improve disease responsiveness to CTX. This sequence of therapy may offer patients another reasonable treatment option. Despite the small sample size of this study, a prospective clinical trial in MM exploring CTX following ICI progression should be considered.

Human Plasmacytoid Dendritic Cells and Cutaneous Melanoma.

The prognosis of metastatic melanoma (MM) patients has remained poor for a long time. However, the recent introduction of effective target therapies (BRAF and MEK inhibitors for BRAFV600-mutated MM) and immunotherapies (anti-CTLA-4 and anti-PD-1) has significantly improved the survival of MM patients. Notably, all these responses are highly dependent on the fitness of the host immune system, including the innate compartment. Among immune cells involved in cancer immunity, properly activated plasmacytoid dendritic cells (pDCs) exert an important role, bridging the innate and adaptive immune responses and directly eliminating cancer cells. A distinctive feature of pDCs is the production of high amount of type I Interferon (I-IFN), through the Toll-like receptor (TLR) 7 and 9 signaling pathway activation. However, published data indicate that melanoma-associated escape mechanisms are in place to hijack pDC functions. We have recently reported that pDC recruitment is recurrent in the early phases of melanoma, but the entire pDC compartment collapses over melanoma progression. Here, we summarize recent advances on pDC biology and function within the context of melanoma immunity.

Melanoma: the new perspectives from clinical and translational research.

The prognosis of metastatic melanoma has not changed throughout the 20th century. However, in the last decade, we have witnessed a continuous improvement in survival, with many long-term survivors. These results are largely because of the simultaneous development of the knowledge in the biology of metastatic malignant melanoma and of the relationship between the disease and the host's immune system that allowed the development of effective new treatments. In this overview, we summarize the therapies available today, their biological rationale, and the research field currently under investigation divided into three main chapters: target therapies, immunotherapies, and their combination.

Secondary Gastrointestinal Melanoma of Unclear Origin

Metastatic melanoma has a predilection for the lungs, bones, GI tract, and brain. Overall, the incidence of GI organ metastases in metastatic melanoma is 43%, with the liver being the most common (58.3% of cases). The stomach is a much rarer GI destination: 7th overall after liver, peritoneum, pancreas, small bowel, spleen, and colon. An 89 y.o. male with past medical history significant for atrial fibrillation and COPD presented with difficulty swallowing. He had been having increasing dysphagia to solids over the past year and was now unable to swallow liquids. He admitted to 20-pound weight loss over the preceding year. Patient had a smoking history though he quit in 1946. Previous esophagogastroduodenoscopy a week prior to admission showed esophageal narrowing for which received Botox injections for suspected achalasia. On admission, the patient was hemodynamically stable though appeared malnourished. Labs were unremarkable. A contrast enhanced CT thorax showed a 7.5cm mass at the gastroesophageal junction (GEJ). [Fig. 1.] He underwent endoscopic ultrasound which showed a lobulated mass just below GEJ measuring 68 x 55 mm. [Fig. 2]. Biopsy showed an epithelioid/ spindle malignant tumor consistent with metastatic melanoma. [Fig. 3] The patient was deemed to be a poor surgical candidate and instead had a percutaneous endoscopic gastrostomy tube placed with plans for palliative chemotherapy. No primary lesion was identified.2627_A Figure 1. CT Thorax w/ contrast showing the 7.5cm mass at the GE Junction (between red arrows).2627_B Figure 2. Mass abutting gastric wall on EUS.2627_C Figure 3. Fine needle aspiration of the perigastric mass displays cellular smears composed of sheets or clusters of atypical epithelioid cells (A) along with scattered loosely cohesive epithelioid to spindle cells. By immunohistochemistry, the neoplastic cells are positive for melanoma cocktail (B), S100 protein (C) and SOX10 (D) while exhibiting no immunoreactivity with CD117, DOG-1, CD45, CD3, CD20, desmin, pan-cytokeratin (AE1/AE3), chromogranin and CD99. The morphologic and immunohistochemical features are most consistent with metastatic melanoma.The prognosis of metastatic melanoma is poor, with a mean survival of only 6-8 months and a 5-year survival rates less than 10%. Outcomes also depend on the site of metastases, with worse survival rates in those with metastases to visceral organs, particularly the GI tract. Treatment of metastatic melanoma of the GI tract include surgical resection, immunotherapy, and biochemotherapy. Mean survival for curative resection is 48.9 months, 5.4 months for palliative procedures, and 5.7 months for non-surgical interventions. As in this case, 4-10% of metastatic melanomas present with occult primary lesion. Theories on mechanism include the primary lesion undergoing complete regression or, falling under detection threshold. Histopathologic regression within melanoma has been reported to be 6 times that of other cancers.

Abstract A38: Blood-based T cell biomarkers and soluble PD-L1 predict responses and immune-related toxicity to PD-1 blockade in melanoma and lung cancer

Abstract Despite unprecedented successes with immune checkpoint blockade in advanced cancers, these agents provide durable clinical benefit in only a subset of patients. In addition, the clinical management of patients receiving immune checkpoint blockade remains quite challenging due to the unpredictable and kinetically heterogeneous responses which can manifest as late responses, pseudoprogression, or hyperprogression in subsets of patients. The dynamics and heterogeneity of programmed cell death protein ligand 1 (PD-L1, aka B7-H1) expression confound its use as a predictive biomarker in cancer immunotherapy, but blood-based biomarkers have the potential to predict responders and detect mechanisms of resistance to immunotherapy. We previously reported that Bim (BH3-only protein) is a downstream signaling molecule of the PD-1 pathway, and that Bim levels in circulating tumor-reactive T-cells reflected patient responses to anti-PD-1 therapy in melanoma. We also discovered the existence of soluble PD-L1 (sPD-L1) in the plasma of cancer patients and showed a correlation of sPD-L1 with cancer stages in renal cell carcinoma and with prognosis in metastatic melanoma. Here we evaluated the frequency of tumor-reactive T cells with Bim expression along with effector memory profile and sPD-L1 as biomarkers of response in a new cohort of patients with metastatic melanoma and lung cancer undergoing anti-PD-1 therapy. We recruited 100 cancer patients treated with anti-PD-1 therapy who had peripheral blood collected at baseline and at each subsequent radiographic tumor evaluation. Frequencies of Bim+ and effector memory CD8+ T cells were measured by flow cytometry in gated tumor-reactive CD11a high PD1+ CD8+ T cells. We also measured levels of sPD-L1 in plasma at baseline and serially during treatment with ELISA. Baseline T cell markers and sPD-L1 levels and their percent changes in patients who had a radiographic response were compared to those who had progressive disease (PD). We found that patients with objective response after 4 cycles of anti-PD-1 therapy had higher frequency of Bim+ CD8+ T cells at baseline compared to patients with PD (mean 43% vs. 30%, P=0.0484). The frequencies of Bim+ T cells decreased significantly after the first 3 months of treatment in responders compared with progressors (mean -16% vs. + 40% P=0.0111). The frequency of effector memory CD8+ T cells also dramatically increased in responders in 3-6 months after anti-PD-1 therapy (mean 89% vs. 9.56%, p=0.002). High baseline sPD-L1 was associated with progression on anti-PD-1 therapy (mean 2.8 ng/mL vs. 0.7 ng/mL, p=0.07) or development of immune-related toxicities and the levels increased by 12 weeks in patients progressing on therapy. Conclusion: Measurements of T cell biomarkers (Bim and effector memory) and sPD-L1 levels provide a new noninvasive way to predict and monitor patient responses to anti-PD-1 monotherapy in melanoma and lung cancers. Note: This abstract was not presented at the conference. Citation Format: Roxana S. Dronca, Aaron Mansfield, Xin Liu, Susan Harrington, Elizabeth Enninga, Svetomir Markovic, Lisa Kottschade, Rob Mcwilliams, Matthew Block, Wendy Nevala, Michael Thompson, Haidong Dong. Blood-based T cell biomarkers and soluble PD-L1 predict responses and immune-related toxicity to PD-1 blockade in melanoma and lung cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A38.

The impact of effective systemic therapies on surgery for stage IV metastatic melanoma

Background: The prognosis of metastatic melanoma has drastically improved in recent years with the evolution of effective systemic therapies (EST). The impact of EST on the role of surgery in Stage IV melanoma is unclear. We sought to characterise the patterns and outcomes of surgery in patients with Stage IV melanoma before and after the introduction of EST.