Impact of pemetrexed on intracranial disease control and radiation necrosis in patients with brain metastases from non-small cell lung cancer receiving stereotactic radiation

Minimizing Intracranial Disease Before Stereotactic Radiation in Single or Solitary Brain Metastases

BACKGROUND AND OBJECTIVES

Stereotactic radiotherapy (SRT) in multiple fractions (typically ≤5) can effectively treat a wide range of brain metastases, including those less suitable for single-fraction stereotactic radiosurgery (SRS). Prior prospective studies on surgical resection with stereotactic radiation have focused exclusively on SRS, and retrospective studies have shown equivocal results regarding whether surgery is associated with improved outcomes compared with SRT alone. We compared resection with postoperative cavity SRT or SRS to SRT alone in patients with 1 brain metastasis, while including patients receiving SRS alone as an additional reference group.

METHODS

We studied 716 patients in a retrospective, single-institution cohort diagnosed with single or solitary brain metastases from 2007 to 2020. Patients receiving whole-brain radiotherapy were excluded. Cox proportional hazards models were constructed for overall survival and additional intracranial outcomes.

RESULTS

After adjustment for potential confounders, surgery with cavity SRT/SRS was associated with decreased all-cause mortality (hazard ratio [HR]: 0.39, 95% CI [0.27-0.57], P = 1.52 × 10 -6 ) compared with SRT alone, along with lower risk of neurological death attributable to intracranial tumor progression (HR: 0.46, 95% CI [0.22-0.94], P = 3.32 × 10 -2 ) and radiation necrosis (HR: 0.15, 95% CI [0.06-0.36], P = 3.28 × 10 -5 ). Surgery with cavity SRS was also associated with decreased all-cause mortality (HR: 0.52, 95% CI [0.35-0.78], P = 1.46 × 10 -3 ), neurological death (HR: 0.30, 95% CI [0.10-0.88], P = 2.88 × 10 -2 ), and radiation necrosis (HR: 0.14, 95% CI [0.03-0.74], P = 2.07 × 10 -2 ) compared with SRS alone. Surgery was associated with lower risk of all-cause mortality and neurological death in cardinality-matched subsets of the cohort. Among surgical patients, gross total resection was associated with extended overall survival (HR: 0.62, 95% CI [0.40-0.98], P = 4.02 × 10 -2 ) along with lower risk of neurological death (HR: 0.31, 95% CI [0.17-0.57], P = 1.84 × 10 -4 ) and local failure (HR: 0.34, 95% CI [0.16-0.75], P = 7.08 × 10 -3 ).

CONCLUSION

In patients with 1 brain metastasis, minimizing intracranial disease specifically before stereotactic radiation is associated with improved oncologic outcomes.

Novel Mechanisms and Future Opportunities for the Management of Radiation Necrosis in Patients Treated for Brain Metastases in the Era of Immunotherapy

Radiation necrosis, also known as treatment-induced necrosis, has emerged as an important adverse effect following stereotactic radiotherapy (SRS) for brain metastases. The improved survival of patients with brain metastases and increased use of combined systemic therapy and SRS have contributed to a growing incidence of necrosis. The cyclic GMP-AMP (cGAMP) synthase (cGAS) and stimulator of interferon genes (STING) pathway (cGAS-STING) represents a key biological mechanism linking radiation-induced DNA damage to pro-inflammatory effects and innate immunity. By recognizing cytosolic double-stranded DNA, cGAS induces a signaling cascade that results in the upregulation of type 1 interferons and dendritic cell activation. This pathway could play a key role in the pathogenesis of necrosis and provides attractive targets for therapeutic development. Immunotherapy and other novel systemic agents may potentiate activation of cGAS-STING signaling following radiotherapy and increase necrosis risk. Advancements in dosimetric strategies, novel imaging modalities, artificial intelligence, and circulating biomarkers could improve the management of necrosis. This review provides new insights into the pathophysiology of necrosis and synthesizes our current understanding regarding the diagnosis, risk factors, and management options of necrosis while highlighting novel avenues for discovery.

Brain metastases: A Society for Neuro-Oncology (SNO) consensus review on current management and future directions

Brain metastases occur commonly in patients with advanced solid malignancies. Yet, less is known about brain metastases than cancer-related entities of similar incidence. Advances in oncologic care have heightened the importance of intracranial management. Here, in this consensus review supported by the Society for Neuro-Oncology (SNO), we review the landscape of brain metastases with particular attention to management approaches and ongoing efforts with potential to shape future paradigms of care. Each coauthor carried an area of expertise within the field of brain metastases and initially composed, edited, or reviewed their specific subsection of interest. After each subsection was accordingly written, multiple drafts of the manuscript were circulated to the entire list of authors for group discussion and feedback. The hope is that the these consensus guidelines will accelerate progress in the understanding and management of patients with brain metastases, and highlight key areas in need of further exploration that will lead to dedicated trials and other research investigations designed to advance the field.

[Expert Consensus on the Treatment of Antiangiogenic Agents for Radiation Brain Necrosis]

Vascular damage is followed by vascular endothelial growth factor (VEGF) expression at high levels, which is an important mechanism for cerebral radiation necrosis (CRN) development. Antiangiogenic agents (Bevacizumab) alleviates brain edema symptoms caused by CRN through inhibiting VEGF and acting on vascular tissue around the brain necrosis area. Many studies have confirmed that Bevacizumab effectively relieves symptoms caused by brain necrosis, improves patients' performance status and brain necrosis imaging. Considering that the efficacy of antiangiogenic therapy is mainly related to the duration of drug action, low-dose antiangiogenic agents can achieve favorable efficacy. Prevention is the best treatment. The occurrence of CRN is associated with tumor-related factors and treatment-related factors. By controlling these factors, CRN can be effectively prevented.
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Advances in the Diagnosis and Treatment of Leptomeningeal Disease

PURPOSE OF REVIEW

Leptomeningeal disease (LMD) is a rare, late complication of systemic cancer and is associated with significant neurological morbidity and high mortality. Here we provide an overview of this condition, summarizing key recent research findings and clinical practice trends in its diagnosis and treatment. We also review current clinical trials for LMD.

RECENT FINDINGS

Improved molecular diagnostic tools are in development to enable more sensitive detection of LMD, including circulating tumor cells and circulating tumor DNA. The use of targeted and CNS-penetrant therapeutics has shown survival improvements with tyrosine kinase inhibitors, antibody-drug conjugates, and select chemotherapy. However, these studies have primarily been phase I/II and retrospective analyses. There remains a dearth of clinical trials that include LMD patients. The combination of patient-specific molecular information and novel therapeutic approaches holds significant promise for improving outcomes in patients with LMD.

Integration of Systemic Therapy and Stereotactic Radiosurgery for Brain Metastases

Simple Summary

In the multi-modal treatment of brain metastasis (BM), the role of systemic therapy has undergone a recent revolution. Due to the development of multiple agents with modest central nervous system penetration of the blood-brain barrier, targeted therapies and immune checkpoint inhibitors are increasingly being utilized alone or in combination with radiation therapy. However, the adoption of sequential or concurrent strategies varies considerably, and treatment strategies employed in clinical practice have rapidly outpaced evidence development. Therefore, this review critically analyzes the data regarding combinatorial approaches for a variety of systemic therapeutics with stereotactic radiosurgery and provides an overview of ongoing clinical trials.

Abstract

Brain metastasis (BM) represents a common complication of cancer, and in the modern era requires multi-modal management approaches and multi-disciplinary care. Traditionally, due to the limited efficacy of cytotoxic chemotherapy, treatment strategies are focused on local treatments alone, such as whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and resection. However, the increased availability of molecular-based therapies with central nervous system (CNS) penetration now permits the individualized selection of tailored systemic therapies to be used alongside local treatments. Moreover, the introduction of immune checkpoint inhibitors (ICIs), with demonstrated CNS activity has further revolutionized the management of BM patients. The rapid introduction of these cancer therapeutics into clinical practice, however, has led to a significant dearth in the published literature about the optimal timing, sequencing, and combination of these systemic therapies along with SRS. This manuscript reviews the impact of tumor biology and molecular profiles on the management paradigm for BM patients and critically analyzes the current landscape of SRS, with a specific focus on integration with systemic therapy. We also discuss emerging treatment strategies combining SRS and ICIs, the impact of timing and the sequencing of these therapies around SRS, the effect of corticosteroids, and review post-treatment imaging findings, including pseudo-progression and radiation necrosis.

Necrosis of the optic nerve and chiasm with safe radiation doses: Report of two rare cases

INTRODUCTION

Radiation-induced optic neuropathy (RION) is still a devastating complication of brain and skull base radiation that has no effective treatment up until today, thus uttermost caution must be taken in treating patients that brain radiotherapy is needed. We present two cases of RION that happened in seemingly safe radiation doses.

CASE DESCRIPTION

A 48-year-old female with a history of pleomorphic pituitary adenoma developed bilateral and painless loss of vision 10 months after radiation to the brain; the total radiation dose was 45 Gy in 25 fractions and no other risk factors of RION were found. Magnetic resonance imaging of the brain depicted bilateral prechiasmatic optic nerve enhancement with involvement of the optic chiasm. Treatment with high doses of corticosteroids was unsuccessful. A 62-year-old female with a history of lung adenocarcinoma and brain metastases presented with a 1-month history of decreased vision in both eyes. He had undergone whole-brain radiotherapy with a total dose of 30 Gy over 10 fractions and concurrent chemotherapy with cisplatin and pemetrexed. Brain magnetic resonance imaging (MRI) with contrast showed bilateral intracranial optic nerve enhancement.

CONCLUSIONS

This is the second case report of RION in a patient with a history of brain radiotherapy and concurrent chemotherapy with pemetrexed. History of chiasmal compression, concurrent use of chemotherapeutic agents, and high fraction size (despite the safety of total radiation dose) were possible contributing risk factors to develop RION in our cases. Hence, adjusting the radiation dose according to the presence of these risk factors is recommended.

Safety of radiosurgery concurrent with systemic therapy (chemotherapy, targeted therapy, and/or immunotherapy) in brain metastases: a systematic review

Stereotactic radiosurgery (SRS) is a standard option for brain metastases (BM). There is lack of consensus when patients have a systemic treatment, if a washout is necessary. The aim of this review is to analyze the toxicity of SRS when it is concurrent with chemotherapies, immunotherapy, and/or targeted therapies. From Medline and Embase databases, we searched for English literature published up to April 2020 according to the PRISMA guidelines, using for key words the list of the main systemic therapies currently in use And "radiosurgery," "SRS," "GKRS," "Gamma Knife," "toxicity," "ARE," "radiation necrosis," "safety," "brain metastases." Studies reporting safety or toxicity with SRS concurrent with systemic treatment for BM were included. Of 852 abstracts recorded, 77 were included. The main cancers were melanoma, lung, breast, and renal carcinoma. These studies cumulate 6384 patients. The median SRS dose prescription was 20 Gy [12-30] .For some, they compared a concurrent arm with a non-concurrent or a SRS-alone arm. There were no skin toxicities, no clearly increased rate of bleeding, or radiation necrosis with significant clinical impact. SRS combined with systemic therapy appears to be safe, allowing the continuation of treatment when brain SRS is considered.

A modified recursive partitioning analysis for predicting overall survival in patients with non-small cell lung cancer and central nervous system metastases

Background

Non-small cell lung cancer (NSCLC) is a major cause of brain metastases. Nonetheless, patients with central nervous system (CNS) spread are poorly represented in clinical trials. We sought to evaluate the overall survival (OS) of patients with NSCLC and CNS metastases.

Methods

Patients with NSCLC and CNS metastases treated at A. C. Camargo Cancer Center from January 2007 to December 2017 were selected. The primary endpoint was OS following the diagnosis of CNS metastasis. The Kaplan-Meier method was applied to calculate OS. Prognostic factors were assessed by the Cox Proportional Hazards model. As an exploratory analysis, a survival tree was generated based upon the two most statistically significant variables in the multivariate model and one additional clinically meaningful variable.

Results

In total, 311 patients were included. Median OS was 10.3 months (95% CI, 8.7-13.1 months). ECOG performance status 2-4 (HR 2.12; 95% CI, 1.40-3.20; P<0.01) and the absence of a driver mutation (HR 3.30; 95% CI, 1.85-5.90; P<0.01) were strongly associated with worse OS. A Modified Recursive Partitioning Analysis (mRPA) was developed based on the curves generated by the survival tree. mRPA stratified our cohort in four subgroups with significantly different OS (3.1 to 43 months) and it outperformed both RPA and GPA in predicting OS in our population.

Conclusions

OS in our cohort was better than previously reported. However, prognosis is widely variable and is mostly dictated by performance status and the presence of a driver mutation.

Breast cancer subtype and intracranial recurrence patterns after brain-directed radiation for brain metastases

PURPOSE

Brain metastases from breast cancer are frequently managed with brain-directed radiation but the impact of subtype on intracranial recurrence patterns after radiation has not been well-described. We investigated intracranial recurrence patterns of brain metastases from breast cancer after brain-directed radiation to facilitate subtype-specific management paradigms.

METHODS

We retrospectively analyzed 349 patients with newly diagnosed brain metastases from breast cancer treated with brain-directed radiation at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2000 and 2015. Patients were stratified by subtype: hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-), HER2+ positive (HER2+), or triple-negative breast cancer (TNBC). A per-metastasis assessment was conducted. Time-to-event analyses were conducted using multivariable Cox regression.

RESULTS

Of the 349 patients, 116 had HR+/HER2- subtype, 164 had HER2+ subtype, and 69 harbored TNBC. Relative to HR+/HER2- subtype, local recurrence was greater in HER2+ metastases (HR 3.20, 95% CI 1.78-5.75, p < 0.001), while patients with TNBC demonstrated higher rates of new brain metastases after initial treatment (HR 3.16, 95% CI 1.99-5.02, p < 0.001) and shorter time to salvage whole brain radiation (WBRT) (HR 3.79, 95% CI 1.36-10.56, p = 0.01) and salvage stereotactic radiation (HR 1.86, 95% CI 1.11-3.10, p = 0.02).

CONCLUSIONS

We identified a strong association between breast cancer subtype and intracranial recurrence patterns after brain-directed radiation, particularly local progression for HER2+ and distant progression for TNBC patients. If validated, the poorer local control in HER2+ brain metastases may support evaluation of novel local therapy-based approaches, while the increased distant recurrence in TNBC suggests the need for improved systemic therapy and earlier utilization of WBRT.

Local control after brain-directed radiation in patients with cystic versus solid brain metastases

PURPOSE

Brain metastases can be radiographically cystic or solid. Cystic metastases are associated with a greater intracranial disease burden and poorer oncologic outcomes, but the impact of cystic versus solid appearance on local control after radiation remains unknown. We investigated whether cystic versus solid nature is predictive of local control after management with stereotactic or whole brain radiation (WBRT) and whether the radiation modality utilized is an effect modifier.

METHODS

We identified 859 patients with 2211 newly-diagnosed brain metastases managed with upfront stereotactic radiation or WBRT without preceding resection/aspiration at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2000 and 2015. Multivariable Cox regression with an interaction term and sandwich covariance matrix was used to quantify local failure.

RESULTS

Cystic lesions were more likely to recur than solid ones when managed with stereotactic radiation (HR 2.33, 95% CI 1.32-4.10, p = 0.004) but not WBRT (HR 0.92, 95% CI 0.62-1.36, p = 0.67), p-interaction = 0.007. 1 year local control rates for cystic versus solid metastases treated with stereotactic radiation were 75% versus 88%, respectively; estimates with WBRT were 76% versus 76%, respectively. However, no significant differences were noted between the two cohorts in post-radiation outcomes including all-cause mortality and neurologic death (p > 0.05).

CONCLUSIONS

Among patients with brain metastases, stereotactic radiation yields improved local control and less morbidity than WBRT, and consequently for many patients the cystic versus solid designation does not impact treatment selection. However, our results suggest that in patients with a large number of cystic brain metastases, a lower threshold to consider WBRT, as opposed to stereotactic radiation, should be employed. If our results can be confirmed, further investigation into the underlying mechanism(s) would be warranted.

Effect of pemetrexed on brain metastases from nonsmall cell lung cancer with wild-type and unknown EGFR status

We aimed to evaluate the effectiveness of pemetrexed-based chemotherapy in wild-type nonsmall-cell lung cancer (NSCLC) patients with brain metastases (BM). Brain metastases are a common cause of mortality in NSCLC patients. For epidermal growth factor receptor (EGFR) wild-type patients, therapeutic options for BM are even limited. Pemetrexed-based therapy is a standard care for patients with EGFR-negative, nonsquamous NSCLC. Besides local therapy, pemetrexed is the preferred chemotherapy for wild-type BM patients, but the efficacy is uncertain.We retrospectively studied 138 NSCLC patients with BM whose EGFR status were unknown or wild-type. All patients received first-line pemetrexed-based chemotherapy from 2010 to 2015. Forty-six of 89 patients with unknown EGFR status were treated with EGFR TKIs after progression.Among the 138 patients, 49 (35.5%) were EGFR wild-type and 89 (64.5%) were unknown EGFR status. The median overall survival (OS), and the median intracranial progression-free survival (iPFS) was 21.0 months, 9.5 months, respectively. Patients who received more than 4 cycles of chemotherapy had significantly longer OS than those who received 3 to 4 cycles (Mantel-Byar X-squared = 6.65, P = .001). In the EGFR wild-type group, the median OS, and the median iPFS was 17.7 months, 7.6 months, respectively. And patients treated with pemetrexed plus platinum tended to have a longer OS than those who were treated with pemetrexed alone (P = .078). In the subgroup with unknown EGFR status, we noted a statistically significant improvement in OS for the patients who received EGFR tyrosine kinase inhibitors (TKIs) after progression of 29 months compared to 20.3 months of the EGFR TKIs naïve arm (P = .027).Pemetrexed shows an ideal effectiveness in EGFR wild-type and unknown status NSCLC patients with BM, and has a favorable control on brain localizations. EGFR wild-type patients can significantly benefit from pemetrexed continuation maintenance.