The impact of current treatment modalities on the outcomes of patients with melanoma brain metastases: A systematic review

Estimating survival in patients with melanoma brain metastases: prognostic value of lactate dehydrogenase

Patients with melanoma brain metastases (MBM) have poor prognosis, albeit advances in locoregional and systemic treatments. The melanoma-specific Graded Prognostic Assessment (GPA) effectively stratifies survival for patients with MBM. Nevertheless, lactate dehydrogenase (LDH), a well known prognostic factor for patients with melanoma, is not represented in the GPA scores and might add prognostic information for patients with MBM. In this study, 150 consecutive patients with MBM were retrospectively analyzed with the aim of evaluating independent prognostic factors for MBM patients, including LDH. Furthermore, we implemented a disease-specific prognostic score and estimated survival according to treatment modalities. On the basis of multivariable Cox regression analyses, six prognostic factors (age, BRAF status, number of MBM, number of extracranial metastatic sites, performance status, and LDH level) resulted statistically significant in terms of survival and were combined in a prognostic score to stratify patients in distinct prognostic groups ( P  < 0.0001). Among treatment modalities, a multimodal approach with stereotactic radiosurgery or neurosurgery associated with systemic therapy showed the best outcome (median overall survival: 12.32 months, 95% confidence interval, 7.92-25.30). This is the first study to demonstrate that LDH has independent prognostic value for patients with MBM and might be used to improve prognostic stratification, albeit external validation is mandatory. Survival of patients with MBM is affected by both disease-specific risk factors and treatment modalities, with locoregional treatments associated with better outcomes.

Radiation therapy for melanoma brain metastases: a systematic review

BACKGROUND

Radiation therapy (RT) for melanoma brain metastases, delivered either as whole brain radiation therapy (WBRT) or as stereotactic radiosurgery (SRS), is an established component of treatment for this condition. However, evidence allowing comparison of the outcomes, advantages and disadvantages of the two RT modalities is scant, with very few randomised controlled trials having been conducted. This has led to considerable uncertainty and inconsistent guideline recommendations. The present systematic review identified 112 studies reporting outcomes for patients with melanoma brain metastases treated with RT. Three were randomised controlled trials but only one was of sufficient size to be considered informative. Most of the evidence was from non-randomised studies, either specific treatment series or disease cohorts. Criteria for determining treatment choice were reported in only 32 studies and the quality of these studies was variable. From the time of diagnosis of brain metastasis, the median survival after WBRT alone was 3.5 months (IQR 2.4-4.0 months) and for SRS alone it was 7.5 months (IQR 6.7-9.0 months). Overall patient survival increased over time (pre-1989 to 2015) but this was not apparent within specific treatment groups.

CONCLUSIONS

These survival estimates provide a baseline for determining the incremental benefits of recently introduced systemic treatments using targeted therapy or immunotherapy for melanoma brain metastases.

Current Treatment Approaches and Global Consensus Guidelines for Brain Metastases in Melanoma

Background

Up to 60% of melanoma patients develop melanoma brain metastases (MBM), which traditionally have a poor diagnosis. Current treatment strategies include immunotherapies (IO), targeted therapies (TT), and stereotactic radiosurgery (SRS), but there is considerable heterogeneity across worldwide consensus guidelines.

Objective

To summarize current treatments and compare worldwide guidelines for the treatment of MBM.

Methods

Review of global consensus treatment guidelines for MBM patients.

Results

Substantial evidence supported that concurrent IO or TT plus SRS improves progression-free survival (PFS) and overall survival (OS). Guidelines are inconsistent with regards to recommendations for surgical resection of MBM, since surgical resection of symptomatic lesions alleviates neurological symptoms but does not improve OS. Whole-brain radiation therapy is not recommended by all guidelines due to negative effects on neurocognition but can be offered in rare palliative scenarios.

Conclusion

Worldwide consensus guidelines consistently recommend up-front combination IO or TT with or without SRS for the treatment of MBM.

Factors Determining Long-Term Antitumor Responses to Immune Checkpoint Blockade Therapy in Melanoma

With the increasing promise of long-term survival with immune checkpoint blockade (ICB) therapies, particularly for patients with advanced melanoma, clinicians and investigators are driven to identify prognostic and predictive factors that may help to identify individuals who are likely to experience durable benefit. Several ICB combinations are being actively developed to expand the armamentarium of treatments for patients who may not achieve long-term responses to ICB single therapies alone. Thus, negative predictive markers are also of great interest. This review seeks to deepen our understanding of the mechanisms underlying the durability of ICB treatments. We will discuss the currently available long-term data from the ICB clinical trials and real-world studies describing the survivorship of ICB-treated melanoma patients. Additionally, we explore the current treatment outcomes in patients rechallenged with ICB and the patterns of ICB resistance based on sites of disease, namely, liver or CNS metastases. Lastly, we discuss the landscape in melanoma in the context of prognostic or predictive factors as markers of long-term response to ICB.

Anti-tumor treatment and healthcare consumption near death in the era of novel treatment options for patients with melanoma brain metastases

Background

Effective systemic treatments have revolutionized the management of patients with metastatic melanoma, including those with brain metastases. The extent to which these treatments influence disease trajectories close to death is unknown. Therefore, this study aimed to gain insight into provided treatments and healthcare consumption during the last 3 months of life in patients with melanoma brain metastases.

Methods

Retrospective, single-center study, including consecutive patients with melanoma brain metastases diagnosed between June-2015 and June-2018, referred to the medical oncologist, and died before November-2019. Patient and tumor characteristics, anti-tumor treatments, healthcare consumption, presence of neurological symptoms, and do-not-resuscitate status were extracted from medical charts.

Results

100 patients were included. A BRAF-mutation was present in 66 patients. Systemic anti-tumor therapy was given to 72% of patients during the last 3 months of life, 34% in the last month, and 6% in the last week. Patients with a BRAF-mutation more frequently received systemic treatment during the last 3 (85% vs. 47%) and last month (42% vs. 18%) of life than patients without a BRAF-mutation. Furthermore, patients receiving systemic treatment were more likely to visit the emergency room (ER, 75% vs. 36%) and be hospitalized (75% vs. 36%) than those who did not.

Conclusion

The majority of patients with melanoma brain metastases received anti-tumor treatment during the last 3 months of life. ER visits and hospitalizations occurred more often in patients on anti-tumor treatment. Further research is warranted to examine the impact of anti-tumor treatments close to death on symptom burden and care satisfaction.

Oncologic Outcome and Immune Responses of Radiotherapy with Anti-PD-1 Treatment for Brain Metastases Regarding Timing and Benefiting Subgroups

While immune checkpoint inhibitors (ICIs) in combination with radiotherapy (RT) are widely used for patients with brain metastasis (BM), markers that predict treatment response for combined RT and ICI (RT-ICI) and their optimal dosing and sequence for the best immunogenic effects are still under investigation. The aim of this study was to evaluate prognostic factors for therapeutic outcome and to compare effects of concurrent and non-concurrent RT-ICI. We retrospectively analyzed data of 93 patients with 319 BMs of different cancer types who received PD-1 inhibitors and RT at the University Hospital Cologne between September/2014 and November/2020. Primary study endpoints were overall survival (OS), progression-free survival (PFS), and local control (LC). We included 66.7% melanoma, 22.8% lung, and 5.5% other cancer types with a mean follow-up time of 23.8 months. Median OS time was 12.19 months. LC at 6 months was 95.3% (concurrent) vs. 69.2% (non-concurrent; p = 0.008). Univariate Cox regression analysis detected following prognostic factors for OS: neutrophil-to-lymphocyte ratio NLR favoring <3 (low; HR 2.037 (1.184−3.506), p = 0.010), lactate dehydrogenase (LDH) favoring ≤ULN (HR 1.853 (1.059−3.241), p = 0.031), absence of neurological symptoms (HR 2.114 (1.285−3.478), p = 0.003), RT concept favoring SRS (HR 1.985 (1.112−3.543), p = 0.019), RT dose favoring ≥60 Gy (HR 0.519 (0.309−0.871), p = 0.013), and prior anti-CTLA4 treatment (HR 0.498 (0.271−0.914), p = 0.024). Independent prognostic factors for OS were concurrent RT-ICI application (HR 0.539 (0.299−0.971), p = 0.024) with a median OS of 17.61 vs. 6.83 months (non-concurrent), ECOG performance status favoring 0 (HR 7.756 (1.253−6.061), p = 0.012), cancer type favoring melanoma (HR 0.516 (0.288−0.926), p = 0.026), BM volume (PTV) favoring ≤3 cm3 (HR 1.947 (1.007−3.763), p = 0.048). Subgroups with the following factors showed significantly longer OS when being treated concurrently: RT dose <60 Gy (p = 0.014), PTV > 3 cm3 (p = 0.007), other cancer types than melanoma (p = 0.006), anti-CTLA4-naïve patients (p < 0.001), low NLR (p = 0.039), steroid intake ≤4 mg (p = 0.042). Specific immune responses, such as abscopal effects (AbEs), pseudoprogression (PsP), or immune-related adverse events (IrAEs), occurred more frequently with concurrent RT-ICI and resulted in better OS. Other toxicities, including radionecrosis, were not statistically different in both groups. The concurrent application of RT and ICI, the ECOG-PS, cancer type, and PTV had an independently prognostic impact on OS. In concurrently treated patients, treatment response (LC) was delayed and specific immune responses (AbE, PsP, IrAE) occurred more frequently with longer OS rates. Our results suggest that concurrent RT-ICI application is more beneficial than sequential treatment in patients with low pretreatment inflammatory status, more and larger BMs, and with other cancer types than melanoma.

Radiomics for the noninvasive prediction of the BRAF mutation status in patients with melanoma brain metastases

BACKGROUND

The BRAF V600E mutation is present in approximately 50% of patients with melanoma brain metastases and an important prerequisite for response to targeted therapies, particularly BRAF inhibitors. As heterogeneity in terms of BRAF mutation status may occur in melanoma patients, a wild-type extracranial primary tumor does not necessarily rule out a targetable mutation in brain metastases using BRAF inhibitors. We evaluated the potential of MRI radiomics for a noninvasive prediction of the intracranial BRAF mutation status.

METHODS

Fifty-nine patients with melanoma brain metastases from two university brain tumor centers (group 1, 45 patients; group 2, 14 patients) underwent tumor resection with subsequent genetic analysis of the intracranial BRAF mutation status. Preoperative contrast-enhanced MRI was manually segmented and analyzed. Group 1 was used for model training and validation, group 2 for model testing. After radiomics feature extraction, a test-retest analysis was performed to identify robust features prior to feature selection. Finally, the best performing radiomics model was applied to the test data. Diagnostic performances were evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

Twenty-two of 45 patients (49%) in group 1, and 8 of 14 patients (57%) in group 2 had an intracranial BRAF V600E mutation. A linear support vector machine classifier using a six-parameter radiomics signature yielded an area under the ROC curve of 0.92 (sensitivity, 83%; specificity, 88%) in the test data.

CONCLUSIONS

The developed radiomics classifier allows a noninvasive prediction of the intracranial BRAF V600E mutation status in patients with melanoma brain metastases with high diagnostic performance.

Treatment for Brain Metastases: ASCO-SNO-ASTRO Guideline

PURPOSE

To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors.

METHODS

ASCO convened an Expert Panel and conducted a systematic review of the literature.

RESULTS

Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base.

RECOMMENDATIONS

Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non-small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy.Additional information is available at www.asco.org/neurooncology-guidelines.

Focal Radiotherapy of Brain Metastases in Combination With Immunotherapy and Targeted Drug Therapy

BACKGROUND

Advances in systemic treatment and in brain imaging have led to a higher incidence of diagnosed brain metastases. In the treatment of brain metastases, stereotactic radiotherapy and radiosurgery, systemic immunotherapy, and targeted drug therapy are important evidence-based options. In this review, we summarize the available evidence on the treatment of brain metastases of the three main types of cancer that give rise to them: non-small-cell lung cancer, breast cancer, and malignant melanoma.

METHODS

This narrative review is based on pertinent original articles, meta-analyses, and systematic reviews that were retrieved by a selective search in PubMed. These publications were evaluated and discussed by an expert panel including radiation oncologists, neurosurgeons, and oncologists.

RESULTS

There have not yet been any prospective randomized trials concerning the optimal combination of local stereotactic radiotherapy/radiosurgery and systemic immunotherapy or targeted therapy. Retrospective studies have consistently shown a benefit from early combined treatment with systemic therapy and (in particular) focal radiotherapy, compared to sequential treatment. Two metaanalyses of retrospective data from cohorts consisting mainly of patients with non-small-cell lung cancer and melanoma revealed longer overall survival after combined treatment with focal radiotherapy and checkpoint inhibitor therapy (rate of 12-month overall survival for combined versus non-combined treatment: 64.6% vs. 51.6%, p <0.001). In selected patients with small, asymptomatic brain metastases in non-critical locations, systemic therapy without focal radiotherapy can be considered, as long as follow-up with cranial magnetic resonance imaging can be performed at close intervals.

CONCLUSION

Brain metastases should be treated by a multidisciplinary team, so that the optimal sequence of local and systemic therapies can be determined for each individual patient.

Value of screening and follow-up brain MRI scans in patients with metastatic melanoma

Background

Novel treatments make long‐term survival possible for subsets of patients with melanoma brain metastases. Brain magnetic resonance imaging (MRI) may aid in early detection of brain metastases and inform treatment decisions. This study aimed to determine the impact of screening MRI scans in patients with metastatic melanoma and follow‐up MRI scans in patients with melanoma brain metastases.

Methods

This retrospective cohort study included patients diagnosed with metastatic melanoma or melanoma brain metastases between June 2015 and January 2018. The impact of screening MRI scans was evaluated in the first 2 years after metastatic melanoma diagnosis. The impact of follow‐up MRI scans was examined in the first year after brain metastases diagnosis. The number of MRI scans, scan indications, scan outcomes, and changes in treatment strategy were analyzed.

Results

In total, 116 patients had no brain metastases at the time of the metastatic melanoma diagnosis. Twenty‐eight of these patients (24%) were subsequently diagnosed with brain metastases. Screening MRI scans detected the brain metastases in 11/28 patients (39%), of which 8 were asymptomatic at diagnosis. In the 96 patients with melanoma brain metastases, treatment strategy changed after 75/168 follow‐up MRI scans (45%). In patients treated with immune checkpoint inhibitors, the number of treatment changes after follow‐up MRI scans was lower when patients had been treated longer.

Conclusion(s)

Screening MRI scans aid in early detection of melanoma brain metastases, and follow‐up MRI scans inform treatment strategy. In patients with brain metastases responding to immune checkpoint inhibitors, treatment changes were less frequently observed after follow‐up MRI scans. These results can inform the development of brain imaging protocols for patients with immune checkpoint inhibitor sensitive tumors.

Systemic therapy augmented by radiotherapy (STAR) effect for brain metastases in a BRAF-mutated melanoma patient with prolonged survival: a case report

Brain metastases are common in stage IV malignant melanoma, carrying a prognosis traditionally regarded as severe, with a median survival of few months. Recently introduced systemic therapies as targeted therapy or immunotherapy have significantly improved the prognosis of metastatic melanoma. The optimal association of radiotherapy to such novel treatments has to be clarified. We report on a 43-year-old woman with 10 brain metastases. Three of them were treated with stereotactic radiosurgery (SRS) with complete response even of the untreated lesions. As the patient was BRAF-mutated, she was started on dabrafenib/trametinib. After 8 months she developed new brain metastases, which again responded to a new treatment with SRS. As after 7 months additional lesions appeared, she was treated with whole brain radiotherapy and was started on nivolumab. Twenty months after the first diagnosis of brain metastases the patient is fit without significant clinical and radiological signs of toxicity.

Systemic Therapy of Metastatic Melanoma: On the Road to Cure

Simple Summary

Malignant melanoma is more dangerous than most other skin cancers due to its ability to spread early and aggressively. Until the development of new therapeutic strategies, the median survival of patients with metastatic melanoma was just a few months. Immunotherapy, the first regimen, leading to significant improvement, blocks immune checkpoints, which normally dampen immune responses, enabling our defense cells to recognize and destroy cancer cells again. Immunotherapy achieves long-term survival in about 50% of metastatic melanoma patients. Besides, targeted therapy has also significantly improved the survival of melanoma patients, blocking cell-signaling proteins, which are altered in about 50% of melanomas and lead to uncontrolled tumor cell growth. In addition to the approved regimens, there are numerous new treatment strategies, ranging from modified viruses to personalized immune cells that attack and destroy tumor cells. This review shall give an insight into both already approved regimens and upcoming developments.

Abstract

This decade has brought significant survival improvement in patients with metastatic melanoma with targeted therapies and immunotherapies. As our understanding of the mechanisms of action of these therapeutics evolves, even more impressive therapeutic success is being achieved through various combination strategies, including combinations of different immunotherapies as well as with other modalities. This review summarizes prospectively and retrospectively generated clinical evidence on modern melanoma therapy, focusing on immunotherapy and targeted therapy with BRAF kinase inhibitors and MEK kinase inhibitors (BRAF/MEK inhibitors), including recent data presented at major conference meetings. The combination of the anti-PD-1 directed monoclonal antibody nivolumab and of the CTLA-4 antagonist ipilimumab achieves unprecedented 5-year overall survival (OS) rates above 50%; however, toxicity is high. For PD-1 monotherapy (nivolumab or pembrolizumab), toxicities are in general well manageable. Today, novel combinations of such immune checkpoint inhibitors (ICIs) are under investigation, for example with cytokines and oncolytic viruses (i.e., pegylated interleukin-2, talimogene laherparepvec). Furthermore, current studies investigate the combined or sequential use of ICIs plus BRAF/MEK inhibitors. Several studies focus particularly on poor prognosis patients, as e.g., on anti-PD-1 refractory melanoma, patients with brain metastases, or uveal melanoma. It is hoped, on the road to cure, that these new approaches further improve long term survival in patients with advanced or metastatic melanoma.

Local failure after stereotactic radiosurgery (SRS) for intracranial metastasis: analysis from a cooperative, prospective national registry

INTRODUCTION

Stereotactic radiosurgery (SRS) has been increasingly employed to treat patients with intracranial metastasis, both as a salvage treatment after failed whole brain radiation therapy (WBRT) and as an initial treatment. "Several studies have shown that SRS may be as effective as WBRT with the added benefit of preserving neuro-cognition". However, some patients may have local failure following SRS for intracranial metastasis, defined as increase in total lesion volume by 25% after at least 3 months of follow up.

METHODS

The SRS registry, established by the Neuro point alliance (NPA) under the auspices of the American Association of Neurological Surgeons (AANS), was queried for patients with intracranial metastasis receiving SRS at the participating sites. Demographic, clinical symptoms, tumor, and treatment characteristics as well as follow up status were summarized for the cohort. A multivariable explanatory cox- regression was performed to evaluate the impact of each of the factors on time to local failure.at last follow-up.

RESULTS

A total of 441 patients with 1255 intracranial metastatic lesions undergoing SRS were identified. The most common primary cancer histology was non-small cell lung cancer (43.8%, n = 193). More than half of the cohort had more than 1 metastatic lesion (2-3 lesions: 29.5%, n = 130; more than 3 lesions: 25.2% (n = 111). The average duration of follow-up for the cohort was found to be 8.4 months (SD = 7.61). The mean clinical treatment volume (CTV), after adding together the volume of each lesion for each patient was 5.39 cc (SD = 7.6) at baseline. A total of 20.2% (n = 89) had local failure (increase in volume by  > 25%) with a mean time to progression of 7.719 months (SD = 6.09). The progression free survival (PFS) for the cohort at 3, 6 and 12 months were found to be 94.9%, 84.3%, and 69.4%, respectively. On multivariable cox regression analysis, factors associated with increased hazard of local failure included male gender (HR 1.65, 95% CI 1.03-2.66, p = 0.037), chemotherapy at or before SRS (HR = 2.39, 95% CI 1.41-4.05, p = 0.001), WBRT at or before SRS (HR = 2.21, 95% CI 1.16- 4.22, p = 0.017), while surgical resection (HR 0.45, 95% CI 0.21-0. 97, p = 0.04) and immunotherapy (0.34, 95% CI 0.16-0.50, p = 0.014) were associated with lower hazard of local failure.

CONCLUSION

Factors found to be predictive of local failure included higher RPA score and those receiving chemotherapy, while patients undergoing surgical resection and those with occipital lobe lesions were less likely to experience local failure. Our analyses not only corroborate those previously reported but also demonstrate the utility of a multi-institutional registry to advance real-world SRS research for patients with intracranial metastatic lesions.

Radiotherapy in combination with systemic therapies for brain metastases: current status and progress

Brain metastases (BMs) are the most common cause of intracranial neoplasms in adults with poor prognosis. Most BMs originate from lung cancer, breast cancer, or melanoma. Radiotherapy (RT), including whole brain radiotherapy (WBRT) and stereotactic radiation surgery (SRS), has been widely explored and is considered a mainstay anticancer treatment for BMs. Over the past decade, the advent of novel systemic therapies has revolutionized the treatment of BMs. In this context, there is a strong rationale for using a combination of treatments based on RT, with the aim of achieving both local disease control and extracranial disease control. This review focuses on describing the latest progress in RT as well as the synergistic effects of the optimal combinations of RT and systemic treatment modalities for BMs, to provide perspectives on current treatments.

Brain Metastases Unresponsive to Immunotherapy Detected by 18F-FDG-PET/CT in a Patient with Melanoma

Recently, newer therapies such as immunotherapy have been increasingly used in the treatment of several tumors, including advanced melanoma. In particular, several studies showed that the combination of ipilimumab, an anti-Cytotoxic T-lymphocyte Associated Protein 4 (CTLA-4) monoclonal antibody and nivolumab, an anti-Programmed Death 1 (PD-1) monoclonal antibody, leads to improved survival in patients with metastatic melanoma. Despite that, immunotherapeutic agents may not reach therapeutic concentration in the brain due to the blood–brain barrier. We report the case of a 50-year-old man with advanced melanoma who underwent whole-body 18F-FDG-PET/CT before and after treatment with immunotherapy showing resistant brain metastases confirmed by subsequent MRI of the brain. Moreover, 18F-FDG-PET/CT was able to detect an immune-related adverse event such as enterocolitis that contributed to the worsening of patient conditions. This case shows how a whole-body methodology such as 18F-FDG-PET/CT can be useful in identifying melanoma cancer patients unresponsive to immunotherapy that may benefit from traditional palliative therapy in the effort to improve their quality of life.