Radiotherapy and immunotherapy: Can this combination change the prognosis of patients with melanoma brain metastases?

Anti-PD-1/PD-L1 inhibitor therapy for melanoma brain metastases: a systematic review and meta-analysis

Melanoma brain metastases present a major challenge in cancer treatment and reduce overall survival despite advances in managing primary melanoma. Immune checkpoint inhibitors (ICIs) that target PD-1/PD-L1 pathways have shown promise in treating advanced melanoma, but their efficacy for melanoma brain metastases is debated. This systematic review and meta-analysis summarize evidence on anti-PD-1/PD-L1 inhibitors for melanoma brain metastases. This systematic review and meta-analysis followed PRISMA guidelines. PICO criteria targeted melanoma brain metastasis patients treated with PD-1/PD-L1 inhibitors, assessing overall survival, progression-free survival, and complications. Inclusion criteria were English studies on humans using PD-1/PD-L1 inhibitors for melanoma brain metastases with > 10 patients. A total of 22 trials involving 1523 melanoma brain metastase patients treated with anti-PD-1/PD-L1 inhibitors were thoroughly analyzed. Our findings show the 6-month OS rate of 0.75 [95%CI:0.67-0.84], the 6-months PFS rate of 0.42 [95%CI:0.31-0.52], the 1-year OS rate of 0.63 [95%CI:0.52-0.74], the 1-year PFS rate was 0.45 [95%CI:0.32-0.58], the 18-months OS rate of 0.52 [95%CI:0.37-0.67], the 2-year OS rate of 50% [95% CI: (34%-65%)], the 2 year PFS rate of 0.36 (95%CI:0.23-0.50), the 3-year OS rate of 0.42 (95%CI:0.17-0.67), the 4-year PFS rate of 0.35 [95%CI:0.08-0.61], the 4-year OS rate of 0.29 [95%CI:0.01-0.56], the 5-year OS rate of 0.29 (95%CI:0.09-0.50), and the 5-year PFS rate of 0.11 (95%CI:0.03-0.19). The combined disease stability rate was 0.13 [95%CI:0.05-0.20], the progressive disease rate was 0.49 [95%CI:0.37-0.62], the partial response rate was 0.14 [95%CI:0.07-0.20], the object response rate was 0.35 [95%CI:0.24-0.46], and the complete response rate was 0.22 [95%CI:0.12-0.32]. In conclusion, our meta-analysis provides compelling evidence supporting the efficacy of PD-1/PD-L1 inhibitors in patients with melanoma brain tumors, as evidenced by favorable survival outcomes and disease control rates.

Inflammatory parameters in NSCLC with driver mutation

Aim: The tumor microenvironment of NSCLC with driver mutations, such as EGFR, ALK and ROS, is less inflammatory. Materials & methods: This retrospective study included 38 patients with NSCLC driver mutations. The relationship between clinical and inflammatory markers concerning progression-free survival and overall survival was analyzed based on Kaplan-Meier curves. Results: The mean age of the patients was 59.8 ± 11.9. Progression-free survival and overall survival were significantly longer in patients under 65 years of age and with low neutrophil-lymphocyte ratio, low systemic immune-inflammation index and high lymphocyte count (p < 0.05). Conclusion: Unlike tumor biology, peripheral inflammatory parameters, such as neutrophil-lymphocyte ratio, systemic immune-inflammation index and lymphocyte count may be associated with survival in NSCLC patients with driver mutations.

A modified melanoma-molGPA scoring model: assessment of survival after and efficacy of different radiotherapy modalities in patients with melanoma brain metastases

PURPOSE

Patients with malignant melanoma brain metastases (MBMs) have poor prognoses. For MBMs, the Melanoma-molGPA is the most widely used predictive score, but its predictive value remains uncertain in patients fully treated with radiotherapy. We identified MBMs prognostic factors and modified the prognostic scoring model.

METHODS

We retrospectively analyzed patients diagnosed with MBMs between December 2010 and November 2021 for prognostic factors influencing overall survival (OS) by univariate and multivariate analyses. Nomogram plots were based on Cox regression modeling. We evaluated overall survival (OS) using Kaplan-Meier survival curves and log-rank tests.

RESULTS

The median OS (mOS) was 7.9 months. On multivariate analysis, BRAF mutation status (p < 0.001), number of brain metastases (BM) (p < 0.001), presence of liver metastases (p < 0.001), brain metastases with a midline shift (p = 0.003), Karnofsky Performance Score (p = 0.02), and lymphocyte-to-monocyte ratio (p < 0.0001) were independent OS predictors. These were incorporated into a modified risk-stratification model. Overall, whole-brain radiotherapy (WBRT) did not significantly affect mOS (mOS, 6.89 vs. 8.83 months; p = 0.07). After risk stratification using our model, WBRT resulted in no significant survival benefit in the low-risk group (mOS 10.07 vs. 13.1 months; p = 0.71) but significantly worse prognosis in the high-risk group (mOS, 2.37 vs. 6.92 months; p = 0.026).

CONCLUSION

We propose a modified model that accurately distinguishes the prognosis of patients with MBMs and guides decision-making for radiotherapy. Based on this novel model, WBRT should be cautiously selected for high-risk patients.

The role of stereotactic radiotherapy in addition to immunotherapy in the management of melanoma brain metastases: results of a systematic review

Aim of this study was to systematically review the literature to assess efficacy and safety of stereotactic radiotherapy (SRT) in combination with immunotherapy for the treatment of melanoma brain metastases (MBM). The literature was searched using PubMed, Scopus, and Embase. Studies comparing SRT plus immunotherapy versus SRT or immunotherapy alone were deemed eligible for inclusion. Two studies showed improved overall survival after SRT plus immunotherapy in melanoma cancer patients with brain metastases. Three studies reported data on LC and DFS showing as SRT plus immunotherapy did not improve local control and DFS rates. G3-G4 toxicity was reported in only one study (20% in the SRT plus immunotherapy group versus 23% in the immunotherapy group). Despite SRT plus concurrent immunotherapy seems associated with possible survival advantage and low ≥ G3 late toxicity rates, the quality of evidence is very low. Therefore, in patients with brain metastases from melanoma, SRT plus immunotherapy should be evaluated on an individual basis after discussion by a multidisciplinary team.

Melanoma Brain Metastases: An Update on the Use of Immune Checkpoint Inhibitors and Molecularly Targeted Agents

Brain metastases from melanoma are no longer uniformly associated with dismal outcomes. Impressive tumor tissue-based (craniotomy) translational research has consistently shown that distinct patient subgroups may have a favorable prognosis. This review provides a historical overview of the standard-of-care treatments until the early 2010s. It subsequently summarizes more recent advances in understanding the biology of melanoma brain metastases (MBMs) and treating patients with MBMs, mainly focusing upon prospective clinical trials of BRAF/MEK and PD-1/CTLA-4 inhibitors in patients with previously untreated MBMs. These additional systemic treatments have provided effective complementary treatment approaches and/or alternatives to radiation and craniotomy. The current role of radiation therapy, especially in conjunction with systemic therapies, is also discussed through the lens of various retrospective studies. The combined efficacy of systemic treatments with radiation has improved overall survival over the last 10 years and has sparked considerable research interest regarding optimal dosing and sequencing of radiation treatments with systemic treatments. Finally, the review describes ongoing clinical trials in patients with MBMs.

State of the Art in Combination Immuno/Radiotherapy for Brain Metastases: Systematic Review and Meta-Analysis

OBJECTIVES

Common origins for brain metastases (BMs) are melanoma, lung, breast, and renal cell cancers. BMs account for a large share of morbidity and mortality caused by these cancers. The advent of new immunotherapeutic treatments has made a revolution in the treatment of cancer patients and particularly, as a new concept, if it is combined with radiotherapy, may lead to considerably longer survival. This systematic review and meta-analysis aimed to evaluate the survival rate and toxicities of such a combination in brain metastases.

METHODS

To perform a systematic review of the literature until January 2021 using electronic databases such as PubMed, Cochrane Library, and Embase; the Newcastle-Ottawa Scale was used to evaluate the quality of cohort studies. For data extraction, two reviewers extracted the data blindly and independently. Hazard ratio with 95% confidence interval (CI), fixed-effect model, and inverse-variance method was calculated. The meta-analysis has been evaluated with the statistical software Stata/MP v.16 (The fastest version of Stata).

RESULTS

In the first step, 494 studies were selected to review the abstracts, in the second step, the full texts of 86 studies were reviewed. Finally, 28 studies were selected consisting of 1465 patients. The addition of IT to RT in the treatment of brain metastasis from melanoma and non-small-cell lung carcinoma was associated with a 39% reduction in mortality rate and has prolonged overall survival, with an acceptable toxicity profile. The addition of IT to RT compared with RT alone has a hazard ratio of 0.39(95% CI 0.34-0.44).

CONCLUSIONS

A combination of immuno/radiotherapy (IR) for the treatment of patients with BMs from melanoma and non-small-cell lung carcinoma has prolonged overall survival and reduced mortality rate, with acceptable toxicity. In terms of timing, RT seems to have the best effect on the result when performed before or simultaneously with immunotherapy.

Genomic and Transcriptomic Profiling of Brain Metastases

Simple Summary

Brain metastases (BM) are the most common brain tumors in adults and are the main cause of cancer-associated death. Omics analysis of BM will allow for a better understanding of metastatic progression, prognosis and therapeutic targeting. In this study, BM samples underwent comprehensive molecular profiling with genomics and transcriptomics. Mutational signatures suggested that most mutations were gained prior to metastasis. A novel copy number event centered around the MCL1 gene was found in 75% of all samples. Transcriptomics revealed that melanoma BM formed a distinct cluster in comparison to other subtypes. Poor survival correlated to self-identified black race and absence of radiation treatment but not molecular profiles. These data identify potential new drivers of brain metastatic progression, implicate that melanoma BM are distinctive and likely responsive to unique therapies, and further investigation of sociodemographic and clinical features are needed in BM cohorts.

Abstract

Brain metastases (BM) are the most common brain tumors in adults occurring in up to 40% of all cancer patients. Multi-omics approaches allow for understanding molecular mechanisms and identification of markers with prognostic significance. In this study, we profile 130 BM using genomics and transcriptomics and correlate molecular characteristics to clinical parameters. The most common tumor origins for BM were lung (40%) followed by melanoma (21%) and breast (15%). Melanoma and lung BMs contained more deleterious mutations than other subtypes (p < 0.001). Mutational signatures suggested that the bulk of the mutations were gained before metastasis. A novel copy number event centered around the MCL1 gene was found in 75% of all samples, suggesting a broader role in promoting metastasis. Unsupervised hierarchical cluster analysis of transcriptional signatures available in 65 samples based on the hallmarks of cancer revealed four distinct clusters. Melanoma samples formed a distinctive cluster in comparison to other BM subtypes. Characteristics of molecular profiles did not correlate with survival. However, patients with self-identified black race or those who did not receive radiation correlated with poor survival. These data identify potential new drivers of brain metastatic progression. Our data also suggest further investigation of sociodemographic and clinical features is needed in BM cohorts.

Melanoma brain metastases - Interdisciplinary management recommendations 2020

Melanoma brain metastases (MBM) are common and associated with a particularly poor prognosis; they directly cause death in 60-70% of melanoma patients. In the past, systemic treatments have shown response rates around 5%, whole brain radiation as standard of care has achieved a median overall survival of approximately three months. Recently, the combination of immune checkpoint inhibitors and combinations of MAP-kinase inhibitors both have shown very promising response rates of up to 55% and 58%, respectively, and improved survival. However, current clinical evidence is based on multi-cohort studies only, as prospectively randomized trials have been carried out rarely in MBM, independently whether investigating systemic therapy, radiotherapy or surgical techniques. Here, an interdisciplinary expert team reviewed the outcome of prospectively conducted clinical studies in MBM, identified evidence gaps and provided recommendations for the diagnosis, treatment, outcome evaluation and monitoring of MBM patients. The recommendations refer to four distinct scenarios: patients (i) with 'brain-only' disease, (ii) with oligometastatic asymptomatic intra- and extracranial disease, (iii) with multiple asymptomatic metastases, and (iv) with multiple symptomatic MBM or leptomeningeal disease. Changes in current management recommendations comprise the use of immunotherapy - preferably combined anti-CTLA-4/PD-1-immunotherapy - in asymptomatic MBM minus/plus stereotactic radiosurgery which remains the mainstay of local brain therapy being safe and effective. Adjuvant whole-brain radiotherapy provides no clinical benefit in oligometastatic MBM. Among the systemic therapies, combined MAPK-kinase inhibition provides, in BRAF^V600-mutated patients with rapidly progressing or/and symptomatic MBM, an alternative to combined immunotherapy.

Pure abscopal effect of radiotherapy in a salivary gland carcinoma: Case report, literature review, and a search for new approaches

We report the case of an 84-year-old woman with poorly differentiated non-small cell carcinoma of the right parotid who presented with headache, was found to have a primary right parotid gland cancer as well as metastatic disease, and underwent palliative radiotherapy to the primary site. The patient received no chemotherapy or immunotherapy, but both the primary site and several non-irradiated foci in the lungs regressed or completely resolved. The patient remained free of disease for about one year before progression. The case is a rare instance of abscopal regression of metastatic disease in the absence of pharmacologic immunomodulation. A literature review surveys the history of the abscopal effect of radiation therapy, attempts to understand the mechanisms of its successes and failures, and points to new approaches that can inform and improve the outcomes of radioimmunotherapy.

Aquaporin-1 Protein Expression of the Primary Tumor May Predict Cerebral Progression of Cutaneous Melanoma

Brain metastasis is a frequent complication of the progression of malignant melanoma. In a previous study aquaporin 1 (AQP1) protein expression was found to be associated with increased mortality and decreased progression free survival in cutaneous melanoma. To explore further the potential of this marker we studied the AQP1 protein expression in 67 metastatic melanoma patients using immunohistochemistry. Primary tumor samples were acquired from patients with brain (BR) (n = 44) and extra-cranial (EC) (n = 23) metastases, while brain metastatic samples were collected during neurosurgical resection (n = 5). Patients with brain metastases had shorter overall survival (p = 0.02) and significantly higher AQP1 expression in the primary tumors (median H-score = 250 vs. 140, p = 0.044) as compared to patients of the EC metastasis group. AQP1 expression was found to be significantly lower in the brain metastases compared to the corresponding primary tumors (median H-score = 35 vs. 300 p = 0.01). However, in brain metastases AQP1 expression was heterogenous, AQP1 protein was more abundant in the melanoma cells far away from the capillaries as compared to tumor cells adjacent to vessels indicating a hypoxia-driven expression of AQP1. We suggest that AQP1 expression could well be a prognostic marker of brain metastatic potential of human cutaneous melanoma.

Integration of stereotactic radiosurgery or whole brain radiation therapy with immunotherapy for treatment of brain metastases

The prognosis of brain metastases (BM) is traditionally poor. BM are mainly treated by local radiotherapy, including stereotactic radiosurgery (SRS) or whole brain radiation therapy (WBRT). Recently, immunotherapy (i.e., immune checkpoint inhibitors, ICI) has demonstrated a survival advantage in multiple malignancies commonly associated with BM. Individually, radiotherapy and ICI both treat BM efficiently; hence, their combination seems logical. In this review, we summarize the existing preclinical and clinical evidence that supports the applicability of radiotherapy as a sensitizer of ICI for BM. Further, we discuss the optimal timing at which radiotherapy and ICI should be administered and review the safety of the combination therapy. Data from a few clinical studies suggest that combining SRS or WBRT with ICI simultaneously rather than consecutively potentially enhances brain abscopal-like responses and survival. However, there is a lack of conclusion about the definition of "simultaneous"; the cumulative toxic effect of the combined therapies also requires further study. Thus, ongoing and planned prospective trials are needed to further explore and validate the effect, safety, and optimal timing of the combination of immunotherapy with radiotherapy for patients with BM.

Combination of radiotherapy and immunotherapy for brain metastases: A systematic review and meta-analysis

Radiotherapy (RT) represents a mainstay in the treatment of brain metastases (BMs) from solid tumors. Immunotherapy (IT) has improved survival of metastatic cancer patients across many tumor types. The combination of RT and IT for the treatment of BMs has a strong rationale, but data on efficacy and safety of this combination is still limited. A systematic search of PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE was conducted. 33 studies were included for a total of 1520 patients, most of them with melanoma (87%). Median pooled OS was 15.9 months (95%CI 13.9-18.1). One- and 2-year OS rates were 55.2% (95% CI 49.3-60.9) and 35.7% (95% CI 30.4-41.3), respectively. Addition of IT to RT was associated with improved OS (HR = 0.54, 95%CI 0.44-0.67; P < 0.001). For patients with BMs from solid tumors, addition of concurrent IT to brain RT is able to increase survival and provide long term control.

Cognitive effects of stereotactic radiosurgery in adult patients with brain metastases: A systematic review

PURPOSE

Stereotactic radiation surgery (SRS) is increasingly applied in patients with brain metastases (BM) and is expected to have fewer adverse effects on cognitive functioning than whole brain radiation therapy (WBRT). Patients with BM are often confronted with a relatively short life expectancy, and the prevention or delay of cognitive decline to maintain quality of life is a clinically and highly relevant treatment goal. This review systematically and specifically evaluates the current literature on the cognitive effects of SRS in patients with BM.

METHODS AND MATERIALS

Published trials on SRS alone or in combination with WBRT, including objective assessment of cognitive functioning, were identified through a systematic search of the PubMed database up to March 2018.

RESULTS

Of the 241 records screened, 14 studies matched the selection criteria: 2 pilot studies, 7 single-group/observational trials (1 study update), and 5 randomized trials (1 secondary analysis).

CONCLUSIONS

In general, the results show little to no objective cognitive decline up to 4 months after SRS compared with WBRT. However, most trials suffered from methodologic limitations that hindered reliable conclusions. Most importantly, few studies investigated the specific cognitive effects of SRS alone or versus WBRT. Furthermore, disentangling the cognitive effects of SRS from the effects of the disease itself and from the effects of other treatments remains very difficult. By presenting this comprehensive review, we aim to encourage researchers to probe deeper into this area and to do so in a standardized and methodologically optimal manner. The ultimate objective of this line of research is to inform both doctors and patients more precisely about the cognitive effects they can expect from treatment. This study is expected to improve the quality of decision-making and maximize clinical outcomes for each individual patient.

In Vivo Irradiation of Mice Induces Activation of Dendritic Cells

It is becoming clear that ionizing radiation positively influences certain immune parameters, which opens the possibility for combining radio- and immunotherapies in cancer treatment. The presence of functionally competent dendritic cells (DCs) is crucial in mounting a successful antitumor immune response. While it has been shown that DCs are relatively radioresistant, few and contradictory data are available on how ionizing radiation alters the functional integrity of these cells. Therefore, our objective was to investigate the effect of whole-body irradiation on the function of splenic DCs. C57Bl/6 mice were irradiated with 0.1, 0.25, and 2 Gy X-rays and changes in the phenotype of splenic DCs were compared to unirradiated controls. An increase was seen in DC surface markers influencing DC-T cell interactions. In vivo cytokine production was determined by direct intracellular cytokine staining. Irradiation with 2 Gy induced a 1.6-fold increase in IL-1α production, while the combination of irradiation and lipopolysaccharide (LPS) treatment induced a 3.9-fold increase, indicating a strong synergism between irradiation and LPS stimulation. Interaction of DCs with effector and regulatory T cells was investigated in a mixed lymphocyte reaction. While DCs from control animals induced stronger proliferation of regulatory T cells, DCs from animals irradiated with 2 Gy induced stronger proliferation of effector T cells. Antigen uptake and presentation was investigated by measuring the capacity of DCs to internalize and present ovalbumine (OVA)-derived peptides on their major histocompatibility complex (MHCI) molecules. Irradiation with 2 Gy did not influence antigen uptake or presentation, while low doses stimulated antigen uptake and reduced the level of antigen presentation. In conclusion, high-dose in vivo irradiation induced increased expression of T cell costimulatory markers, enhanced production of proinflammatory cytokines and a stronger stimulation of effector T cell proliferation than that of regulatory T cells. However, it did not influence DC antigen uptake or presentation. On the other hand, low-dose irradiation increased antigen uptake and lowered antigen presentation of DCs, indicating that low- and high-dose irradiation act on different pathways in DCs.

Validation of the Chowdhury overall survival score in patients with melanoma brain metastasis treated with Gamma Knife Radiosurgery

Melanoma brain metastases (MBM) are common in patients with stage IV disease. For Gamma Knife radiosurgery (GKRS) on MBM, risk scores such as RPA and melanoma-GPA aid to identify prognostic subgroups. This study aimed to validate the overall survival (OS) risk score developed by Chowdhury et al. in our center's patient cohort. A total of 104 MBM patients were treated with GKRS between 1/1/2002 and 31/12/2014 in our institution. Patients were categorized according to RPA, melanoma-GPA and Chowdhury OS score. The Kaplan-Meier method was used to estimate overall survival, and predicted survival probabilities were calculated for calibration. Cox proportional hazards regressions were performed to identify additional risk factors. Overall, median follow-up time was 80 months, while median OS (mOS) after GKRS was 6 months. Stratified according to the Chowdhury OS score, mOS in the high, medium and low risk group was 3.4, 7.1, and 10.0 months, respectively. The addition of other patient or disease characteristics to the Chowdhury OS model did not improve its performance. The C-index of the melanoma-GPA was 0.46 while the Chowdhury OS had an index of 0.67. In comparison with the RPA and melanoma-GPA, the Chowdhury OS score more accurately distinguished between separate risk groups among patients with MBM treated with GKRS. Contrary to the original study by Chowdhury, follow-up time was sufficient here for the low-risk group to reach the mOS time of 10 months.

Recent advances in the biology and treatment of brain metastases of non-small cell lung cancer: summary of a multidisciplinary roundtable discussion

This article is the result of a round table discussion held at the European Lung Cancer Conference (ELCC) in Geneva in May 2017. Its purpose is to explore and discuss the advances in the knowledge about the biology and treatment of brain metastases originating from non-small cell lung cancer. The authors propose a series of recommendations for research and treatment within the discussed context.

SRS in Combination With Ipilimumab: A Promising New Dimension for Treating Melanoma Brain Metastases

Stereotactic radiosurgery provides effective local control, but high recurrence rate are observed while ipilimumab have shown promising improvements in survival in the treatment of melanoma brain metastases. This meta-analysis was done to review the clinical evidence regarding the combination of stereotactic radiosurgery and ipilimumab in the treatment of brain metastases from melanoma. Comprehensive research of the electronic databases (PubMed and Cochrane Library) was carried out in April 2017. Different combination of MESH headings and words were used. Review Manager was used to analyze the outcome data of interest. According to heterogeneity, fixed effects model or random effects model was adapted. Six retrospective studies comparing stereotactic radiosurgery plus ipilimumab with stereotactic radiosurgery alone were found. Total of 411 participants were included in this meta-analysis. Of that, 128 patients had received stereotactic radiosurgery + ipilimumab, while 283 patients had received stereotactic radiosurgery only. Stereotactic radiosurgery plus ipilimumab significantly improved survival when compared to stereotactic radiosurgery alone (hazard ratio: 0.74 [95% confidence interval: 0.56-0.99, P = .04]), with no significant increase in the incidence of adverse events (odds ratio 0.57 [95% confidence interval: 0.28-1.17, P = .12]). Stereotactic radiosurgery with ipilimumab is safe and effective treatment option and can be recommended for the treatment of brain metastases in patients with melanoma.

Cancer Immunotherapy Getting Brainy: Visualizing the Distinctive CNS Metastatic Niche to Illuminate Therapeutic Resistance

The advent of cancer immunotherapy (CIT) and its success in treating primary and metastatic cancer may offer substantially improved outcomes for patients. Despite recent advancements, many malignancies remain resistant to CIT, among which are brain metastases, a particularly virulent disease with no apparent cure. The immunologically unique niche of the brain has prompted compelling new questions in immuno-oncology such as the effects of tissue-specific differences in immune response, heterogeneity between primary tumors and distant metastases, and the role of spatiotemporal dynamics in shaping an effective anti-tumor immune response. Current methods to examine the immunobiology of metastases in the brain are constrained by tissue processing methods that limit spatial data collection, omit dynamic information, and cannot recapitulate the heterogeneity of the tumor microenvironment. In the current review, we describe how high-resolution, live imaging tools, particularly intravital microscopy (IVM), are instrumental in answering these questions. IVM of pre-clinical cancer models enables short- and long-term observations of critical immunobiology and metastatic growth phenomena to potentially generate revolutionary insights into the spatiotemporal dynamics of brain metastasis, interactions of CIT with immune elements therein, and influence of chemo- and radiotherapy. We describe the utility of IVM to study brain metastasis in mice by tracking the migration and growth of fluorescently-labeled cells, including cancer cells and immune subsets, while monitoring the physical environment within optical windows using imaging dyes and other signal generation mechanisms to illuminate angiogenesis, hypoxia, and/or CIT drug expression within the metastatic niche. Our review summarizes the current knowledge regarding brain metastases and the immune milieu, presents the current status of CIT and its prospects in targeting brain metastases to circumvent therapeutic resistance, and proposes avenues to utilize IVM to study CIT drug delivery and therapeutic efficacy in preclinical models that will ultimately facilitate novel drug discovery and innovative combination therapies.

EGFR mutation correlates with uninflamed phenotype and weak immunogenicity, causing impaired response to PD-1 blockade in non-small cell lung cancer

Patients with EGFR mutations showed unfavorable response to programmed cell death-1 (PD-1) blockade immunotherapy in non-small cell lung cancer (NSCLC). Yet the underlying association between EGFR mutation and immune resistance remains largely unclear. We performed an integrated analysis of PD-ligand 1(PD-L1)/CD8 expression and mutation profile based on the repository database and resected early-stage NSCLC in Guangdong Lung Cancer Institute (GLCI). Meanwhile, 2 pool-analyses were set to clarify the correlation between EGFR mutation and PD-L1 expression, and the association of EGFR status with response to anti-PD-1/L1 therapy. Pool-analysis of 15 public studies suggested that patients with EGFR mutations had decreased PD-L1 expression (odds ratio: 1.79, 95% CI: 1.10-2.93; P = 0.02). Analysis of The Cancer Genome Atlas (TCGA) and the GCLI cohort confirmed the inverse correlation between EGFR mutation and PD-L1 expression. Furthermore, patients with EGFR mutation showed a lack of T-cell infiltration and shrinking proportion of PD-L1⁺/CD8⁺ TIL (P = 0.034). Importantly, patients with EGFR mutations, especially the sensitive subtype, showed a significantly decreased mutation burden, based on analysis of the discovery and validation sets. Finally, a pool-analysis of 4 randomized control trials confirmed that patients with EGFR mutation did not benefit from PD-1/L1 inhibitors (Hazard ratio [HR] = 1.09, P = 0.51) while patients with EGFR wild-type did (HR = 0.73, P < 0.00001). This study provided evidence of a correlation between EGFR mutations and an uninflamed tumor microenvironment with immunological tolerance and weak immunogenicity, which caused an inferior response to PD-1 blockade in NSCLCs.

Survival Patterns of 5750 Stereotactic Radiosurgery-Treated Patients with Brain Metastasis as a Function of the Number of Lesions

BACKGROUND

The number of brain metastases (BMs) plays an important role in the decision between stereotactic radiosurgery (SRS) and whole-brain radiation therapy.

METHODS

We analyzed the survival of 5750 SRS-treated patients with BM as a function of BM number. Survival analyses were performed with Kaplan-Meier analysis as well as univariate and multivariate Cox proportional hazards models.

RESULTS

Patients with BMs were first categorized as those with 1, 2-4, and 5-10 BMs based on the scheme proposed by Yamamoto et al. (Lancet Oncology 2014). Median overall survival for patients with 1 BM was superior to those with 2-4 BMs (7.1 months vs. 6.4 months, P = 0.009), and survival of patients with 2-4 BMs did not differ from those with 5-10 BMs (6.4 months vs. 6.3 months, P = 0.170). The median survival of patients with >10 BMs was lower than those with 2-10 BMs (6.3 months vs. 5.5 months, P = 0.025). In a multivariate model that accounted for age, Karnofsky Performance Score, systemic disease status, tumor histology, and cumulative intracranial tumor volume, we observed a ∼10% increase in hazard of death when comparing patients with 1 versus 2-10 BMs (P < 0.001) or 10 versus >10 BMs (P < 0.001). When BM number was modeled as a continuous variable rather than using the classification by Yamamoto et al., we observed a step-wise 4% increase in the hazard of death for every increment of 6-7 BM (P < 0.001).

CONCLUSIONS

The contribution of BM number to overall survival is modest and should be considered as one of the many variables considered in the decision between SRS and whole-brain radiation therapy.

Targeted Therapies for Melanoma Brain Metastases

Brain metastases are a major clinical challenge occurring in up to 60% of patients suffering from metastatic melanoma. They cause significant clinical symptoms and impair the overall survival prognosis. The introduction of targeted therapies including BRAF and MEK inhibitors as well as CTLA-4 and PD-1 axis targeting immune checkpoint inhibitors have dramatically improved the treatment and prognosis of patients with extracranial metastatic melanoma. Although, similar response rates for extra- and intracranial metastases have been reported, only few data from brain metastasis specific trails are available so far. The following review will provide an overview on the currently available data on targeted therapies, remaining questions and the most important side effects in the special clinical situation of melanoma brain metastases.

Successes and failures: what did we learn from recent first-line treatment immunotherapy trials in non-small cell lung cancer?

The immune checkpoint inhibitors have significantly modified the therapeutic landscape of advanced non-small cell lung cancer in second-line and, more recently, first-line settings. Because of the superior outcome with pembrolizumab as an upfront strategy, PD-L1 status should now be considered a new reflex biomarker for guiding first-line treatment in patients with advanced non-small cell lung cancer. Improved responses have also been reported with the combination of immune checkpoint inhibitors and chemotherapy as the first-line treatment; however, this strategy has not yet been validated by phase III trial data and its interplay with PD-L1 status still requires clarification.In this manuscript we review the contradictory results of recent phase III trials with immune checkpoint inhibitors in the first-line setting, the potential reasons for discrepancies, and some of the remaining open questions related to the positioning of immune checkpoint inhibitors in the first-line setting of non-small cell lung cancer.

Pathological characteristics of spine metastases treated with high-dose single-fraction stereotactic radiosurgery

OBJECTIVE Spine radiosurgery is increasingly being used to treat spinal metastases. As patients are living longer because of the increasing efficacy of systemic agents, appropriate follow-up and posttreatment management for these patients is critical. Tumor progression after spine radiosurgery is rare; however, vertebral compression fractures are recognized as a more common posttreatment effect. The use of radiographic imaging alone posttreatment may makeit difficult to distinguish tumor progression from postradiation changes such as fibrosis. This is the largest series from a prospective database in which the authors examine histopathology of samples obtained from patients who underwent surgical intervention for presumed tumor progression or mechanical pain secondary to compression fracture. The majority of patients had tumor ablation and resulting fibrosis rather than tumor progression. The aim of this study was to evaluate tumor histopathology and characteristics of patients who underwent pathological sampling because of radiographic tumor progression, fibrosis, or collapsed vertebrae after receiving high-dose single-fraction stereotactic radiosurgery. METHODS Between January 2005 and January 2014, a total of 582 patients were treated with linear accelerator-based single-fraction (18-24 Gy) stereotactic radiosurgery. The authors retrospectively identified 30 patients (5.1%) who underwent surgical intervention for 32 lesions with vertebral cement augmentation for either mechanical pain or instability secondary to vertebral compression fracture (n = 17) or instrumentation (n = 15) for radiographic tumor progression. Radiation and surgical treatment, histopathology, and long-term outcomes were reviewed. Survival and time to recurrence were calculated using the Kaplan-Meier method. RESULTS The mean age at the time of radiosurgery was 59 years (range 36-80 years). The initial pathological diagnoses were obtained for all patients and primarily included radioresistant tumor types, including renal cell carcinoma in 7 (22%), melanoma in 6 (19%), lung carcinoma in 4 (12%), and sarcoma in 3 (9%). The median time to surgical intervention was 24.7 months (range 1.6-50.8 months). The median follow-up and overall survival for all patients were 42.5 months and 41 months (overall survival range 7-86 months), respectively. The majority of assessed lesions showed no evidence of tumor on pathological review (25 of 32, 78%), while a minority of lesions revealed residual tumor (7 of 32, 22%). The median survival for patients after tumor recurrence was 5 months (range 2-70 months). CONCLUSIONS High-dose single-fraction radiosurgery is tumor ablative in the majority of instances. In a minority of cases, tumor persists and salvage treatments should be considered.

Stereotactic Radiosurgery for Melanoma Brain Metastases: A Comprehensive Clinical Case Series

BACKGROUND

Melanoma has high propensity to metastasize to the brain. With recent gains in improving patient survival, stereotactic radiosurgery (SRS) may offer an effective and less neurotoxic alternative to whole-brain radiation. In the study, we report on the safety and efficacy of SRS in treating melanoma brain metastases in 87 patients.

METHODS

This retrospective multicenter study examined 87 patients with 309 metastases who underwent single-dose or multifractionated SRS for treatment of intracranial metastases from malignant melanoma.

RESULTS

A total of 87 patients with a median age of 62 years (26-85) were treated from 2007-2014. Eighty patients (92%) also had extracranial metastases at time of treatment, and 69 patients (79%) had uncontrolled systemic disease. Seventy-nine patients (91%) underwent single-dose fractions, 7 (8%) underwent 3 fractions, and 1 (1%) was treated in 5 fractions. The mean tumor volume (GTV) treated was 1.92 cc. Five patients developed symptoms of acute phase toxicity, and 4 developed late phase toxicity. None had radionecrosis. The median survival was 6 months. The Kaplan-Meier 1-year survival rate was 31%, and the 1-year local control rate was 91%. The 1-year survival rate for BRAF-positive patients was 42%, and for BRAF-negative patients it was 27%. Forty-two patients (48%) had distant intracranial recurrences, and 1-year distant control rate was 32%.

CONCLUSIONS

SRS is a safe and effective treatment option for intracranial metastases from malignant melanoma. This paper serves as a reference for what is achievable in the absence of highly effective systemic therapy.

Successful treatment of multiple in-transit melanomas on the leg with intensity-modulated radiotherapy and immune checkpoint inhibitors: Report of two cases

Because the efficacy rates of monotherapy with immune checkpoint inhibitors such as nivolumab or ipilimumab are not sufficient, to enhance the antitumor effects of these reagents is of great interest among dermato-oncologists. In this report, we describe two cases of multiple in-transit metastatic melanomas on the leg successfully treated with intensity-modulated radiotherapy (IMRT) using a CyberKnife in combination with ipilimumab or nivolumab. Our cases suggested that IMRT could enhance the antitumor effects of immune checkpoint inhibitors in patients with multiple in-transit melanomas.