Future of radiation therapy for malignant melanoma in an era of newer, more effective biological agents

Epidemiology of brain metastases and leptomeningeal disease

Brain metastases affect a significant percentage of patients with advanced extracranial malignancies. Yet, the incidence of brain metastases remains poorly described, largely due to limitations of population-based registries, a lack of mandated reporting of brain metastases to federal agencies, and historical difficulties with delineation of metastatic involvement of individual organs using claims data. However, in 2016, the Surveillance Epidemiology and End Results (SEER) program released data relating to the presence vs absence of brain metastases at diagnosis of oncologic disease. In 2020, studies demonstrating the viability of utilizing claims data for identifying the presence of brain metastases, date of diagnosis of intracranial involvement, and initial treatment approach for brain metastases were published, facilitating epidemiologic investigations of brain metastases on a population-based level. Accordingly, in this review, we discuss the incidence, clinical presentation, prognosis, and management patterns of patients with brain metastases. Leptomeningeal disease is also discussed. Considerations regarding individual tumor types that commonly metastasize to the brain are provided.

Laser Interstitial Thermal Therapy for Metastatic Melanoma After Failed Radiation Therapy: A Case Series

BACKGROUND

Laser interstitial thermal therapy (LITT) is a growing technology to treat a variety of brain lesions. It offers an alternative to treatment options, such as open craniotomy and stereotactic radiosurgery.

OBJECTIVE

To analyze our experience using LITT for metastatic melanoma.

METHODS

This is a retrospective chart review of the patients from our institution. Our case series involves 5 patients who had previously failed radiation treatment.

RESULTS

Our patients have low complication rates and short hospital stays. Both are considerably lower when compared to the literature for metastatic melanoma.

CONCLUSION

LITT is a safe therapy, with few complications and short hospital stays.

Using salvage Boron Neutron Capture Therapy (BNCT) for recurrent malignant brain tumors in Taiwan

Radiation therapy has an irreplaceable role in modern oncologic therapy, thanks to the advanced radiation techniques developed in recent decades. However, photon-resistant cases are sometimes encountered. Boron Neutron Capture Therapy (BNCT) is a highly selective radiotherapy technique due to the high tumor to tissue ratio of boronophenylalanine (BPA), the unique medication used for the BNCT treatment reaction. In this study, we report on three special patients with malignant brain tumors treated with BNCT.

Impact of Sequencing Radiation Therapy and Immune Checkpoint Inhibitors in the Treatment of Melanoma Brain Metastases

PURPOSE

Melanoma brain metastases (MBM) occur in ∼50% of melanoma patients. Although both radiation therapy (RT) and immune checkpoint inhibitor (ICI) are used alone or in combination for MBM treatment, the role of this combination and how these treatments could best be sequenced remains unclear.

METHODS AND MATERIALS

We conducted a retrospective analysis of patients with resected MBM who underwent treatment with RT, ICI, or a combination of RT and ICI. Among the latter, we specifically investigated the differential gene expression via RNA-sequencing between patients who received RT first then ICI (RT → ICI) versus ICI first then RT (ICI → RT). We used a glycoprotein-transduced syngeneic melanoma mouse model for validation experiments.

RESULTS

We found that for patients with resected MBM, a combination of RT and ICI confers superior survival compared with RT alone. Specifically, we found that RT → ICI was superior compared with ICI → RT. Transcriptome analysis of resected MBM revealed that the RT → ICI cohort demonstrated deregulation of genes involved in apoptotic signaling and key modulators of inflammation that are most implicated in nuclear factor kappa-light-chain-enhancer of activated B cells signaling. In a preclinical model, we showed that RT followed by anti-programmed death-ligand 1 therapy was superior to the reverse sequence of therapy, supporting the observations we made in patients with MBM.

CONCLUSIONS

Our study provides initial insights into the optimal sequence of RT and ICI in the treatment of MBM after surgical resection. Prospective studies examining the best sequence of RT and ICI are necessary, and our study contributes to the rationale to pursue these.

Histamine receptors and cancer pharmacology: an update

In the present review, we will discuss the recent advances in the understanding of the role of histamine and histamine receptors in cancer biology. The controversial role of the histaminergic system in different neoplasias including gastric, colorectal, oesophageal, oral, pancreatic, liver, lung, skin, blood and breast cancers will be reviewed. The expression of histamine receptor subtypes, with special emphasis on the histamine H4 receptor, in different cell lines and human tumours, the signal transduction pathways and the associated biological responses as well as the in vivo treatment of experimental tumours with pharmacological ligands will be described. The presented evidence demonstrates that histamine regulates cancer-associated biological processes during cancer development in multiple cell types, including neoplastic cells and cells in the tumour micro-environment. The outcome will depend on tumour cell type, the level of expression of histamine receptors, signal transduction associated with these receptors, tumour micro-environment and histamine metabolism, reinforcing the complexity of cancer disease. Findings show the pivotal role of H4 receptors in the development and progression of many types of cancers, and considering its immunomodulatory properties, the H4 receptor appears to be the most promising molecular therapeutic target for cancer treatment within the histamine receptor family. Furthermore, the H4 receptor is differentially expressed in tumours compared with normal tissues, and in most cancer types in which data are available, H4 receptor expression is associated with clinicopathological characteristics, suggesting that H4 receptors might represent a novel cancer biomarker. LINKED ARTICLES: This article is part of a themed section on New Uses for 21st Century. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.3/issuetoc.

Growth Hormone Upregulates Melanocyte-Inducing Transcription Factor Expression and Activity via JAK2-STAT5 and SRC Signaling in GH Receptor-Positive Human Melanoma

Growth hormone (GH) facilitates therapy resistance in the cancers of breast, colon, endometrium, and melanoma. The GH-stimulated pathways responsible for this resistance were identified as suppression of apoptosis, induction of epithelial-to-mesenchymal transition (EMT), and upregulated drug efflux by increased expression of ATP-binding cassette containing multidrug efflux pumps (ABC-transporters). In extremely drug-resistant melanoma, ABC-transporters have also been reported to mediate drug sequestration in intracellular melanosomes, thereby reducing drug efficacy. Melanocyte-inducing transcription factor (MITF) is the master regulator of melanocyte and melanoma cell fate as well as the melanosomal machinery. MITF targets such as the oncogene MET, as well as MITF-mediated processes such as resistance to radiation therapy, are both known to be upregulated by GH. Therefore, we chose to query the direct effects of GH on MITF expression and activity towards conferring chemoresistance in melanoma. Here, we demonstrate that GH significantly upregulates MITF as well as the MITF target genes following treatment with multiple anticancer drug treatments such as chemotherapy, BRAF-inhibitors, as well as tyrosine-kinase inhibitors. GH action also upregulated MITF-regulated processes such as melanogenesis and tyrosinase activity. Significant elevation in MITF and MITF target gene expression was also observed in mouse B16F10 melanoma cells and xenografts in bovine GH transgenic (bGH) mice compared to wild-type littermates. Through pathway inhibitor analysis we identified that both the JAK2-STAT5 and SRC activities were critical for the observed effects. Additionally, a retrospective analysis of gene expression data from GTEx, NCI60, CCLE, and TCGA databases corroborated our observed correlation of MITF function and GH action. Therefore, we present in vitro, in vivo, and in silico evidence which strongly implicates the GH-GHR axis in inducing chemoresistance in human melanoma by driving MITF-regulated and ABC-transporter-mediated drug clearance pathways.

The Use of ß-Elemene to Enhance Radio Sensitization of A375 Human Melanoma Cells

Objective

Melanoma is the most malignant and severe type of skin cancer. It is a tumor with a high risk of metastasis and resistant to conventional treatment methods (surgery, radiotherapy, and chemotherapy). β-elemene is the most active constituent of Curcuma wenyujin which is a non-cytotoxic antitumor drug, proved to be effective in different types of cancers. The study aimed to investigate the therapeutic effects of β-elemene in combination with radiotherapy on A375 human melanoma.

Materials and Methods

In this experimental study, human melanoma cells were grown in the monolayer culture model. The procedure of the treatment was performed by the addition of different concentrations of β-elemene to the cells. Then, the cells were exposed to 2 and 4 Gy X-ray in different incubation times (24, 48, and 72 hours). The MTT assay was used for the determination of the cell viability. To study the rate of apoptosis response to treatments, the Annexin V/PI assay was carried out.

Results

The results of the MTT assay showed β-elemene reduced the cell proliferation in dose- and time-dependent manners in cells exposed to radiation. Flow cytometry analysis indicated that β-elemene was effective in the induction of apoptosis. Furthermore, the combination treatment with radiation remarkably decreased the cells proliferation ability and also enhanced apoptosis. For example, cell viability in a group exposed to 40 µg/ml of β-elemene was 80%, but combination treatment with 6 MV X beam at a dose of 2 Gy reduced the viability to 61%.

Conclusion

Our results showed that β-elemene reduced the proliferation of human melanoma cancer cell through apoptosis. Also, the results demonstrated that the radio sensitivity of A375 cell line was significantly enhanced by β-elemene. The findings of this study indicated the efficiency of β-elemene in treating melanoma cells and the necessity for further research in this field.

Utilizing 808 nm laser for sensitizing of melanoma tumors to megavoltage radiation therapy

Melanotic melanoma has high content of melanin and laser can destroy melanin-containing cells through thermal effect. In this study, the therapeutic effect of 808 nm laser therapy was investigated on B16-F10 melanoma tumor growth and tumor-bearing mice survival time. In addition, as laser can destroy melanin as the main cause of melanoma radioresistance, the effect of laser administration to enhance radiation therapy efficacy at B16-F10 cancer cells was evaluated in vitro and in vivo. Laser therapy (1 W/cm² × 4 min) could cause significant (P < 0.05) inhibition of melanoma tumors' growth (~ 61%) and about three times increase of the tumor-bearing mice survival time in comparison with no-treatment group. In addition, the mice which were treated with 1 W/cm² × 4 min laser administration plus 6 Gy megavoltage radiation therapy exhibited ~ 68% lesser tumors' volume and 27 days increase of survival time in comparison with 6 Gy irradiated tumor-bearing mice. Also, significantly higher (P < 0.05) tumor necrosis percentage was observed at the histopathological slides of 1 W/cm² × 4 min laser + RT treated mice tumors (57 ± 12%) in comparison with radiation therapy group (31 ± 10%). Therefore, not only laser therapy can inhibit melanoma tumors' growth per se but also its combination with radiation therapy can cause a significant enhancement of radiation therapy efficacy. The laser administration can be used as a radiosensitizing method for melanotic melanoma radiation therapy.

HDAC2 Inhibitor Valproic Acid Increases Radiation Sensitivity of Drug-Resistant Melanoma Cells

Resistance to anticancer drugs limits the effectiveness of chemotherapy in cancers. Melanoma cell lines B16F10C and A375C (parental) and B16F10R and A375R (drug-resistant sublines) were used to test radiation sensitization potential of valproic acid (VPA), an inhibitor of Histone deacetylase2 (HDAC2) and LDN193189 (BMP inhibitor). Inhibitors of other signaling pathways were tested for cross-resistance with the resistant cell lines. Cells were pretreated with low concentrations of VPA/ LDN193189 and exposed to 2 Gy radiation for radiation sensitization experiments. Assays-3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), live/dead, clonogenic, and melanin estimation were performed to test the effects of radiation sensitization. Interactions of VPA and HDAC2 were studied in silico. Dose-dependent growth inhibition was observed with all tested drugs. Radiation sensitization of melanoma cells with low dose of VPA induced synergistic cell death, decreased clonogenicity, and decreased melanin content. In silico docking showed two stable interactions between Arg39 of HDAC2 and VPA. In conclusion, pretreatment with low doses of VPA has a potential for sensitizing melanoma cells to low doses of radiation. The binding of VPA to HDAC2 reverses the drug resistance in melanoma and induces the cell death. Sensitization effects of VPA can be used for targeting drug-resistant cancers.

Effects of FOXM1 inhibition and ionizing radiation on melanoma cells

Metastatic melanoma can be highly refractory to conventional radiotherapy and chemotherapy but combinatorial-targeted therapeutics are showing greater promise on improving treatment efficacy. Previous studies have shown that knockdown of Forkhead box M1 (FOXM1) can sensitize various tumor types to radiation-induced cell death. The effect of combining radiation with a small molecule FOXM1 inhibitor, Siomycin A, on growth, death and migration of a metastatic melanoma cell line (SK-MEL-28) that overexpresses this pleiotropic cell cycle regulator was investigated. Siomycin A (SIOA) was found to be a strong inducer of apoptosis, and inhibitor of proliferation and migration in a scratch wound assay in this cell line. Induction of apoptosis occurred at concentrations >1 µM in association with reductions in the constitutive FOXM1 and anti-apoptotic B-cell lymphoma 2 protein levels found in these cells. Single doses of ionizing radiation (0-40 Gy) delivered by linear accelerator caused inhibition of growth and migration without significant induction of cell death. Pretreatment with SIOA did not increase the sensitivity of this melanoma cell line to radiation as observed in other tumor types. These data confirm that as a single agent, SIOA is an effective inducer of cell death and inhibitor of migration in metastatic melanoma cells expressing constitutive FOXM1. In combination with radiation, SIOA pre-treatment, however, may not be of added benefit.

Endoscopic resection of sinonasal mucosal melanoma has comparable outcomes to open approaches

BACKGROUND

Endoscopic endonasal resection (EER) of sinonasal mucosal melanoma (SMM) is a newer surgical alternative to traditional external and/or open resection (OR). Studies on long-term outcomes are necessary to validate EER for this aggressive sinonasal malignancy.

OBJECTIVE

To compare outcomes of EER versus OR in SMM.

METHODS

A case series of patients who underwent surgical resection of SMM at a tertiary-care institution (2000-2015) was studied retrospectively. Demographics, tumor site and stage, surgical approach, surgical margin status, local control, and survival were compared between those who underwent EER and OR.

RESULTS

Twenty-two patients met inclusion criteria. Nine underwent EER and 13 underwent OR. The mean age in the EER and OR groups was similar, 78.7 and 72.3 years, respectively. Two-thirds of patients were women (EER, 66.7%; OR, 61.5%). The nasal cavity was the most common primary tumor site (EER, 77.8%; OR, 84.6%). The local tumor stage in both groups was similar, with the majority of cases being T4 (EER, 55.6%; OR, 61.5%; p = 0.99). Negative margins were achieved in all EERs and in 69.2% of ORs. Median follow-up was 25.0 months for the overall group (range, 1.7-172.9 months), 32.6 months (range, 3.4-58.7 months) for EER and 14.1 months (range, 1.7-172.9 months) for OR cohorts. The 5-year overall survival was statistically similar in both groups (EER, 53.3%; OR, 22.7%; p = 0.214) as was disease-free survival (EER, 55.6%; OR, 22.8%; p = 0.178). Local control, however, was significantly higher in the EER cohort (EER, 85.7%; OR, 37.6%; p = 0.026).

CONCLUSION

In carefully selected patients with sinonasal melanoma, endoscopic surgery with an experienced team may offer comparable survival and improved local control over open surgery. Prospective, multicentered studies with larger cohorts are needed to validate these results.

Malignant Melanoma of the Breast: A Case Report and Review of the Literature

Primary breast melanoma is a rare entity that on routine histology may be mistaken for triple-negative breast cancer. A high degree of clinical suspicion is necessary to make this diagnosis. This case report describes the presentation and treatment of primary breast melanoma.

The influence of postoperative lymph node radiation therapy on overall survival of patients with stage III melanoma, a National Cancer Database analysis

Recently, TROG 02.01 results showed that in stage III melanoma patients with nodal metastasis, adjuvant radiation to lymph node basin after nodal dissection improves lymph node field relapse without an overall survival (OS) benefit. However, this trial was neither designed nor powered to detect an OS difference. In the present study, we analyzed patients in the National Cancer Database (NCDB) with stage III melanoma with pathologically involved nodes and compared survival outcomes of adjuvant radiation and no-radiation cohorts. Inclusion criteria were as follows: age at least 18 years; diagnosed 2003-2011; surgery to regional lymph nodes; pathologically involved lymph nodes; and American Joint Committee on Cancer stage (IIIA-C). We used propensity score matching analysis to compare the OS of patients with similar baseline demographic, clinical, and pathologic characteristics who received adjuvant radiation and no adjuvant radiation. Overall, 912 patients were analyzed with an average age at diagnosis of 54.4 years and a median follow-up time of 5.5 years. In this cohort, the 5-year OS was 69.0, 51.1, and 30.6% for stage IIIA, IIIB, and IIIC, respectively. On propensity score-adjusted multivariate analysis, we found that adjuvant radiation had no statistically significant impact on OS (hazard ratio: 1.09, 95% confidence interval: 0.75-1.58, P=0.640). Furthermore, age older than 60 years, number of nodes, increasing pathologic stage, and absence of immunotherapy correlated with worse OS. In this NCDB analysis, we found that the adjuvant radiotherapy for node-positive, stage III melanoma patients did not improve OS. This is consistent with TROG 02.01; however, there may be patient selection bias not accounted for by the NCDB.

A 14-Protein Signature for Rapid Identification of Poor Prognosis Stage III Metastatic Melanoma

PURPOSE

To validate differences in protein levels between good and poor prognosis American Joint Committee on Cancer (AJCC) stage III melanoma patients and compile a protein panel to stratify patient risk.

EXPERIMENTAL DESIGN

Protein extracts from melanoma metastases within lymph nodes in patients with stage III disease with good (n = 16, >4 years survival) and poor survival (n = 14, <2 years survival) were analyzed by selected reaction monitoring (SRM). Diagonal Linear Discriminant Analysis (DLDA) was performed to generate a protein biomarker panel.

RESULTS

SRM analysis identified ten proteins that were differentially abundant between good and poor prognosis stage III melanoma patients. The ten differential proteins were combined with 22 proteins identified in our previous work. A panel of 14 proteins was selected by DLDA that was able to accurately classify patients into prognostic groups based on levels of these proteins.

CONCLUSIONS AND CLINICAL RELEVANCE

The ten differential proteins identified by SRM have biological significance in cancer progression. The final signature of 14 proteins identified by SRM could be used to identify AJCC stage III melanoma patients likely to have poor outcomes who may benefit from adjuvant systemic therapy.

Effects of ursolic and oleanolic on SK‑MEL‑2 melanoma cells: In vitro and in vivo assays

Among the triterpenoids, oleanolic acid (OA) and its isomer, ursolic acid (UA) are promising therapeutic candidates, with potential benefits in the management of melanoma. In this study, we aimed to examine the in vitro and in vivo anti‑invasive and anti‑metastatic activity of OA and UA to determine their possible usefulness as chemopreventive or chemotherapeutic agents in melanoma. For the in vitro experiments, the anti‑proliferative activity of the triterpenic compounds on SK‑MEL‑2 melanoma cells was examined. The anti‑invasive potential was assessed by testing the effects of the active compound on vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM) adhesion to melanoma cells. Normal and tumor angiogenesis were evaluated in vivo by chicken embryo chorioallantoic membrane (CAM) assay. The two test triterpenoid acids, UA and OA, exerted differential effects in vitro and in vivo on the SK‑MEL‑2 melanoma cells. UA exerted a significant and dose‑dependent anti‑proliferative effect in vitro, compared to OA. The cytotoxic effects in vitro on the melanoma cells were determined by the examining alterations in the cell cycle phases induced by UA that lead to cell arrest in the S phase. Moreover, UA was found to affect SK‑MEL‑2 melanoma cell invasiveness by limiting the cell adhesion capacity to ICAM molecules, but not influencing their adhesion to VCAM molecules. On the whole, in this study, by assessing the effects of the two triterpenoids in vivo, our results revealed that OA had a greater potential to impair the invasive capacity and tumor angiogenesis compared with UA.

Targeting DNA repair by coDbait enhances melanoma targeted radionuclide therapy

Radiolabelled melanin ligands offer an interesting strategy for the treatment of disseminated pigmented melanoma. One of these molecules, ICF01012 labelled with iodine 131, induced a significant slowing of melanoma growth. Here, we have explored the combination of [¹³¹I]ICF01012 with coDbait, a DNA repair inhibitor, to overcome melanoma radioresistance and increase targeted radionuclide therapy (TRT) efficacy. In human SK-Mel 3 melanoma xenograft, the addition of coDbait had a synergistic effect on tumor growth and median survival. The anti-tumor effect was additive in murine syngeneic B16Bl6 model whereas coDbait combination with [¹³¹I]ICF01012 did not increase TRT side effects in secondary pigmented tissues (e.g. hair follicles, eyes). Our results confirm that DNA lesions induced by TRT were not enhanced with coDbait association but, the presence of micronuclei and cell cycle blockade in tumor shows that coDbait acts by interrupting or delaying DNA repair. In this study, we demonstrate for the first time, the usefulness of DNA repair traps in the context of targeted radionuclide therapy.

Strategies to Improve the Efficacy of Dendritic Cell-Based Immunotherapy for Melanoma

Melanoma is a highly aggressive form of skin cancer that frequently metastasizes to vital organs, where it is often difficult to treat with traditional therapies such as surgery and radiation. In such cases of metastatic disease, immunotherapy has emerged in recent years as an exciting treatment option for melanoma patients. Despite unprecedented successes with immune therapy in the clinic, many patients still experience disease relapse, and others fail to respond at all, thus highlighting the need to better understand factors that influence the efficacy of antitumor immune responses. At the heart of antitumor immunity are dendritic cells (DCs), an innate population of cells that function as critical regulators of immune tolerance and activation. As such, DCs have the potential to serve as important targets and delivery agents of cancer immunotherapies. Even immunotherapies that do not directly target or employ DCs, such as checkpoint blockade therapy and adoptive cell transfer therapy, are likely to rely on DCs that shape the quality of therapy-associated antitumor immunity. Therefore, understanding factors that regulate the function of tumor-associated DCs is critical for optimizing both current and future immunotherapeutic strategies for treating melanoma. To this end, this review focuses on advances in our understanding of DC function in the context of melanoma, with particular emphasis on (1) the role of immunogenic cell death in eliciting tumor-associated DC activation, (2) immunosuppression of DC function by melanoma-associated factors in the tumor microenvironment, (3) metabolic constraints on the activation of tumor-associated DCs, and (4) the role of the microbiome in shaping the immunogenicity of DCs and the overall quality of anti-melanoma immune responses they mediate. Additionally, this review highlights novel DC-based immunotherapies for melanoma that are emerging from recent progress in each of these areas of investigation, and it discusses current issues and questions that will need to be addressed in future studies aimed at optimizing the function of melanoma-associated DCs and the antitumor immune responses they direct against this cancer.

Metastatic melanoma: a rare cause of central airway obstruction

A middle-aged woman with recurrent malignant melanoma presented initially with massive left pleural effusion. There was a complete obliteration of the left main bronchus on flexible bronchoscopy caused by a mass. Serial cryo-debulking of the tumour was done under rigid bronchoscopy; however, the outcome was not favourable due to the aggressive tumour growth. Vemurafenib was planned after thoracic radiation. She was not keen for the biologics treatment due to financial constraints. We report a case of central airway obstruction due to recurrent aggressive melanoma. More evaluations are needed on the role of interventional pulmonologist for bronchoscopic debulking of this rapidly growing tumour as well as the role of biological agents in treating such cases.

Ipilimumab and Stereotactic Radiosurgery Versus Stereotactic Radiosurgery Alone for Newly Diagnosed Melanoma Brain Metastases

BACKGROUND

We compared the safety and efficacy of ipilimumab and stereotactic radiosurgery (SRS) to SRS alone for newly diagnosed melanoma brain metastases (MBM).

MATERIALS AND METHODS

We reviewed records of newly diagnosed MBM patients treated with SRS from 2009 to 2013. The primary endpoint of overall survival (OS), and secondary endpoints of local control, distant intracranial failure, and radiation necrosis were compared using Kaplan-Meier method. Univariate and multivariate analysis were performed using the Cox proportional hazards method.

RESULTS

Fifty-four consecutive MBM patients were identified, with 20 (37.0%) receiving ipilimumab within 4 months of SRS. Ipilimumab-treated and non-ipilimumab-treated patients had similar baseline characteristics. No difference in symptomatic radiation necrosis or hemorrhage was identified between cohorts. Compared with patients in the nonipilimumab group, 1 year local control (71.4% vs. 92.3%, P=0.40) and intracranial control (12.7% vs. 29.1%, P=0.59) were also statistically similar. The ipilimumab cohort also had no difference in 1-year OS (37.1% vs. 38.5%, P=0.84). Patients administered ipilimumab within 14 days of SRS had higher 1-year (42.9%) and 2-year OS (42.9%) relative to ipilimumab delivered >14 days (33.8%, 16.9%) and SRS alone (38.5%, 25.7%) but these difference were not statistically significant. Univariate analysis and multivariate analysis both confirmed single brain metastasis, controlled primary, and active systemic disease as predictors for OS.

CONCLUSIONS

Use of ipilimumab within 4 months of SRS seems to be safe, with no increase in radiation necrosis or hemorrhage; however, our retrospective institutional experience with this treatment regimen was not associated with improved outcomes.

Histamine therapeutic efficacy in metastatic melanoma: Role of histamine H4 receptor agonists and opportunity for combination with radiation

The aims of the work were to improve our knowledge of the role of H4R in melanoma proliferation and assess in vivo the therapeutic efficacy of histamine, clozapine and JNJ28610244, an H4R agonist, in a preclinical metastatic model of melanoma. Additionally, we aimed to investigate the combinatorial effect of histamine and gamma radiation on the radiobiological response of melanoma cells.Results indicate that 1205Lu metastatic melanoma cells express H4R and that histamine inhibits proliferation, in part through the stimulation of the H4R, and induces cell senescence and melanogenesis. Daily treatment with H4R agonists (1 mg/kg, sc) exhibited a significant in vivo antitumor effect and importantly, compounds reduced metastatic potential, particularly in the group treated with JNJ28610244, the H4R agonist with higher specificity. H4R is expressed in benign and malignant lesions of melanocytic lineage, highlighting the potential clinical use of histamine and H4R agonists. In addition, histamine increased radiosensitivity of melanoma cells in vitro and in vivo. We conclude that stimulation of H4R by specific ligands may represent a novel therapeutic strategy in those tumors that express this receptor. Furthermore, through increasing radiation-induced response, histamine could improve cancer radiotherapy for the treatment of melanoma.

Gold nanoparticles as dose-enhancement agent for kilovoltage X-ray therapy of melanoma

PURPOSE

Melanoma is mainly treated by surgery and rarely with radiation because of the high radioresistance of this tumor. Nevertheless, radiotherapy is the preferred treatment modality for unresectable lesions and avoiding cosmetic disfigurement caused by surgical excision. This study investigated the therapeutic advantage of gold nanoparticles (AuNPs) for kilovoltage X-ray treatment of melanoma.

MATERIALS AND METHODS

Commercial AuNPs were evaluated for cytotoxicity and cellular internalization. The sensitivity of human skin melanoma cells to 150 and 450 kVp X-ray exposure was assessed in terms of clonogenicity with or without spherical AuNP treatment.

RESULTS

AuNP treatment elicited dose enhancement effect on melanoma cells exposed to kilovoltage X-rays. Treatment with 320 μM 50 nm AuNPs before exposure to 150 kVp X-rays at 2 Gy resulted in clonogenic cell death equivalent to that caused by 4.3 Gy X-rays without AuNP treatment.

CONCLUSION

AuNPs of 50 nm in size can regulate melanoma cells in kilovoltage X-ray treatment by functioning as dose-enhancement agent and thus improving radioresponse of the cells. Melanomas of stages T1-T3 gain therapeutic benefits from 150 kVp X-ray treatment.

A combination of high dose rate (10X FFF/2400 MU/min/10 MV X-rays) and total low dose (0.5 Gy) induces a higher rate of apoptosis in melanoma cells in vitro and superior preservation of normal melanocytes

The aim of this study was to determine the apoptotic effects, toxicity, and radiosensitization of total low dose irradiation delivered at a high dose rate in vitro to melanoma cells, normal human epidermal melanocytes (HEM), or normal human dermal fibroblasts (HDF) and to study the effect of mitochondrial inhibition in combination with radiation to enhance apoptosis in melanoma cells. Cells irradiated using 10X flattening filter-free (FFF) 10 MV X-rays at a dose rate of 400 or 2400 MU/min and a total dose of 0.25–8 Gy were analyzed by cell/colony counting, MitoTracker, MTT, and DNA-damage assays, as well as by quantitative real-time reverse transcriptase PCR in the presence or absence of mitochondrial respiration inhibitors. A dose rate of 2400 MU/min killed on average five-fold more melanoma cells than a dose rate 400 MU/min at a total dose of 0.5 Gy and preserved 80% survival of HEM and 90% survival of HDF. Increased apoptosis at the 2400 MU/min dose rate is mediated by greater DNA damage, reduced cell proliferation, upregulation of apoptotic genes, and downregulation of cell cycle genes. HEM and HDF were relatively unharmed at 2400 MU/min. Radiation induced upregulation of mitochondrial respiration in both normal and cancer cells, and blocking the respiration with inhibitors enhanced apoptosis only in melanoma cells. A high dose rate with a low total dose (2400 MU/min, 0.5 Gy/10X FFF 10 MV X-rays) enhances radiosensitivity of melanoma cells while reducing radiotoxicity toward HEM and HDF. Selective cytotoxicity of melanoma cells is increased by blocking mitochondrial respiration.

Whole Brain Radiotherapy and RRx-001: Two Partial Responses in Radioresistant Melanoma Brain Metastases from a Phase I/II Clinical Trial: A TITE-CRM Phase I/II Clinical Trial

BACKGROUND: Kim et al. report two patients with melanoma metastases to the brain that responded to treatment with RRx-001 and whole brain radiotherapy (WBRT) without neurologic or systemic toxicity in the context of a phase I/II clinical trial. RRx-001 is an reactive oxygen and reactive nitrogen species (ROS/RNS)-dependent systemically nontoxic hypoxic cell radiosensitizer with vascular normalizing properties under investigation in patients with various solid tumors including those with brain metastases. SIGNIFICANCE: Metastatic melanoma to the brain is historically associated with poor outcomes and a median survival of 4 to 5 months. WBRT is a mainstay of treatment for patients with multiple brain metastases, but no significant therapeutic advances for these patients have been described in the literature. To date, candidate radiosensitizing agents have failed to demonstrate a survival benefit in patients with brain metastases, and in particular, no agent has demonstrated improved outcome in patients with metastatic melanoma. Kim et al. report two patients with melanoma metastases to the brain that responded to treatment with novel radiosensitizing agent RRx-001 and WBRT without neurologic or systemic toxicity in the context of a phase I/II clinical trial.

Stereotactic radiosurgery for brain metastases from malignant melanoma

Background:

Surgical resection and stereotactic radiosurgery (SRS) are well-established treatment methods for patients with brain metastases, yet their respective roles in the management of brain metastases remain incompletely defined.

Methods:

To report on the role of SRS in the treatment of patients with brain metastases from malignant melanoma, a retrospective analysis of 381 intracranial melanoma metastases in 103 consecutive patients who underwent SRS between 2005 and 2011 at Beth Israel Deaconess Medical Center was conducted. The Cyberknife^® SRS system was used to treat all patients. Clinical, technical, and radiographic data were recorded at presentation and on follow-up.

Results:

The patient cohort consisted of 40 female (39%) and 63 male (61%) patients with a median age of 57 years. The median overall survival from the time of radiosurgery for the entire patient cohort was 7.6 months. The local control rate at 1-year was 72% for the patients who received surgery followed by SRS and 55% for the entire patient population. Surgery followed by SRS was associated with significantly improved overall survival compared with SRS alone or whole-brain radiation therapy followed by salvage SRS (P < 0.0057).

Conclusions:

Both surgery plus SRS and SRS provide comparable local control. Despite the difference in lesion size in the subgroups who received surgery plus SRS and radiosurgery alone, similar outcomes were achieved in both groups, suggesting that surgical treatment of larger lesions can yield results that are not significantly different from small lesions treated by SRS alone.

Evaluation of (68)Ga- and (177)Lu-DOTA-PEG4-LLP2A for VLA-4-Targeted PET Imaging and Treatment of Metastatic Melanoma

Malignant melanoma is a highly aggressive cancer, and the incidence of this disease is increasing worldwide at an alarming rate. Despite advances in the treatment of melanoma, patients with metastatic disease still have a poor prognosis and low survival rate. New strategies, including targeted radiotherapy, would provide options for patients who become resistant to therapies such as BRAF inhibitors. Very late antigen-4 (VLA-4) is expressed on melanoma tumor cells in higher levels in more aggressive and metastatic disease and may provide an ideal target for drug delivery and targeted radiotherapy. In this study, we evaluated (177)Lu- and (68)Ga-labeled DOTA-PEG4-LLP2A as a VLA-4-targeted radiotherapeutic with a companion PET agent for diagnosis and monitoring metastatic melanoma treatment. DOTA-PEG4-LLP2A was synthesized by solid-phase synthesis. The affinity of (177)Lu- and (68)Ga-labeled DOTA-PEG4-LLP2A to VLA-4 was determined in B16F10 melanoma cells by saturation binding and competitive binding assays, respectively. Biodistribution of the LLP2A conjugates was determined in C57BL/6 mice bearing B16F10 subcutaneous tumors, while PET/CT imaging was performed in subcutaneous and metastatic models. (177)Lu-DOTA-PEG4-LLP2A showed high affinity to VLA-4 with a Kd of 4.1 ± 1.5 nM and demonstrated significant accumulation in the B16F10 melanoma tumor after 4 h (31.5 ± 7.8%ID/g). The tumor/blood ratio of (177)Lu-DOTA-PEG4-LLP2A was highest at 24 h (185 ± 26). PET imaging of metastatic melanoma with (68)Ga-DOTA-PEG4-LLP2A showed high uptake in sites of metastases and correlated with bioluminescence imaging of the tumors. These data demonstrate that (177)Lu-DOTA-PEG4-LLP2A has potential as a targeted therapeutic for treating melanoma as well as other VLA-4-expressing tumors. In addition, (68)Ga-DOTA-PEG4-LLP2A is a readily translatable companion PET tracer for imaging of metastatic melanoma.

Role of radiation therapy as immune activator in the era of modern immunotherapy for metastatic malignant melanoma

Metastatic melanoma is difficult to treat, and often portends a grim prognosis. For patients with cerebral metastases, the prognosis is even more dire. Systemic immunotherapy and targeted agents are emerging as the mainstay of treatment for metastatic melanoma. Although immunotherapy has been shown to prolong relapse-free survival and long-term control of micrometastatic disease, the response rate is suboptimal, prompting the need to optimize and improve therapy. Accumulating evidence suggests that in addition to effective locoregional control, radiation therapy (RT) may induce immune activation and expansion of T lymphocytes recognizing melanocyte-specific antigens including activated cytotoxic T lymphocytes that can potentially kill melanoma cells. In some cases, RT contributes to the clearance of metastatic disease in distant, nonirradiated regions, a bystander phenomenon called the abscopal effect. Here, we evaluate the potential promise of ablative radiation treatment in the era of modern immunotherapy by presenting a patient with metastatic melanoma who remained disease free for over 3 years after an initial diagnosis of advanced metastatic melanoma with brain, subcutaneous tissue, mesenteric, pelvic, and retroperitoneal involvement. The patient failed initial stereotactic radiosurgery, but responded to whole-brain RT in combination with interleukin-2 immunotherapy. Thus, combination RT with immunotherapy may be synergistic by promoting the release and processing of melanoma antigens that can be presented by dendritic cells. This in turn may augment the response to therapies that center on expansion and/or activation of antitumor T cells.

Mucosal melanoma of the nasal cavity and paranasal sinuses

Mucosal melanoma of the nasal cavity and paranasal sinuses is a rare disease, but its incidence appears to be increasing. The mean age at diagnosis is between 65 and 70 years. Unilateral nasal obstruction and epistaxis are the most common presenting complaints. Melanoma arises in the septum or lateral wall of the nasal cavity in the great majority of cases. The histological diagnosis is based on specific immunohistochemical labelling and is usually established at an advanced stage of disease: stage T3 or T4 tumours according to the 7th edition of the American Joint Committee on Cancer (AJCC) classification of tumours. First-line treatment consists of surgery. The place of intranasal endoscopic surgery remains controversial due to the difficulty of controlling surgical margins and should be reserved for experienced teams. Adjuvant radiotherapy is usually performed due to its efficacy on local and regional disease control. Five-year overall survival of mucosal melanoma of the nasal cavity and paranasal sinuses in the most recent series does not exceed 40%. Local recurrence is observed in about 50% of cases and metastatic disease is common. The quality of initial tumour resection with negative surgical margins is the most important prognostic factor for tumours confined to the nasal cavity. Hopes for improvement of survival are based on early diagnosis, progress in radiotherapy techniques and cell and gene therapy that are currently under evaluation.

On the application of Nafion membrane for the preparation of (90)Y skin patches, quality control, and biological evaluation for treatment of superficial tumors

This article describes the preparation, quality control, and biological evaluation of (90)Y-skin patches based on Nafion(®) membrane as a viable treatment modality for superficial skin tumors such as melanoma. To arrive at the conditions for optimum uptake of (90)Y on the membrane, influence of various experimental parameters, such as pH of the feed solution, inactive yttrium carrier concentration, reaction volume, contact time, and temperature, was systematically investigated. Under the optimized conditions, >95% of the (90)Y activity (37-185 MBq) could be incorporated in the Nafion membranes to prepare (90)Y-skin patches. Quality control tests were carried out to ensure nonleachability, uniform distribution of activity, and stability of the (90)Y-patches. Mice bearing transplanted melanoma tumors that were treated with two doses of 74 MBq (90)Y-Nafion membrane sources showed complete tumor regression. Histopathological examination of the treated area showed absence of tumor. The results of the study indicate the potential of (90)Y-Nafion membrane sources for treatment of superficial skin tumors.

Abscopal effects of radiation therapy: a clinical review for the radiobiologist

An "abscopal" effect occurs when localized irradiation perturbs the organism as a whole, with consequences that can be either beneficial or detrimental. Mechanistic explanations of this effect are challenging. From the oncologist's perspective, the term refers to distant tumor regression after localized irradiation. On the other hand, from a biologist's point of view, abscopal effects include induction of genomic instability, cell death, and oncogenic transformation in normal tissues. This conceptual dichotomy is explored in this review, with a focus on clinically documented cases of anti-tumor abscopal effects and abscopal effects in normal tissues. This review also outlines several suggested mechanisms for abscopal effects.

In vivo efficacy of melanoma internal radionuclide therapy with a 131I-labelled melanin-targeting heteroarylcarboxamide molecule

The development of alternative therapies for melanoma treatment is of great interest as long-term tumour regression is not achieved with new targeted chemotherapies on selected patients. We previously demonstrated that radioiodinated heteroarylcarboxamide ([131I]ICF01012) induced a strong anti-tumoural effect by inhibiting both primary tumour growth and dissemination process in a B16BL6 melanoma model. In our study, we show that a single injection of [131I]ICF01012 (ranging from 14.8 to 22.2 MBq) was effective and associated with low and transient haematological toxicity. Concerning pigmented organs, cutaneous melanocytes and skin were undamaged. In 30% of treated animals, no histological alteration of retina was observed, and in the remaining 70%, damages were restricted to the optic nerve area. Using the Medical Internal Radiation Dose methodology, we determined that the absorbed dose in major organs is very low (<4 Gy) and that a delivery of 30 Gy to the tumour is sufficient for an effective anti-tumoural response. Molecular analyses of treated tumours showed a strong radiobiological effect with a decrease in proliferation, survival and pro-angiogenic-related markers and an increase in tumour suppressor gene expression, melanogenesis and anti-angiogenic markers. All these features are in accordance with a tumour cell death mechanism that mainly occurs by mitotic catastrophe and provide a better understanding of in vivo anti-tumoural effects of [131I] radionuclide. Our findings raise [131I]ICF01012 a good candidate for disseminated melanoma treatment and strongly support transfer of [131I]ICF01012 to clinical trial.

Development of gadolinium based nanoparticles having an affinity towards melanin

Small Rigid Platforms (SRPs) are sub-5 nanometre gadolinium based nanoparticles that have been developed for multimodal imaging and theranostic applications. They are composed of a polysiloxane network surrounded by gadolinium chelates. A covalent coupling with quinoxaline derivatives has been performed. Such derivatives have proven their affinity for melanin frequently expressed in primary melanoma cases. Three different quinoxaline derivatives have been synthesised and coupled to the nanoparticles. The affinity of the grafted nanoparticles for melanin has then been shown in vitro by surface plasmon resonance on a homemade melanin grafted gold chip.

Sonography of the primary cutaneous melanoma: a review

The diagnosis and management of primary cutaneous melanoma have traditionally relied on clinical and histological characteristics. Nevertheless, in recent years there has been a significant growth in the usage of ultrasound for studying the cutaneous layers. Thus, the present paper focuses on the primary lesion, its sonographic characteristics, the potential benefits of early imaging, and the new developments on the ultrasound field applied to cutaneous melanoma.