Cranial irradiation after surgical excision of brain metastases in melanoma patients

Prevention of Brain Metastases: A New Frontier

This review discusses the topic of prevention of brain metastases from the most frequent solid tumor types, i.e., lung cancer, breast cancer and melanoma. Within each tumor type, the risk of brain metastasis is related to disease status and molecular subtype (i.e., EGFR-mutant non-small cell lung cancer, HER2-positive and triple-negative breast cancer, BRAF and NRAF-mutant melanoma). Prophylactic cranial irradiation is the standard of care in patients in small cell lung cancer responsive to chemotherapy but at the price of late neurocognitive decline. More recently, several molecular agents with the capability to target molecular alterations driving tumor growth have proven as effective in the prevention of secondary relapse into the brain in clinical trials. This is the case for EGFR-mutant or ALK-rearranged non-small cell lung cancer inhibitors, tucatinib and trastuzumab-deruxtecan for HER2-positive breast cancer and BRAF inhibitors for melanoma. The need for screening with an MRI in asymptomatic patients at risk of brain metastases is emphasized.

Changes In Outcomes And Factors Associated With Survival In Melanoma Patients With Brain Metastases

BACKGROUD

Treatment options for patients with melanoma brain metastasis (MBM) have changed significantly in the last decade. Few studies have evaluated changes in outcomes and factors associated with survival in MBM patients over time. The aim of this study is to evaluate changes in clinical features and overall survival (OS) for MBM patients.

METHODS

Patients diagnosed with MBMs from 1/1/2009-12/31/2013 (Prior Era; PE) and 1/1/2014-12/31/2018 (Current Era; CE) at The University of Texas MD Anderson Cancer Center were included in this retrospective analysis. The primary outcome measure was OS. Log-rank test assessed differences between groups; multivariable analyses were performed with Cox proportional hazards models and recursive partitioning analysis (RPA).

RESULTS

791 MBM patients (PE, n=332; CE, n=459) were included in analysis. Median OS from MBM diagnosis was 10.3 months (95% CI, 8.9 - 12.4) and improved in the CE versus PE (14.4 vs. 10.3 months, P < .001). Elevated serum LDH was the only factor associated with worse OS in both PE and CE patients. Factors associated with survival in CE MBM patients included patient age, primary tumor Breslow thickness, prior immunotherapy, leptomeningeal disease (LMD), symptomatic MBMs, and whole brain radiation therapy (WBRT). Several factors associated with OS in the PE were not significant in the CE. RPA demonstrated that elevated serum LDH and prior immunotherapy treatment are the most important determinants of survival in CE MBM patients.

CONCLUSIONS

OS and factors associated with OS have changed for MBM patients. This information can inform contemporary patient management and clinical investigations.

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.

Significant survival improvements for patients with melanoma brain metastases: can we reach cure in the current era?

PURPOSE

New therapies for melanoma have been associated with increasing survival expectations, as opposed to the dismal outcomes of only a decade ago. Using a prospective registry, we aimed to define current survival goals for melanoma patients with brain metastases (BM), based on state-of-the-art multimodality care.

METHODS

We reviewed 171 melanoma patients with BM receiving stereotactic radiosurgery (SRS) who were followed with point-of-care data collection between 2012 and 2020. Clinical, molecular and imaging data were collected, including systemic treatment and radiosurgical parameters.

RESULTS

Mean age was 63 ± 15 years, 39% were female and 29% had BRAF-mutated tumors. Median overall survival after radiosurgery was 15.7 months (95% Confidence Interval 11.4-27.7) and 25 months in patients managed since 2015. Thirty-two patients survived [Formula: see text] 5 years from their initial SRS. BRAF mutation-targeted therapies showed a survival advantage in comparison to chemotherapy (p = 0.009), but not to immunotherapy (p = 0.09). In a multivariable analysis, both immunotherapy and the number of metastases at 1^st SRS were predictors of long-term survival ([Formula: see text] 5 years) from initial SRS (p = 0.023 and p = 0.018, respectively). Five patients (16%) of the long-term survivors required no active treatment for [Formula: see text] 5 years.

CONCLUSION

Long-term survival in patients with melanoma BM is achievable in the current era of SRS combined with immunotherapies. For those alive [Formula: see text] 5 years after first SRS, 16% had been also off systemic or local brain therapy for over 5 years. Given late recurrences of melanoma, caution is warranted, however prolonged survival off active treatment in a subset of our patients raises the potential for cure.

Immunotherapy and radiotherapy in melanoma: a multidisciplinary comprehensive review

Melanoma is an extremely aggressive tumor and is considered to be an extremely immunogenic tumor because compared to other cancers it usually presents a well-expressed lymphoid infiltration. The aim of this paper is to perform a multidisciplinary comprehensive review of the evidence available about the combination of radiotherapy and immunotherapy for melanoma. Radiation, in fact, can increase tumor antigens visibility and promote priming of T cells but can also exert immunosuppressive action on tumor microenvironment. Combining radiotherapy with immunotherapy provides an opportunity to increase immunostimulatory potential of radiation. We therefore provide the latest clinical evidence about radiobiological rationale, radiotherapy techniques, timing, and role both in advanced and systemic disease (with a special focus on ocular melanoma and brain, liver, and bone metastases) with a particular attention also in geriatric patients. The combination of immunotherapy and radiotherapy seems to be a safe therapeutic option, supported by a clear biological rationale, even though the available data confirm that radiotherapy is employed more for metastatic than for non-metastatic disease. Such a combination shows promising results in terms of survival outcomes; however, further studies, hopefully prospective, are needed to confirm such evidence.

Is there any survival benefit from post-operative radiation in brain metastases? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The benefits of adding upfront post-operative radiation, either whole-brain (WBRT) or cavity, after resection of brain metastases have been debated, particularly due to the long-term sequalae post radiation. We sought to compare the efficacy and safety between post-operative radiation versus resection alone.

METHODS

We searched various biomedical databases from 1983 to 2018, for eligible randomized controlled trials (RCT). Outcomes studied were local recurrence (LR), overall survival (OS) and serious (Grade 3 + ) adverse events. We used the random effects model to pool outcomes. Methodological quality of each study was assessed using the Cochrane Risk of Bias tool. We employed the GRADE approach to assess the certainty of evidence.

RESULTS

We included 5 RCTs comprising of 673 patients. The pooled odds ratio (OR) for LR is 0.26 (95% confidence interval (CI) 0.19-0.37, P < 0.001, GRADE certainty high), strongly supporting the use of post-operative radiation. Meta-regression analysis done comparing cavity and WBRT, did not show any difference in LR. The pooled hazard ratio (HR) for overall survival (OS) is 1.1 (95% CI 0.90-1.34, P = 0.37, GRADE certainty high). The treatment-related toxicities could not be pooled; the 2 studies which reported this did not find differences between the approaches. The risk of bias across the included studies was low.

CONCLUSION

Our analysis confirms that upfront post-operative radiation significantly reduces the risk of LR. However, the lack of improvement in OS suggests that local control alone may not impact survival. Balancing local control, and neuro-cognitive effects of WBRT, cavity radiation seems to be a safe and effective option.

Current Treatment of Melanoma Brain Metastasis

OPINION STATEMENT

With greater understanding of underlying biology and development of effective BRAF-targeted therapy and immunotherapy, along with remarkable advances in local treatment such as stereotactic radiosurgery, melanoma brain metastasis (MBM) is witnessing continually improving outcome, with 1-year overall survival rate approaching 85%. Given disease complexity and myriad treatment options, all patients with MBM should ideally be evaluated in a multidisciplinary setting to allow an individualized treatment approach based on prognostic groups, molecular classification, number and size of brain metastasis, and performance status. With improving outcome, pendulum has now swayed to focus more on effective treatment modalities with minimal neurological toxicity while maintaining quality of life. Surgery is usually considered in symptomatic and large MBMs, while stereotactic radiosurgery considered in 1-4 lesions, and now also being explored for up to 15 brain metastases for improved local control. The role of whole brain radiotherapy is diminishing given its neurocognitive toxicities and is reserved for patients with diffuse brain involvement. Cytotoxic chemotherapy has largely been ineffective without evidence for survival benefit. Immune checkpoint inhibitors have become the cornerstone of management for melanoma brain metastasis with durable intracranial tumor control and excellent toxicity profile. For patients with asymptomatic MBMs, ipilimumab and nivolumab have shown intracranial response near 60% and provides comparable clinical benefit in MBMs as for extracranial metastases. For patients with driver BRAF mutation, BRAFi-/MEKi-targeted agents are proven to be effective in MBM with high rate intracranial responses (44-59%). However, the durability of intracranial responses induced by BRAFi/MEKi seems to be shorter than that of extracranial disease. Emerging data support novel combination of systemic therapy and stereotactic radiosurgery, which appears to be safe and effective; however, potential benefits and risks should be evaluated prospectively. Promising ongoing trials will further expand therapeutic evidence in MBM, and patients should be encouraged to participate in clinical trials.

Purely Meningeal Intracranial Relapse of Melanoma Brain Metastases After Surgical Resection and Immunotherapy as a Unique Disease Progression Pattern: Our Experience and Review of the Literature

BACKGROUND

We present a case of 72-year-old man with a history of metastatic melanoma diagnosed in 2015 presenting a stable disease in treatment with dabrafenib.

CASE DESCRIPTION

The patient had been surgically treated for a presumed intracranial parietooccipital metastasis. He presented 1 month later with a meningeal lesion associated with a subdural hematoma. A second surgical treatment confirmed the diagnosis of meningeal recurrence of metastatic melanoma.

CONCLUSIONS

The most recent literature lacks studies defining the clinical phenomena of an early recurrence of intracranial melanoma with de novo involvement of dural compartment in patients in treatment with a target immunotherapy. The aim of this present study is to report a case of early recurrence of intracranial melanoma metastases with evidence of fast immunohistochemical and macroscopical mutation of pathologic elements, with an analysis of literature that shows the lack of well-described occurrences.

The combination of stereotactic radiosurgery with immune checkpoint inhibition or targeted therapy in melanoma patients with brain metastases: a retrospective study

BACKGROUND

Evidence pointing to a synergistic effect of stereotactic radiosurgery (SRS) with concurrent immunotherapy or targeted therapy in patients with melanoma brain metastases (BM) is increasing. We aimed to analyze the effect on overall survival (OS) of immune checkpoint inhibitors (ICI) or BRAF/MEK inhibitors initiated during the 9 weeks before or after SRS. We also evaluated the prognostic value of patients' and disease characteristics as predictors of OS in patients treated with SRS.

METHODS

We identified patients with BM from cutaneous or unknown primary origin melanoma treated with SRS between 2011 and 2018.

RESULTS

We included 84 patients. The median OS was 12 months (95% CI 9-20 months). The median follow-up was 30 months (95% CI 28-49). Twenty-eight patients with newly diagnosed BM initiated anti-PD-1 +/-CTLA-4 therapy (n = 18), ipilimumab monotherapy (n = 10) or BRAF+/- MEK inhibitors (n = 11), during the 9 weeks before or after SRS. Patients who received anti-PD-1 +/-CTLA-4 mAb showed an improved survival in comparison to ipilimumab monotherapy (OS 24 vs. 7.5 months; HR 0.32, 95% 0.12-0.83, p = 0.02) and BRAF +/-MEK inhibitors (OS 24 vs. 7 months, respectively; HR 0.11, 95% 0.04-0.34, p = 0.0001). This benefit remained significant when compared to the subgroup of patients treated with dual BRAF/MEK inhibition (BMi) (n = 5). In a multivariate Cox regression analysis an age > 65, synchronous BM, > 2 metastatic sites, > 4 BM, and an ECOG > 1 were correlated with poorer prognosis. A treatment with anti-PD-1+/-CTLA-4 mAbs within 9 weeks of SRS was associated with better outcomes. The presence of serum lactate dehydrogenase (LDH) levels ≥ 2xULN at BM diagnosis was associated with lower OS (HR 1.60, 95% CI 1.03-2.50; p = 0.04).

CONCLUSIONS

The concurrent administration of anti-PD-1+/-CTLA-4 mAbs with SRS was associated with improved survival in melanoma patients with newly diagnosed BM. In addition to CNS tumor burden, the extension of systemic disease retains its prognostic value in patients treated with SRS. Elevated serum LDH levels are predictors of poor outcome in these patients.

Management of brain metastases: history and the present

Brain metastases are significant causes of morbidity or mortality for patients with metastatic cancer. With the application of novel systematic therapy and improvement of overall survival, the prevalence of brain metastases is increasing. The paradigm of treatment for brain metastases evolved rapidly during the last 30 years due to the development of technology and emergence of novel therapy. Brain metastases used to be regarded as the terminal stage of cancer and left life expectancy to only 1 month. The application of whole brain radiotherapy for patients with brain metastases increased the life expectancy to 4–6 months in the 1980s. Following studies established surgical resection followed by the application of whole brain radiotherapy the standard treatment for patients with single metastasis and good systematic performance. With the development of stereotactic radiosurgery, stereotactic radiosurgery plus whole brain radiotherapy provides an alternative modality with superior neurocognitive protection at the cost of overall survival. In addition, stereotactic radiosurgery combined with whole brain radiotherapy may offer a promising modality for patients with numerous multiple brain metastases who are not eligible for surgical resection. With the advancing understanding of molecular pathway and biological behavior of oncogenesis and tumor metastasis, novel targeted therapy including tyrosine-kinase inhibitors and immunotherapy are applied to brain metastases. Clinical trials had revealed the efficacy of targeted therapy. Furthermore, the combination of targeted therapy and radiotherapy or chemotherapy is the highlight of current investigation. Advancement in this area may further change the treatment paradigm and offer better modality for patients who are not suitable for surgical resection or radiosurgery.

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.

A phase I study of TPI 287 in combination with temozolomide for patients with metastatic melanoma

TPI 287 is a synthetic taxane derivative with structural modifications allowing for central nervous system penetration and potential circumvention of multidrug resistance efflux pump mechanisms. The aim of this phase I study was to determine the maximum tolerated dose of the combination of TPI 287 and temozolomide in metastatic melanoma. Patients with stage IV unresectable or recurrent stage III melanoma were eligible. Stable untreated or treated brain metastases were allowed. Patients with previous taxane exposure were excluded. TPI 287 was administered intravenously on days 1, 8, and 15 and temozolomide was taken orally daily on days 1-5 of a 28-day cycle. Responses were assessed every two cycles according to WHO criteria. A total of 21 patients were enrolled. The maximum tolerated dose of the combination at this schedule was determined to be 125 mg/m intravenous of TPI 287 and 110 mg/m of oral temozolomide. The dose-limiting toxicity was neuropathy and six patients experienced grade III neuropathy. All patients were evaluable for tumor response. There were no complete responses; there were two partial responses and seven patients had stable disease (overall response rate 9.5% and disease control rate 42.9%). Three patients had stable disease in the brain despite progressive extracranial disease. The combination of TPI 287 and temozolomide is well tolerated in patients with metastatic melanoma, with the exception of neuropathy. The central nervous system penetration of both agents makes this a rational combination for further testing in primary and metastatic brain lesions.

Melanoma central nervous system metastases: current approaches, challenges, and opportunities

Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area.

Melanoma Brain Metastasis: Mechanisms, Models, and Medicine

The development of brain metastases in patients with advanced stage melanoma is common, but the molecular mechanisms responsible for their development are poorly understood. Melanoma brain metastases cause significant morbidity and mortality and confer a poor prognosis; traditional therapies including whole brain radiation, stereotactic radiotherapy, or chemotherapy yield only modest increases in overall survival (OS) for these patients. While recently approved therapies have significantly improved OS in melanoma patients, only a small number of studies have investigated their efficacy in patients with brain metastases. Preliminary data suggest that some responses have been observed in intracranial lesions, which has sparked new clinical trials designed to evaluate the efficacy in melanoma patients with brain metastases. Simultaneously, recent advances in our understanding of the mechanisms of melanoma cell dissemination to the brain have revealed novel and potentially therapeutic targets. In this review, we provide an overview of newly discovered mechanisms of melanoma spread to the brain, discuss preclinical models that are being used to further our understanding of this deadly disease and provide an update of the current clinical trials for melanoma patients with brain metastases.

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

Brain metastases are a common occurrence in patients with melanoma. Prognosis is poor. Radiotherapy is the main local treatment for brain metastases. Recently, immunotherapy (i.e. immune checkpoints inhibitors) showed a significant impact on the prognosis of patients with metastatic melanoma, also in the setting of patients with brain metastases. Despite various possible treatments, survival of patients with melanoma brain metastases is still unsatisfactory; new treatment modalities or combination of therapies need to be explored. Being immunotherapy and radiotherapy alone both efficient in the treatment of melanoma brain metastases, the combination of these two therapies seems logical. Moreover radiotherapy can improve the efficacy of immunotherapy and the immune system plays a relevant role in the action of radiotherapy. Preclinical data support this combination. Clinical data are more contradictory. In this review, we will discuss available therapies for melanoma brain metastases, focusing on the preclinical and clinical available data supporting the possible synergism between radiotherapy and immunotherapy.

The Efficacy of Postoperative Chemotherapy for Patients with Metastatic Brain Tumors from Non-Small Cell Lung Cancer

BACKGROUND

The purpose of this study is to evaluate the effect of postoperative chemotherapy on recurrence and survival in patients after resection of metastatic brain tumors from non-small cell lung cancers.

METHODS

Patients who went through resection of a single metastatic brain tumor from non-small cell lung cancer from July 2001 to December 2012 were reviewed. Those selected were 77 patients who survived more than 3 months after surgery were selected. Among them, 44 patients received various postoperative systemic chemotherapies, 33 patients received postoperative adjuvant whole brain radiotherapy (WBRT). Local/distant recurrence rate, local/distant recurrence free survival, disease free survival (DFS), and overall survival were compared between the two groups.

RESULTS

Among the 77 patients, there were 19 (24.7%) local recurrences. Local recurrence occurred in 7 (21.2%) of 33 patients in the adjuvant radiotherapy (RT) group and in 12 (27.3%) of the 44 patients in the chemotherapy group (p=0.542). Among the 77 patients, there were 34 (44.1%) distant recurrences. Distant recurrence occurred in 7 (21.2%) of the 33 patients in the adjuvant RT group and in 27 (61.4%) of the 44 patients in the chemotherapy group (p<0.0005). Patients' survival in terms of local recurrence free survival, distant recurrence free survival, DFS, and overall survival was not shown to be statistically different between the two groups before and after adjusting for covariates.

CONCLUSION

There was no significant difference observed between postoperative adjuvant chemotherapy and adjuvant WBRT in terms of patients' survival. Postoperative chemotherapy is more feasible and may be an appropriate option for simultaneous control of both primary and metastatic lesions.

Primary central nervous system amelanotic melanoma in a Hispanic male: Case report

Background

Primary melanotic neoplasms of the central nervous system (CNS) are uncommon; amelanotic melanomas in this region are extremely rare. Very few cases of amelanotic variation of primary melanoma in the CNS were reported on. General guidelines or recommendations to establish this diagnosis do not exist.

Case Report

A sixty-year-old male Hispanic patient presented with a 7-day history of numbness and dizziness. Initial laboratory work-up and physical examination were inconclusive. Cerebral radiological imaging showed a left frontal lesion. Further work-up after clinical deterioration revealed an increase in the lesion size consistent with hemorrhage and changes in T1WI. Biopsy and immunochemistry demonstrated the presence of amelanotic melanoma in the CNS without evidence of another primary lesion.

Conclusions

Primary amelanotic melanoma of the CNS represents a challenge, clinically and diagnostically. Magnetic resonance imaging can be helpful in early stages. Final diagnosis is established with immunohistochemical testing. Physicians should be aware of the existence of this rare manifestation and difficulties faced while building this diagnosis.

Are melanomas averse to cerebellum? Cerebellar metastases in a surgical series

OBJECTIVES

To study the propensity of different cancers to metastasize to the cerebrum and cerebellum, and to study overall survival (OS) and prognostic factors for patients after surgical resection for cerebellar metastases.

MATERIALS AND METHODS

From a prospectively collected tumor database, all patients that underwent a craniotomy for intracranial metastases between 2003 and 2011 at Oslo University Hospital were included.

RESULTS

One hundred and forty patients underwent resection for cerebellar metastases. Most common primary tumor sites were lung, colon/rectum, and breast in 45%, 19%, and 14%, respectively. None were prostate cancers. Melanoma metastases were significantly underrepresented, and colorectal cancer metastases significantly overrepresented in cerebellum, compared to the overall proportion of cerebellar/supratentorial metastases surgically resected (P < 0.05). Thirty-day post-operative mortality rate was 4.3%. Median OS was 7.7 months (95% CI 6.0-9.5 months) irrespective of post-operative adjuvant therapy. Median OS was 51.8, 8.4, and 3.4 months, respectively, for recursive partitioning analysis class 1(n = 11), 2 (n = 78) and 3 (n = 34). Significant negative prognostic factors were age ≥65 years, Karnofsky performance score (KPS) <70, extracranial metastases and uncontrolled systemic disease.

CONCLUSIONS

Melanoma metastases were significantly underrepresented in cerebellum, whereas colorectal cancer metastases were significantly overrepresented. Surgical mortality and OS after surgical treatment of cerebellar metastases were similar to the results of supratentorial metastases.

Factors influencing the CNS distribution of a novel MEK-1/2 inhibitor: implications for combination therapy for melanoma brain metastases

Brain metastases are a major cause of mortality in patients with advanced melanoma. Adequate brain distribution of targeted agents for melanoma will be critical for treatment success. Recently, improvement in overall survival led to US Food and Drug Administration (FDA) approval of the v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors, vemurafenib and dabrafenib, and the mitogen-activated protein kinase kinase-1 (MEK)-1/2 inhibitor, trametinib. However, brain metastases and emergence of resistance remain a significant problem. MEK-1/2 is downstream of BRAF in the mitogen-activated protein kinase (MAPK) signaling pathway, making it an attractive target to combat resistance. The recently approved combination of dabrafenib and trametinib has shown improvement in progression-free survival; however, adequate brain distribution of both compounds is required to effectively treat brain metastases. In previous studies, we found limited brain distribution of dabrafenib. The purpose of the current study was to investigate factors influencing the brain distribution of trametinib. In vitro studies indicated that trametinib is a substrate for both P-glycoprotein (P-gp) and Bcrp, efflux transporters found at the blood-brain barrier. In vivo studies in transgenic mouse models confirmed that P-gp plays an important role in restricting brain distribution of trametinib. The brain-to-plasma partition coefficient (AUCbrain/AUCplasma) was approximately 5-fold higher in Mdr1a/b((-/-)) (P-gp knockout) and Mdr1a/b((-/-))Bcrp1((-/-)) (triple knockout) mice when compared with wild-type and Bcrp1((-/-)) (Bcrp knockout) mice. The brain distribution of trametinib was similar between the wild-type and Bcrp knockout mice. These results show that P-gp plays an important role in limiting brain distribution of trametinib and may have important implications for use of trametinib as single agent or in combination therapy for treatment of melanoma brain metastases.

Molecular profiling of patient-matched brain and extracranial melanoma metastases implicates the PI3K pathway as a therapeutic target

PURPOSE

An improved understanding of the molecular pathogenesis of brain metastases, one of the most common and devastating complications of advanced melanoma, may identify and prioritize rational therapeutic approaches for this disease. In particular, the identification of molecular differences between brain and extracranial metastases would support the need for the development of organ-specific therapeutic approaches.

EXPERIMENTAL DESIGN

Hotspot mutations, copy number variations (CNV), global mRNA expression patterns, and quantitative analysis of protein expression and activation by reverse-phase protein array (RPPA) analysis were evaluated in pairs of melanoma brain metastases and extracranial metastases from patients who had undergone surgical resection for both types of tumors.

RESULTS

The status of 154 previously reported hotspot mutations, including driver mutations in BRAF and NRAS, were concordant in all evaluable patient-matched pairs of tumors. Overall patterns of CNV, mRNA expression, and protein expression were largely similar between the paired samples for individual patients. However, brain metastases demonstrated increased expression of several activation-specific protein markers in the PI3K/AKT pathway compared with the extracranial metastases.

CONCLUSIONS

These results add to the understanding of the molecular characteristics of melanoma brain metastases and support the rationale for additional testing of the PI3K/AKT pathway as a therapeutic target in these highly aggressive tumors.

Surveillance for brain metastases in patients receiving systemic therapy for advanced melanoma

The objectives of this study were to determine the cumulative incidence and timing of new brain metastases over the course of systemic therapy for metastatic melanoma and to identify prognostic factors for brain metastases. Chemo-naive patients underwent computed tomography or MRI of the brain every 6 weeks. The cumulative incidence of confirmed brain metastases was calculated at 12-week intervals. Univariable and multivariable competing risk regression models were used to assess the association between the development of brain metastases and potential risk factors of interest. Cumulative incidence with competing risk and competing risk regression was used to assess the brain metastasis-free interval from the time of diagnosis of stage IV disease. The clinical characteristics of the 315 patients with brain metastases were compared with those of 370 brain metastasis-free patients. Among patients with brain metastases, a significantly higher proportion had stage M1b and M1c disease at diagnosis compared with stage M1a and a greater proportion had metastatic disease in three or more visceral sites. Significantly shorter brain metastasis-free intervals were found in these patients compared with patients with M1a disease and those with no visceral metastases. More than 80% of the 230 patients who developed brain metastases during systemic therapy had their brain metastases confirmed within 60 weeks from the onset of advanced melanoma. Imaging studies at 12-week intervals for 60 weeks after the diagnosis of advanced melanoma will detect brain metastases in most of the patients who will eventually develop them.

Advances in therapy for melanoma brain metastases

Melanoma cells frequently metastasize to the brain, and approximately 50% of patients with metastatic melanoma develop intracranial disease. Historically, central nervous system dissemination has portended a very poor prognosis. Recent advances in systemic therapies for melanoma, supported by improved local therapy control of brain lesions, have resulted in better median survival for these patients. We review current local and systemic approaches for patients with melanoma brain metastases.

Patterns of response and progression in patients with BRAF-mutant melanoma metastatic to the brain who were treated with dabrafenib

BACKGROUND

Dabrafenib has activity in patients with brain metastases, but little is known of the relative efficacy of treatment within and outside the brain. This study sought to examine the intracranial (IC) and extracranial (EC) patterns of response and progression in patients with active melanoma brain metastases treated with dabrafenib.

METHODS

Clinicopathologic parameters were collected on patients with active brain metastases enrolled in the phase 1 and 2 studies of dabrafenib at a single institution. RECIST (Response Evaluation Criteria In Solid Tumors) response and progression-free survival (PFS) were prospectively assessed by disease site (IC versus EC). Treatments received after disease progression were also assessed.

RESULTS

A total of 23 patients were studied. Response rates were similar in IC (78%) and EC (90%) sites (P = .416). IC and EC response was concordant in 71% of patients. Median site-specific PFS was identical in both IC and EC sites (23.6 weeks, P = .465), and exceeded whole-body PFS determined by RECIST (16.3 weeks). Of 20 patients with progressive disease (PD), 6 had IC PD only, 6 had EC PD only, and 8 had PD in both sites. In those with isolated intracranial PD, 5 of 6 underwent local therapy to the brain and continued on dabrafenib longer than 30 days.

CONCLUSIONS

IC and EC melanoma metastases respond similarly to dabrafenib. There is no dominant site or pattern of disease progression in patients with brain metastases treated with dabrafenib. Salvage local therapy is possible in most patients after IC disease progression, with ongoing dabrafenib treatment possible in a subset of patients.

The use of systemic therapies for the treatment of brain metastases in metastatic melanoma: opportunities and unanswered questions

The development of brain metastases is common in patients with metastatic melanoma and heralds a particularly poor prognosis. The development of the immunological agent ipilimumab and targeted treatments such as the selective BRAF inhibitor vemurafenib have revolutionised the treatment of metastatic disease. Evidence from clinical trials suggest these drugs may be effective in the treatment of brain metastases from melanoma. However efficacy may be limited by a lack of penetration of the blood brain barrier (BBB) and by multi substrate efflux pumps expressed on the BBB. The role and sequencing of radiotherapy, both whole brain and stereotactic radiotherapy, is yet to be determined but combinations of radiotherapy and systemic therapies may further increase the effects of these drugs on brain metastases. Considering the impact of brain metastases on morbidity and mortality in metastatic melanoma, future research into systemic drug therapy for the treatment of brain metastases and improvements in BBB penetrance should be a priority.

High-Dose Interleukin-2 (HD IL-2) Therapy Should Be Considered for Treatment of Patients with Melanoma Brain Metastases

A retrospective review was performed on patients with stable melanoma brain metastases treated with HD IL-2 therapy (720,000 IU/kg per dose intravenously; 14 doses, 2 cycles per course, maximum 2 courses) from January 1999 to June 2011 at Saint Louis University. There were 5 men and 3 women; median age was 52.2 years (26.8–61.1 years). One patient started treatment with lung lesions only (after resection of melanoma brain disease) and experienced partial response. Seven patients had brain metastases at treatment initiation. Median overall survival (mOS) for entire cohort (n = 8) was 8.7 months (2.1 to 19.0 months). All patients with brain metastases at first dose (n = 7) showed progressive disease; mOS was 6.7 months (range 2.1–18.2 months) for this group. Patients received radiosurgery and whole brain radiation before and after HD IL-2 therapy. One patient had symptoms suggestive of neurotoxicity. A history of alcohol abuse was revealed during admission. The patient's symptoms improved with initiation of an alcohol withdrawal protocol. In this analysis, patients with melanoma brain metastases received HD IL-2 without treatment-related mortality. We think that HD IL-2 should be considered as a treatment option in patients with melanoma brain metastases who are otherwise eligible for therapy.

Whole brain radiotherapy for brain metastasis

Whole brain radiotherapy (WBRT) is a mainstay of treatment in patients with both identifiable brain metastases and prophylaxis for microscopic disease. The use of WBRT has decreased somewhat in recent years due to both advances in radiation technology, allowing for a more localized delivery of radiation, and growing concerns regarding the late toxicity profile associated with WBRT. This has prompted the development of several recent and ongoing prospective studies designed to provide Level I evidence to guide optimal treatment approaches for patients with intracranial metastases. In addition to defining the role of WBRT in patients with brain metastases, identifying methods to improve WBRT is an active area of investigation, and can be classified into two general categories: Those designed to decrease the morbidity of WBRT, primarily by reducing late toxicity, and those designed to improve the efficacy of WBRT. Both of these areas of research show diversity and promise, and it seems feasible that in the near future, the efficacy/toxicity ratio may be improved, allowing for a more diverse clinical application of WBRT.

The role of surgical resection in patients with brain metastases

Brain metastasis is a devastating complication of systemic malignancy that affects a considerable number of cancer patients. The appearance of brain metastases is often considered to be a sign of poor prognosis; in patients with brain metastases poor survival time has been reported in the literature. Therefore, treatment of these brain lesions in cancer patients is important for quality of life, providing local tumour control, preventing death from neurological causes, and improving survival, although potentially only in a minority of patients. Surgical resection of brain metastases has been the cornerstone treatment in select patients. Careful patient selection, the use of appropriate surgical techniques, and surgical adjuncts are the major determinants of favourable outcome in patients undergoing resection of brain metastases. In this review, we explain the role of surgical resection in the treatment of patients with brain metastases with consideration of patient selection, surgical techniques and the use of intraoperative adjuncts.

The tumour is not enough or is it? Problems and new concepts in the surgery of cerebral metastases

Cerebral metastases are the most frequent cerebral tumours. Surgery of cerebral metastases plays an indispensible role in a multimodal therapy concept. Conventional white-light, microscopy assisted microsurgical and circumferential stripping of cerebral metastases is neurosurgical standard therapy, but is associated with an extraordinarily high recurrence rate of more than 50% without subsequent whole-brain radiotherapy. Therefore, neurosurgical standard therapy fails to achieve local tumour control in many patients. The present conceptual paper focuses on this issue and discusses the possible causes of the high recurrence rates such as intraoperative dissemination of tumour cells or the lack of sharp delimitation of metastases from the surrounding brain tissue resulting in incomplete resections. Adjuvant whole-brain radiotherapy reduces the risk of local and distant recurrences, but is associated with a well-documented impairment of neurocognitive function. New surgical strategies, such as supramarginal or fluorescence-guided resection, address the possibility of infiltrating tumour parts to achieve more complete resection of cerebral metastases. Supramarginal resection was shown to significantly reduce the risk of a local recurrence and prolongs two-year survival rates. Furthermore, radiosurgery in combination with surgery represents a promising approach.

Mechanisms limiting distribution of the threonine-protein kinase B-RaF(V600E) inhibitor dabrafenib to the brain: implications for the treatment of melanoma brain metastases

Brain metastases are a common cause of death in stage IV metastatic melanoma. Dabrafenib is a BRAF (gene encoding serine/threonine-protein kinase B-Raf) inhibitor that has been developed to selectively target the valine 600 to glutamic acid substitution (BRAF(V600E)), which is commonly found in metastatic melanoma. Clinical trials with dabrafenib have shown encouraging results; however, the central nervous system distribution of dabrafenib remains unknown. Thus, the objective of the current study was to evaluate the brain distribution of dabrafenib in mice, and to see whether active efflux by P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) restricts its delivery across the blood-brain barrier (BBB). In vitro accumulation studies conducted in Madin-Darby canine kidney II cells indicate that dabrafenib is an avid substrate for both P-gp and BCRP. Directional flux studies revealed greater transport in the basolateral to apical direction with corrected efflux ratios greater than 2 for both P-gp and Bcrp1 transfected cell lines. In vivo, the ratio of area under the concentration-time curve (AUC)(brain) to AUC(plasma) (K(p)) of dabrafenib after an i.v. dose (2.5 mg/kg) was 0.023, which increased by 18-fold in Mdr1 a/b(-/-)Bcrp1(-/-) mice to 0.42. Dabrafenib plasma exposure was ∼2-fold greater in Mdr1 a/b(-/-)Bcrp1(-/-) mice as compared with wild-type with an oral dose (25 mg/kg); however, the brain distribution was increased by ~10-fold with a resulting K(p) of 0.25. Further, compared with vemurafenib, another BRAF(V600E) inhibitor, dabrafenib showed greater brain penetration with a similar dose. In conclusion, the dabrafenib brain distribution is limited in an intact BBB model, and the data presented herein may have clinical implications in the prevention and treatment of melanoma brain metastases.

Radiosurgery for melanoma brain metastases in the ipilimumab era and the possibility of longer survival

OBJECT

A prospectively collected cohort of 77 patients who underwent definitive radiosurgery between 2002 and 2010 for melanoma brain metastases was retrospectively reviewed to assess the impact of ipilimumab use and other clinical variables on survival.

METHODS

The authors conducted an institutional review board-approved chart review to assess patient age at the time of brain metastasis diagnosis, sex, primary disease location, initial radiosurgery date, number of metastases treated, performance status, systemic therapy and ipilimumab history, whole-brain radiation therapy (WBRT) use, follow-up duration, and survival at the last follow-up. The Diagnosis-Specific Graded Prognostic Assessment (DSGPA) score was calculated for each patient based on performance status and the number of brain metastases treated.

RESULTS

Thirty-five percent of the patients received ipilimumab. The median survival in this group was 21.3 months, as compared with 4.9 months in patients who did not receive ipilimumab. The 2-year survival rate was 47.2% in the ipilimumab group compared with 19.7% in the nonipilimumab group. The DS-GPA score was the most significant predictor of overall survival, and ipilimumab therapy was also independently associated with an improvement in the hazard for death (p = 0.03).

CONCLUSIONS

The survival of patients with melanoma brain metastases managed with ipilimumab and definitive radiosurgery can exceed the commonly anticipated 4-6 months. Using ipilimumab in a supportive treatment paradigm of radiosurgery for brain oligometastases was associated with an increased median survival from 4.9 to 21.3 months, with a 2-year survival rate of 19.7% versus 47.2%. This association between ipilimumab and prolonged survival remains significant even after adjustment for performance status without an increased need for salvage WBRT.

Dabrafenib in patients with melanoma, untreated brain metastases, and other solid tumours: a phase 1 dose-escalation trial

BACKGROUND

Dabrafenib is an inhibitor of BRAF kinase that is selective for mutant BRAF. We aimed to assess its safety and tolerability and to establish a recommended phase 2 dose in patients with incurable solid tumours, especially those with melanoma and untreated, asymptomatic brain metastases.

METHODS

We undertook a phase 1 trial between May 27, 2009, and March 20, 2012, at eight study centres in Australia and the USA. Eligible patients had incurable solid tumours, were 18 years or older, and had adequate organ function. BRAF mutations were mandatory for inclusion later in the study because of an absence of activity in patients with wild-type BRAF. We used an accelerated dose titration method, with the first dose cohort receiving 12 mg dabrafenib daily in a 21-day cycle. Once doses had been established, we expanded the cohorts to include up to 20 patients. On the basis of initial data, we chose a recommended phase 2 dose. Efficacy at the recommended phase 2 dose was studied in patients with BRAF-mutant tumours, including those with non-Val600Glu mutations, in three cohorts: metastatic melanoma, melanoma with untreated brain metastases, and non-melanoma solid tumours. This study is registered with ClinicalTrials.gov, number NCT00880321.

FINDINGS

We enrolled 184 patients, of whom 156 had metastatic melanoma. The most common treatment-related adverse events of grade 2 or worse were cutaneous squamous-cell carcinoma (20 patients, 11%), fatigue (14, 8%), and pyrexia (11, 6%). Dose reductions were necessary in 13 (7%) patients. No deaths or discontinuations resulted from adverse events, and 140 (76%) patients had no treatment-related adverse events worse than grade 2. Doses were increased to 300 mg twice daily, with no maximum tolerated dose recorded. On the basis of safety, pharmacokinetic, and response data, we selected a recommended phase 2 dose of 150 mg twice daily. At the recommended phase 2 dose in 36 patients with Val600 BRAF-mutant melanoma, responses were reported in 25 (69%, 95% CI 51·9-83·7) and confirmed responses in 18 (50%, 32·9-67·1). 21 (78%, 57·7-91·4) of 27 patients with Val600Glu BRAF-mutant melanoma responded and 15 (56%, 35·3-74·5) had a confirmed response. In Val600 BRAF-mutant melanoma, responses were durable, with 17 patients (47%) on treatment for more than 6 months. Responses were recorded in patients with non-Val600Glu BRAF mutations. In patients with melanoma and untreated brain metastases, nine of ten patients had reductions in size of brain lesions. In 28 patients with BRAF-mutant non-melanoma solid tumours, apparent antitumour activity was noted in a gastrointestinal stromal tumour, papillary thyroid cancers, non-small-cell lung cancer, ovarian cancer, and colorectal cancer.

INTERPRETATION

Dabrafenib is safe in patients with solid tumours, and an active inhibitor of Val600-mutant BRAF with responses noted in patients with melanoma, brain metastases, and other solid tumours.

FUNDING

GlaxoSmithKline.

The role of radiation therapy in the management of metastatic melanoma in the brain

Brain metastasis is common in patients with melanoma and represents a significant cause of morbidity and mortality. There have been no specific randomized trials for patients with melanoma brain metastasis, so treatment is based on management of brain metastasis in general and requires multidisciplinary expertise including radiation oncology, neurosurgery, medical oncology, and palliative care. In this paper, we summarize the prognosis, general management, and the role of radiation therapy in the management of metastatic melanoma in the brain.

Surgical management of brain metastases

In the past 20 years, surgical resection has found an established role in the management of metastatic brain tumors. Several factors, however, make strong evidence-based medicine impossible to provide for all possible patient presentations. These important factors, such as patient variables (eg, age, medical comorbidities, preoperative performance), tumor variables (eg, number, size, location, histology), and primary disease status must be taken into account on a case-by-case basis to guide patient selection and treatment strategy. Although progress has been made to answer some of the major questions in the management of metastatic brain tumors, several important questions remain. Future studies comparing surgery with stereotactic radiosurgery, for example, are needed to delineate patient selection, complications, and outcome for both of these important modalities.

Ipilimumab: showing survival benefit in metastatic melanoma

Ipilimumab is a fully humanized monoclonal antibody to cytotoxic T-lymphocyte-associated antigen 4. Data from preclinical and clinical studies have shown that ipilimumab can cause tumor regression in patients with metastatic melanoma with response rates of 5.8–22%. Phase III trials have demonstrated a benefit in median overall survival in the first-line setting in combination with dacarbazine versus dacarbazine alone (11.2 vs 9.1 months) and in the second-line setting in combination with gp100 versus gp100 alone (10.1 vs 6.4 months). The main toxicities of ipilimumab are immune related, most commonly skin and gastrointestinal. Bowel perforation and treatment-related deaths have occurred, although prompt use of steroids and other immunosuppressive agents can minimize this risk.

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

The incidence of melanoma is rising. The primary initial treatment for melanoma continues to be wide local excision of the primary tumor and affected lymph nodes. Exceptions to wide local excision include cases where surgical excision may be cosmetically disfiguring or associated with increased morbidity and mortality. The role of definitive or adjuvant radiotherapy has largely been relegated to palliative measures because melanoma has been viewed as a prototypical radiotherapy-resistant cancer. However, the emerging clinical and radiobiological data summarized here suggests that many types of effective radiation therapy, such as radiosurgery for melanoma brain metastases, plaque brachytherapy for uveal melanoma, intensity modulated radiotherapy for melanoma of the head and neck, and adjuvant radiotherapy for selected high-risk, node-positive patients can improve outcomes. Similarly, although certain chemotherapeutic agents and biologics have shown limited responses, long-term control for unresectable tumors or disseminated metastatic disease has been rather disappointing. Recently, several powerful new biologics and treatment combinations have yielded new hope for this patient group. The recent identification of several clinically linked melanoma gene mutations involved in mitogen-activated protein kinase (MAPK) pathway such as BRAF, NRAS, and cKIT has breathed new life into the drive to develop more effective therapies. Some of these new therapeutic approaches relate to DNA damage repair inhibitors, cellular immune system activation, and pharmacological cell cycle checkpoint manipulation. Others relate to the investigation of more effective targeting and dosing schedules for underutilized therapeutics, such as radiotherapy. This paper summarizes some of these new findings and attempts to give some context to the renaissance in melanoma therapeutics and the potential role for multimodality regimens, which include certain types of radiotherapy as aids to locoregional control in sensitive tissues.

Stereotactic 125Iodine Brachytherapy for the Treatment of Singular Brain Metastases: Closing a Gap?

BACKGROUND:

Brain metastases represent the most common intracranial tumors and are associated with very poor prognosis.

OBJECTIVE:

To investigate the feasibility, survival, and cerebral disease control of patients with singular brain metastases treated with stereotactic 125iodine brachytherapy (SBT), to identify prognostic factors, and to compare results with other local treatment methods.

METHODS:

Complications, survival (overall and separated by recursive partitioning analysis [RPA] classes), and local and distant disease control were evaluated retrospectively in 90 patients. Prognostic factors were identified by forming subgroups of patients based on age, Karnofsky Performance Status, status of extracranial disease, interval since initial diagnosis, absence/presence of prior whole-brain radiation therapy, localization, morphology, and tumor volume.

RESULTS:

There was no treatment-related mortality, and morbidity was transient and low (3.3%). Median survival was 8.5 months overall and 18.1 months for RPA class 1 patients. After 1 year, the actuarial incidence of local and distant cerebral relapse was 5.4% and 46.4%, respectively. Karnofsky Performance Status ≥ 70 (P &lt; .002), stable systemic disease (P &lt; .02), RPA class 1 (P &lt; .02), and a prolonged (&gt; 12 month) interval between initial diagnosis and SBT (P &lt; .05) significantly improved survival. No significant influence of previous whole-brain radiation therapy on survival or cerebral disease relapse was found.

CONCLUSION:

SBT represents a safe, minimally invasive, and, compared with SRS and microsurgery, a similarly effective local treatment option in terms of survival and cerebral disease control. It allows histological (re-)evaluation and treatment within 1 stereotactic operation. Because it is less restricted by tumor localization or size, it greatly advances local treatment options, and on the basis of its favorable biological irradiation effect, SBT does not limit additional irradiation treatment in the event of disease relapse.

The evolving role of radiation therapy in the management of malignant melanoma

The incidence of melanoma is rising in the United States, leading to an estimated 68,720 new diagnoses and 8,650 deaths annually. The natural history involves metastases to lymph nodes, lung, liver, brain, and often to other sites. Primary treatment for melanoma is surgical excision of the primary tumor and affected lymph nodes. The role of adjuvant or definitive radiation therapy in the treatment of melanoma remains controversial, because melanoma has traditionally been viewed as a prototypical radioresistant cancer. However, recent studies suggest that under certain clinical circumstances, there may be a significant role for radiation therapy in melanoma treatment. Stereotactic radiosurgery for brain metastases has shown effective local control. High dose per fraction radiation therapy has been associated with a lower rate of locoregional recurrence of sinonasal melanoma. Plaque brachytherapy has evolved into a promising alternative to enucleation at the expense of moderate reduction in visual acuity. Adjuvant radiation therapy following lymphadenectomy in node-positive melanoma prevents local and regional recurrence. The newer clinical data along with emerging radiobiological data indicate that radiotherapy is likely to play a greater role in melanoma management and should be considered as a treatment option.

Surgical management of melanoma brain metastases in patients treated with immunotherapy

OBJECT

Despite the increasing use of immunotherapy in the treatment of metastatic melanoma, the effects of this therapy on the management of patients with associated brain metastases are not completely defined. The authors undertook this study to determine the effectiveness of resection and the effects of immunotherapy on brain metastasis management.

METHODS

The authors analyzed data pertaining to consecutive patients with metastatic melanoma treated with immunotherapy within 3 months of discovery of brain metastases that were surgically resected.

RESULTS

Forty-one patients (median age 44.4 years, range 19.2-63.1 years) underwent resection of 53 brain metastases (median number of metastases 1, range 1-4). The median metastasis volume was 2.5 cm(3). Fifteen patients underwent whole-brain radiation therapy (WBRT) and 26 patients did not. Duration of survival from brain metastasis diagnosis was not significantly different between patients who received WBRT (mean 24.9 months) and those who did not (mean 23.3 months) (p > 0.05). Local and distant brain recurrence rates were not statistically different between the WBRT (7.1% and 28.6%, respectively) and non-WBRT (7.7% and 41.0%) groups for the duration of follow-up (p > 0.05). An objective systemic response to immunotherapy was associated with increased duration of survival (p < 0.05).

CONCLUSIONS

Resection of melanoma brain metastases in patients treated with immunotherapy provides excellent local control with low morbidity. An objective response to systemic immunotherapy is associated with a prolonged survival in patients who have undergone resection of melanoma brain metastases. Moreover, adjuvant WBRT in melanoma immunotherapy patients with limited metastatic disease to the brain does not appear to provide a significant survival benefit.