PURPOSE: Conventional wisdom has rendered patients with brain metastases ineligible for clinical trials for fear that poor survival could mask the benefit of otherwise promising treatments. Our group previously published the diagnosis-specific Graded Prognostic Assessment (GPA). Updates with larger contemporary cohorts using molecular markers and newly identified prognostic factors have been published. The purposes of this work are to present all the updated indices in a single report to guide treatment choice, stratify research, and define an eligibility quotient to expand eligibility. METHODS: A multi-institutional database of 6,984 patients with newly diagnosed brain metastases underwent multivariable analyses of prognostic factors and treatments associated with survival for each primary site. Significant factors were used to define the updated GPA. GPAs of 4.0 and 0.0 correlate with the best and worst prognoses, respectively. RESULTS: Significant prognostic factors varied by diagnosis and new prognostic factors were identified. Those factors were incorporated into the updated GPA with robust separation ( P < .01) between subgroups. Survival has improved, but varies widely by GPA for patients with non–small-cell lung, breast, melanoma, GI, and renal cancer with brain metastases from 7-47 months, 3-36 months, 5-34 months, 3-17 months, and 4-35 months, respectively. CONCLUSION: Median survival varies widely and our ability to estimate survival for patients with brain metastases has improved. The updated GPA (available free at brainmetgpa.com) provides an accurate tool with which to estimate survival, individualize treatment, and stratify clinical trials. Instead of excluding patients with brain metastases, enrollment should be encouraged and those trials should be stratified by the GPA to ensure those trials make appropriate comparisons. Furthermore, we recommend the expansion of eligibility to allow for the enrollment of patients with previously treated brain metastases who have a 50% or greater probability of an additional year of survival (eligibility quotient > 0.50).

Despite advances in understanding of the molecular pathogenesis of glioma, outcomes remain dismal. Developing successful treatments for glioma requires faithful in vivo disease modeling and rigorous preclinical testing. Murine models, including xenograft, syngeneic, and genetically engineered models, are used to study glioma-genesis, identify methods of tumor progression, and test novel treatment strategies. Since the discovery of highly recurrent isocitrate dehydrogenase (IDH) mutations in lower-grade gliomas, there is increasing emphasis on effective modeling of IDH mutant brain tumors. Improvements in preclinical models that capture the phenotypic and molecular heterogeneity of gliomas are critical for the development of effective new therapies. Herein, we explore the current status, advancements, and challenges with contemporary murine glioma models.

The emergence of three-dimensional human organoids has opened the door for the development of patient-derived cancer organoid (PDO) models, which closely recapitulate parental tumor tissue. The mainstays of preclinical cancer modeling include in vitro cell lines and patient-derived xenografts, but these models lack the cellular heterogeneity seen in human tumors. Moreover, xenograft establishment is resource and time intensive, rendering these models difficult to use to inform clinical trials and decisions. PDOs, however, can be created efficiently and retain tumor-specific properties such as cellular heterogeneity, cell–cell and cell–stroma interactions, the tumor microenvironment, and therapeutic responsiveness. PDO models and drug-screening protocols have been described for several solid tumors and, more recently, for gliomas. Since PDOs can be developed in clinically relevant time frames and share many characteristics of parent tumors, they may enhance the ability to provide precision oncologic care for patients. This review explores the current literature on cancer organoids, highlighting the history of PDO development, organoid models of glioma, and potential clinical applications of PDOs.

PURPOSE: Stereotactic radiation (SRS/SRT) as opposed to whole-brain radiation (WBRT) represents the standard of care for patients with a limited number of brain metastases given the relatively favorable toxicity profile associated with stereotactic treatment. However, in patients with small cell lung cancer (SCLC), WBRT remains standard because of a lack of prospective data supporting SRS/SRT and concerns related to intracranial progression and neurologic death when WBRT is omitted. We conducted a single-arm, multicenter, phase II trial of SRS/SRT in patients with SCLC and 1-10 brain metastases to assess neurologic death rates relative to historical controls managed with WBRT (ClinicalTrials.gov identifier: NCT03391362 ). METHODS: Patients were eligible if they had SCLC or an extrathoracic small cell primary and 1-10 brain metastases. Previous brain-directed radiation including prophylactic cranial irradiation was not permitted. Neurologic death was defined as marked, progressive, radiographic brain progression accompanied by corresponding neurologic symptomatology without systemic disease progression or systemic symptoms of a life-threatening nature. Close imaging-based surveillance of the brain post-SRS/SRT was used. RESULTS: Between February 2018 and April 2023, 100 patients were enrolled. The median number of brain metastases was 2 (IQR, 1-4; range, 1-10). The median overall survival was 10.2 months; only 22% of patients required salvage WBRT. In total, 20 neurologic deaths were observed, relative to 64 non-neurologic deaths. The neurologic death rate at 1 year was 11.0% (95% CI, 5.8 to 18.1); the historical rate in patients managed with WBRT was 17.5%. CONCLUSION: Our prospective, multi-institutional study demonstrated low rates of neurologic death when SRS/SRT as opposed to WBRT is used in patients with SCLC and 1-10 brain metastases who are surveilled closely post-treatment, supporting the utility of stereotactic approaches in this population.