Treatment for Brain Metastases: ASCO-SNO-ASTRO Guideline

The Blood-Brain Barrier: Implications for Experimental Cancer Therapeutics

The blood-brain barrier is critically important for the treatment of both primary and metastatic cancers of the central nervous system (CNS). Clinical outcomes for patients with primary CNS tumors are poor and have not significantly improved in decades. As treatments for patients with extracranial solid tumors improve, the incidence of CNS metastases is on the rise due to suboptimal CNS exposure of otherwise systemically active agents. Despite state-of-the art surgical care and increasingly precise radiation therapy, clinical progress is limited by the ability to deliver an effective dose of a therapeutic agent to all cancerous cells. Given the tremendous heterogeneity of CNS cancers, both across cancer subtypes and within a single tumor, and the range of diverse therapies under investigation, a nuanced examination of CNS drug exposure is needed. With a shared goal, common vocabulary, and interdisciplinary collaboration, the field is poised for renewed progress in the treatment of CNS cancers.

Brain metastases from hepatopancreatobiliary malignancies

While colorectal and gastroesophageal cancer represent the two gastrointestinal (GI) tumor entities with the highest incidence of brain metastatic (BM) disease, data on the clinical course of BM patients from hepatopancreatobiliary malignancies are rare. Patients with cholangiocarcinoma (CCA), hepatocellular carcinoma (HCC), pancreatic ductal adenocarcinoma (PDAC) and gastroenteropancreatic neuroendocrine neoplasms (GEP NEN). Treated for BM between 1991 and 2017 at an academic care center were included. Brain metastases-free survival (BMFS) was defined as interval from first diagnosis until BM development. Overall survival (OS) was defined as interval from diagnosis of BM until death or last date of follow-up. Outcome was correlated with clinical and treatment factors. 29 patients from overall 6102 patients (0.6%) included in the Vienna Brain Metastasis Registry presented with BM from hepatopancreatobiliary primaries including 9 (31.0%) with CCA, 10 (34.5%) with HCC, 7 (24.1%) with PDAC and 3 (10.3%) with GEP NEN as primary tumor. Median BMFS was 21, 12, 14 and 7 months and median OS 4, 4, 6 and 4 months, respectively. Karnofsky Performance Status (KPS) below 80% (p = 0.08), age above 60 years (p = 0.10) and leptomeningeal carcinomatosis (LC) (p = 0.09) diagnosed concomitant to solid BM showed an inverse association with median OS (Cox proportional hazards model). In this cohort of patients with BM from hepatopancreatobiliary tumor entities, prognosis was shown to be very limited. Performance status, age and diagnosis of LC were identified as negative prognostic factors.

Poor Karnofsky performance status is not a contraindication for neurosurgical resection in patients with lung cancer brain metastases: a multicenter, retrospective PSM-IPTW cohort study

BACKGOUND

Neurosurgical resection is a standard local treatment for lung cancer brain metastases (BMs). This study aims to investigate whether neurosurgical resection provides survival benefit in lung cancer BMs with poor KPS.

MATERIALS AND METHODS

This multicenter retrospective study included 386 lung cancer BMs with pretreatment KPS ≤ 70 among a total of 1177 lung cancer BMs treated at three centers from August 2010 to July 2021. Data analysis was performed from July to September 2022. Inverse probability of treatment weighting (IPTW) and propensity scores matching (PSM) based on propensity scoring were used to minimize bias. The main outcome was overall survival (OS) after diagnosis of BMs. Risk factors of OS were estimated using Cox proportional hazards regression models. All Characteristics were included in the multivariate Cox regression.

RESULTS

386 patients with pretreatment KPS ≤ 70 were included (age mean [SD], 57.85 [10.36] years; KPS mean [SD], 60.91 [10.11]). Among them, 111 patients received neurosurgical resection, while 275 patients did not. Baseline characteristics were balanced between groups after IPTW or PSM. Neurosurgical resection was associated with significantly better prognosis in unadjusted multivariate COX analysis (hazard ratio [HR]: 0.68, 95% confidence interval [CI]: 0.51-0.91, P = 0.01), and PSM-adjusted multivariate COX analysis (HR: 0.61, 95%CI: 0.39-0.94, P = 0.03), IPTW-adjusted multivariate COX analysis (HR: 0.58, 95%CI: 0.40-0.84, P = 0.004). OS was significantly longer in neurosurgical resection group compared with non-surgical resection group according to unadjusted data (Median OS, surgery vs non-surgery, 14.7 vs 12.5 months, P = 0.01), PSM-adjusted data (median OS, 17.7 vs 12.3 months, P < 0.01) and IPTW-adjusted data (median OS, 17.7 vs 12.5 months, P < 0.01).

CONCLUSIONS

Neurosurgical resection was associated with improved survival in patients with lung cancer BMs with poor KPS, suggesting that poor KPS is not a contraindication for neurosurgical resection in these patients.

Time interval from diagnosis to treatment of brain metastases with stereotactic radiosurgery is not associated with radionecrosis or local failure

Introduction

Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear.

Methods

This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher’s exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure.

Results

A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure.

Discussion

An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.

What if: A retrospective reconstruction of resection cavity stereotactic radiosurgery to mimic neoadjuvant stereotactic radiosurgery

Introduction

Neoadjuvant stereotactic radiosurgery (NaSRS) of brain metastases has gained importance, but it is not routinely performed. While awaiting the results of prospective studies, we aimed to analyze the changes in the volume of brain metastases irradiated pre- and postoperatively and the resulting dosimetric effects on normal brain tissue (NBT).

Methods

We identified patients treated with SRS at our institution to compare hypothetical preoperative gross tumor and planning target volumes (pre-GTV and pre-PTV) with original postoperative resection cavity volumes (post-GTV and post-PTV) as well as with a standardized-hypothetical PTV with 2.0 mm margin. We used Pearson correlation to assess the association between the GTV and PTV changes with the pre-GTV. A multiple linear regression analysis was established to predict the GTV change. Hypothetical planning for the selected cases was created to assess the volume effect on the NBT exposure. We performed a literature review on NaSRS and searched for ongoing prospective trials.

Results

We included 30 patients in the analysis. The pre-/post-GTV and pre-/post-PTV did not differ significantly. We observed a negative correlation between pre-GTV and GTV-change, which was also a predictor of volume change in the regression analysis, in terms of a larger volume change for a smaller pre-GTV. In total, 62.5% of cases with an enlargement greater than 5.0 cm3 were smaller tumors (pre-GTV < 15.0 cm3), whereas larger tumors greater than 25.0 cm3 showed only a decrease in post-GTV. Hypothetical planning for the selected cases to evaluate the volume effect resulted in a median NBT exposure of only 67.6% (range: 33.2-84.5%) relative to the dose received by the NBT in the postoperative SRS setting. Nine published studies and twenty ongoing studies are listed as an overview.

Conclusion

Patients with smaller brain metastases may have a higher risk of volume increase when irradiated postoperatively. Target volume delineation is of great importance because the PTV directly affects the exposure of NBT, but it is a challenge when contouring resection cavities. Further studies should identify patients at risk of relevant volume increase to be preferably treated with NaSRS in routine practice. Ongoing clinical trials will evaluate additional benefits of NaSRS.

Multiple craniotomies in a single surgery - the resection of scattered brain metastases

Patients with brain metastases (BM), who can benefit from resection of multiple scattered lesions, often will not be offered a procedure involving multiple craniotomies in one session due to the overall poor prognosis. However, carefully selected candidates may well benefit from the resection of multiple lesions using multiple craniotomies through a significantly shortened hospital stay, aggressive decompression, and rapid eligibility for adjuvant therapies. In this retrospective analysis, the records of patients, who were treated for multiple BM using one surgical session involving multiple craniotomies, were reviewed. A group of patients with multiple BM, whose surgery only involved one craniotomy, were assigned to a control group. Clinical and surgical characteristics, preoperative and postoperative Karnofsky Performance Scale (KPS), complication rate, preoperative tumor size, number of lesions, number of craniotomies, skin incisions, and intraoperative repositioning of patients were recorded. Thirty-three patients were included in the multiple-craniotomy group. Thirty patients underwent two craniotomies, while three cases involved three craniotomies. Seven patients (21%) were intraoperatively repositioned from a prone to a supine position, which required an average of 23.3 ± 9.3 min from wound closure to the following skin incision. Thirty-six patients with multiple BM and matching characteristics, who received only one craniotomy for the dominant lesion, served as the control group. No difference was detected in postoperative KPS (p = 0.269), complication rate (p = 0.612), rate of new postoperative neurological deficits (p = 0.278), length of intensive care unit (ICU) (p = 0.991), and hospital stay (p = 0.913). There was a significant difference in average preoperative tumor size (p = 0.002), duration of surgery (p < 0.001), and extent of resection (p = 0.002). In the age of personalized medicine, selected patient may benefit from a single surgery for BM using multiple craniotomies. This study shows no significant increase of the perioperative complication rate for surgeries with multiple craniotomies.

Gamma Knife radiosurgery for gynecologic metastases to the brain: Analysis of pathology, survival, and tumor control

OBJECTIVE

This study aims to evaluate the efficacy of stereotactic radiosurgery (SRS) in improving health outcomes of patients with gynecologic brain metastases.

METHODS

Patients with gynecologic metastases treated with SRS from 2008 to 2020 were retrospectively reviewed. The median age at SRS was 63 years old (cervical 45.5, endometrial 65.5, ovarian 61). The median number of tumors was 3 (range 1-27), and cumulative tumor volume was 2.33 cc (range 0.03-45.63). Median margin dose prescribed was 16 Gy (range 14 Gy - 20 Gy). The median 12 Gy volume was 7.30 cc (range 0.21-74.14 cc). Outcome variables included overall survival (OS) after SRS, local tumor control (LTC), distant tumor control, and adverse radiation effect (ARE).

RESULTS

Fifty patients (4 cervical, 25 endometrial, and 21 ovarian cancer) were identified. The OS at 6 and 12 months after SRS was 48%, and 44%, respectively. Eight patients (16%) died from CNS disease progression. The number of brain metastases (p = 0.011) and the Karnofsky Performance Scale (KPS) ≥ 70 (p = 0.020) were significant predictors of OS. LTC rate at 6 and 12 months were 92%, and 87%, respectively. Margin dose ≥16Gy correlated with significantly better local tumor control (p = 0.0001) without increased risk of ARE (p = 0.055). The risk of developing new metastases at 6 and 12 months were 12% and 24% respectively. SRS-induced ARE events occurred in 7 patients.

CONCLUSION

Intracranial metastases from gynecologic malignancy can be effectively treated using SRS with low risk of neurotoxicity. Margin dose ≥16Gy can provide significantly better tumor control. Repeat SRS can be utilized to treat new metastases while avoiding the potential cognitive symptoms associated with WBRT.

Hypofractionated stereotactic radiosurgery (HSRS) as a salvage treatment for brain metastases failing prior stereotactic radiosurgery (SRS)

INTRODUCTION

Various treatment options exist to salvage stereotactic radiosurgery (SRS) failures for brain metastases, including repeat SRS and hypofractionated SRS (HSRS). Our objective was to report outcomes specific to salvage HSRS for brain metastases that failed prior HSRS/SRS.

METHODS

Patients treated with HSRS to salvage local failures (LF) following initial HSRS/SRS, between July 2010 and April 2020, were retrospectively reviewed. The primary outcomes were the rates of LF, radiation necrosis (RN), and symptomatic radiation necrosis (SRN). Univariable (UVA) and multivariable (MVA) analyses using competing risk regression were performed to identify predictive factors for each endpoint.

RESULTS

120 Metastases in 91 patients were identified. The median clinical follow up was 13.4 months (range 1.1-111.1), and the median interval between SRS courses was 13.1 months (range 3.0-56.5). 115 metastases were salvaged with 20-35 Gy in 5 fractions and the remaining five with a total dose ranging from 20 to 24 Gy in 3-fractions. 67 targets (56%) were postoperative cavities. The median re-treatment target volume and biological effective dose (BED₁₀) was 9.5 cc and 37.5 Gy, respectively. The 6- and 12- month LF rates were 18.9% and 27.7%, for RN 13% and 15.6%, and for SRN were 6.1% and 7.0%, respectively. MVA identified larger re-irradiation volume (hazard ratio [HR] 1.02, p = 0.04) and shorter interval between radiosurgery courses (HR 0.93, p < 0.001) as predictors of LF. Treatment of an intact target was associated with a higher risk of RN (HR 2.29, p = 0.04).

CONCLUSION

Salvage HSRS results in high local control rates and toxicity rates that compare favorably to those single fraction SRS re-irradiation experiences reported in the literature.

Systematic review of the management of brain metastases from hormone receptor positive breast cancer

INTRODUCTION

Brain metastases are a common cause of morbidity and mortality in patients with breast cancer. Local central nervous system (CNS) directed therapies are usually the first line treatment for breast cancer brain metastases (BCBM), but those must be followed by systemic therapies to achieve long-term benefit. Systemic therapy for hormone receptor (HR⁺) breast cancer has evolved in the last 10 years, but their role when brain metastases occur is uncertain.

METHODS

We performed a systematic review of the literature focused on management of HR⁺ BCBM by searching Medline/PubMed, EBSCO, and Cochrane databases. The PRISMA guidelines were used for systematic review.

RESULTS

Out of 807 articles identified, 98 fulfilled the inclusion criteria in their relevance to the management of HR⁺ BCBM.

CONCLUSIONS

Similar to brain metastases from other neoplasms, local CNS directed therapies are the first line treatment for HR⁺ BCBM. Although the quality of evidence is low, after local therapies, our review supports the combination of targeted and endocrine therapies for both CNS and systemic management. Upon exhaustion of targeted/endocrine therapies, case series and retrospective reports suggest that certain chemotherapy agents are active against HR⁺ BCBM. Early phase clinical trials for HR⁺ BCBM are ongoing, but there is a need for prospective randomized trials to guide management and improve patients' outcome.

Efficacy of CDK 4/6 Inhibitors and Radiotherapy in Breast Cancer Patients with Brain Metastases

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) combined with endocrine therapy are the standard of care for HR-positive/HER2-negative advanced breast cancer patients. However, their role in the treatment of brain metastases is currently unclear. We retrospectively evaluate the results of patients (pts) with advanced breast cancer treated at our institution with CDK4/6i and radiotherapy to the brain. The primary endpoint was progression-free survival (PFS). Secondary endpoints were local control (LC) and severe toxicity. Among 371 pts treated with CDK4/6i, 24 pts (6.5%) received radiotherapy to the brain before (11 pts), during (6 pts), or after (7 pts) CDK4/6i treatment. Sixteen pts received ribociclib, six received palbociclib, and two received abemaciclib. Six- and twelve-month PFS was 76.5% (95% CI: 60.3-96.9) and 49.7% (95% CI: 31.7-77.9), respectively, whereas six- and twelve-month LC was 80.2% (95% CI: 58.7-100) and 68.8% (95% CI: 44.5-100), respectively. With a median follow-up of 9.5 months, no unexpected toxicity was observed. We conclude that treatment with both CDK4/6i and brain radiotherapy is feasible and should not increase the toxicity compared to brain radiotherapy or CDK4/6i alone. However, the small number of individuals treated concurrently limits the conclusions about the combination of both modalities, and the results from ongoing prospective clinical trials are eagerly awaited to understand both the toxicity profile and the clinical response fully.

The role of brain radiotherapy for EGFR- and ALK-positive non-small-cell lung cancer with brain metastases: a review

Non-small cell lung cancer (NSCLC) is frequently complicated by central nervous system (CNS) metastases affecting patients' life expectancy and quality. At the present clinical trials including neurosurgery, radiotherapy (RT) and systemic treatments alone or in combination have provided controversial results. CNS involvement is even more frequent in NSCLC patients with EGFR activating mutations or ALK rearrangement suggesting a role of target therapy in the upfront treatment in place of loco-regionals treatments (i.e. RT and/or surgery). So far clinical research has not explored the potential role of accurate brain imaging (i.e. MRI instead of the routine total-body contrast CT and/or PET/CT staging) to identify patients that could benefit of local therapies. Moreover, for patients who require concomitant RT there are no clear guidelines on the timing of intervention with respect to innovative precision medicine approaches with Tyrosine Kinase Inhibitors, ALK-inhibitors and/or immuno-oncological therapies. On this basis the present review describes the therapeutic strategies integrating medical and radiation oncology in patients with metastatic NSCLC (mNSCLC) adenocarcinoma with CNS involvement and EGFR activating mutations or ALK rearrangement.

Acquiring tissue for advanced lung cancer diagnosis and comprehensive biomarker testing: A National Lung Cancer Roundtable best-practice guide

Advances in biomarker-driven therapies for patients with nonsmall cell lung cancer (NSCLC) both provide opportunities to improve the treatment (and thus outcomes) for patients and pose new challenges for equitable care delivery. Over the last decade, the continuing development of new biomarker-driven therapies and evolving indications for their use have intensified the importance of interdisciplinary communication and coordination for patients with or suspected to have lung cancer. Multidisciplinary teams are challenged with completing comprehensive and timely biomarker testing and navigating the constantly evolving evidence base for a complex and time-sensitive disease. This guide provides context for the current state of comprehensive biomarker testing for NSCLC, reviews how biomarker testing integrates within the diagnostic continuum for patients, and illustrates best practices and common pitfalls that influence the success and timeliness of biomarker testing using a series of case scenarios.

Clinical outcome of patients with isolated central nervous system progression on first-line pertuzumab and trastuzumab treatment for HER2-positive metastatic breast cancer in a real-life cohort

BACKGROUND

More than 10% of HER2-positive metastatic breast cancer (mBC) will develop Central Nervous System (CNS) metastases as first and isolated site of relapse on trastuzumab and pertuzumab first-line therapy. However, few clinical data are available to guide the best strategy in this setting.

METHODS

Patients experiencing isolated CNS progression on trastuzumab and pertuzumab first-line therapy were retrospectively identified from the French Epidemiological Strategy and Medical Economics (ESME) real-life database between 2008 and 2016.

RESULTS

Among 995 patients treated with first-line trastuzumab and pertuzumab for HER2-positive mBC, 132 patients (13%) experienced isolated CNS progression with a median time of 12 months after mBC diagnosis. Twelves patients did not receive any treatment and were excluded from the analysis. Among the 120 patients considered, 76 (63%) received CNS-directed local therapy, 73 (60%) continued trastuzumab and pertuzumab, whereas 47 (39%) started another systemic treatment. After a median follow-up of 21 months, there was no difference in progression-free survival for patient who continued trastuzumab-pertuzumab or switched to another systemic treatment. In multivariate analysis, trastuzumab-pertuzumab continuation was associated with longer OS (HR 0,28 IC 95%: 0,14-0,54 p < 0,001). mOS was not reached (95% 37.6-NE) and was 23.2 months (95% CI 15.5-53.6) in patients who continued trastuzumab and pertuzumab therapy and in patients who switched for another systemic therapy, respectively.

CONCLUSION

In this real-life cohort, trastuzumab-pertuzumab continuation after local treatment for isolated CNS progression did not negatively impact PFS and OS. Prospective trials and assessment of new strategies are warranted in this specific situation.

Are the Choosing Wisely Canada Cancer recommendations relevant and up to date with the current evidence?

INTRODUCTION

The Choosing Wisely (CW) Canada campaign was launched in 2012 to identify low-value, unnecessary and/or harmful services that are frequently used. The CW Canada Cancer list was developed in 2014 by a task force convened by the Canadian Partnership Against Cancer. The list outlines ten harmful or low-value practices that oncologists should avoid. We conducted a study of oncologists to understand the familiarity with the current recommendations and whether these continue to be relevant and up to date.

METHODS

An electronic survey was developed by the members of the CW Oncology Working Group and distributed to practicing oncologists. The survey consisted of questions on 1) the familiarity of the existing CW Canada Cancer list 2) the relevance of the current list to current evidence and 3) any recommendation(s) that could be added or removed from the existing list. Descriptive statistics were used to analyze responses and narrative analysis was used to identify themes in open-ended questions.

RESULTS

Between January 14 and May 3, 2022, 151 survey responses were received (overall response rate of 20 %) from 68 medical oncologists (45 % of study cohort, response rate 32 %), 54 radiation oncologists (36 % of study cohort, response rate 14 %) and 29 surgical oncologists (19 % of study cohort, response rate 18 %). Seventy-nine percent (120/151) of respondents were familiar with the current list and 65 % (78/119) said they implemented the recommendations "always" or "most of the time". Eight recommendations had > 80 % agreement that they were relevant and up to date with current evidence. There was interest in adding a new recommendation to avoid whole brain radiation and consider stereotactic radiosurgery (SRS) in patients with ≤ 4 brain metastases.

CONCLUSIONS

There is excellent familiarity with the CW Canada Cancer list amongst the survey respondents and most recommendations continue to be relevant and up to date with current evidence. There is an opportunity to educate physicians about the intent of the campaign and to add a new recommendation on the use of SRS for patients with a limited number of brain metastases. There is also an opportunity to identify barriers at the patient, provider and institution level that are hindering adoption of the CW Canada Cancer list POLICY SUMMARY: This survey will impact implementation and publication of an updated CW Canada Cancer list.

Stereotactic Radiosurgery for Intraventricular Metastases: A Multicenter Study

BACKGROUND

Intraventricular metastases (IVMs) are uncommon, and their optimal management remains debatable.

OBJECTIVE

To define the safety and efficacy of stereotactic radiosurgery (SRS) in the treatment of IVMs.

METHODS

This retrospective, multicenter study included patients managed with SRS for IVMs. SRS-induced adverse events, local tumor or intracranial progression, and the frequency of new-onset hydrocephalus or leptomeningeal spread were documented. Analyses of variables related to patient neuroimaging or clinical outcomes were also performed.

RESULTS

The cohort included 160 patients from 11 centers who underwent SRS for treatment of 1045 intracranial metastases, of which 196 were IVMs. The median survival from SRS was 10 months. Of the 154 patients and 190 IVMs with imaging follow-up, 94 patients (61%) experienced distant intracranial disease progression and 16 IVMs (8.4%) progressed locally. The 12- and 24-month local IVM control rates were 91.4% and 86.1%, respectively. Sixteen (10%) and 27 (17.5%) patients developed hydrocephalus and leptomeningeal dissemination post-SRS, respectively. Adverse radiation effects were documented in 24 patients (15%). Eleven patients (6.9%) died because of intracranial disease progression.

CONCLUSION

SRS is an effective treatment option for IVMs, with a local IVM control rate comparable with SRS for parenchymal brain metastases. Leptomeningeal spread and hydrocephalus in patients with IVM occur in a minority of patients, but these patients warrant careful follow-up to detect these changes.

Tumor Habitat Analysis Using Longitudinal Physiological MRI to Predict Tumor Recurrence After Stereotactic Radiosurgery for Brain Metastasis

OBJECTIVE

It is difficult to predict the treatment response of tissue after stereotactic radiosurgery (SRS) because radiation necrosis (RN) and tumor recurrence can coexist. Our study aimed to predict tumor recurrence, including the recurrence site, after SRS of brain metastasis by performing a longitudinal tumor habitat analysis.

MATERIALS AND METHODS

Two consecutive multiparametric MRI examinations were performed for 83 adults (mean age, 59.0 years; range, 27-82 years; 44 male and 39 female) with 103 SRS-treated brain metastases. Tumor habitats based on contrast-enhanced T1- and T2-weighted images (structural habitats) and those based on the apparent diffusion coefficient (ADC) and cerebral blood volume (CBV) images (physiological habitats) were defined using k-means voxel-wise clustering. The reference standard was based on the pathology or Response Assessment in Neuro-Oncologycriteria for brain metastases (RANO-BM). The association between parameters of single-time or longitudinal tumor habitat and the time to recurrence and the site of recurrence were evaluated using the Cox proportional hazards regression analysis and Dice similarity coefficient, respectively.

RESULTS

The mean interval between the two MRI examinations was 99 days. The longitudinal analysis showed that an increase in the hypovascular cellular habitat (low ADC and low CBV) was associated with the risk of recurrence (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.46-4.91; P = 0.001). During the single-time analysis, a solid low-enhancing habitat (low T2 and low contrast-enhanced T1 signal) was associated with the risk of recurrence (HR, 1.54; 95% CI, 1.01-2.35; P = 0.045). A hypovascular cellular habitat was indicative of the future recurrence site (Dice similarity coefficient = 0.423).

CONCLUSION

After SRS of brain metastases, an increased hypovascular cellular habitat observed using a longitudinal MRI analysis was associated with the risk of recurrence (i.e., treatment resistance) and was indicative of recurrence site. A tumor habitat analysis may help guide future treatments for patients with brain metastases.

Frequency of seizures in patients with metastatic brain tumors

INTRODUCTION

We sought to determine the influence of primary tumor histology and metastatic tumor location on the frequency of seizures among patients with brain metastases. A secondary aim was to determine if surgery reduced the occurrence and frequency of seizures.

METHODS

We retrospectively reviewed patients with cerebral metastasis at a single institution from 2006 to 2016.

RESULTS

Among 1949 patients identified as having had cerebral metastasis, 168 (8.6%) had documentation of one or more seizures. The incidence of seizures was highest among patients with metastases from melanoma (19.8%), followed by those with colon cancer (9.7%), renal cell carcinoma (RCC; 8.3%), and lung cancer (7.0%). Among 1581 patients with melanoma, colon cancer, RCC, non-small cell lung cancer, or breast cancer, having metastases in the frontal lobe seemed to confer the greatest risk of seizures (n = 100), followed by foci in the temporal lobe (n = 20) and elsewhere (n = 16).

CONCLUSION

Patients with cerebral metastasis are at increased risk for seizures. Seizure rates seem to be higher for certain primary tumors, such as melanoma, colon cancer, and RCC, and for lesions located in the frontal lobe.

Neurologic complications of breast cancer

Breast cancer is a heterogeneous disease with unique neurologic complications that can arise from central nervous system (CNS) involvement or secondary to treatments themselves. As progress is made, with more targeted therapies and combinations available, particularly in the realm of human epidermal growth factor receptor 2 (HER2)-positive disease, the role of these new agents in patients with CNS disease is gradually evolving, although intracranial efficacy itself is lagging. At the same time, both systemic and local standard therapies pose clinical challenges regarding neurologic complications, such as peripheral neuropathy and cognitive changes. The development of new agents, such as immunotherapy, and new strategies, such as incorporating systemic therapies into local therapy, unveil new presentations of neurological complications.

Treatments for brain metastases from EGFR/ALK-negative/unselected NSCLC: A network meta-analysis

More clinical evidence is needed regarding the relative priority of treatments for brain metastases (BMs) from EGFR/ALK-negative/unselected non-small cell lung cancer (NSCLC). PubMed, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials.gov databases were searched. Overall survival (OS), central nervous system progression-free survival (CNS-PFS), and objective response rate (ORR) were selected for Bayesian network meta-analyses. We included 25 eligible randomized control trials (RCTs) involving 3,054 patients, investigating nine kinds of treatments for newly diagnosed BMs and seven kinds of treatments for previously treated BMs. For newly diagnosed BMs, adding chemotherapy, EGFR-TKIs, and other innovative systemic agents (temozolomide, nitroglycerin, endostar, enzastaurin, and veliparib) to radiotherapy did not significantly prolong OS than radiotherapy alone; whereas radiotherapy + nitroglycerin showed significantly better CNS-PFS and ORR. Surgery could significantly prolong OS (hazard ratios [HR]: 0.52, 95% credible intervals: 0.41-0.67) and CNS-PFS (HR: 0.32, 95% confidence interval: 0.18-0.59) compared with radiotherapy alone. For previously treated BMs, pembrolizumab + chemotherapy, nivolumab + ipilimumab, and cemiplimab significantly prolonged OS than chemotherapy alone. Pembrolizumab + chemotherapy also showed better CNS-PFS and ORR than chemotherapy. In summary, immune checkpoint inhibitor (ICI)-based therapies, especially ICI-combined therapies, showed promising efficacies for previously treated BMs from EGFR/ALK-negative/unselected NSCLC. The value of surgery should also be emphasized. The result should be further confirmed by RCTs.

Survival Benefits of Radiotherapy and Surgery in Lung Cancer Brain Metastases with Poor Prognosis Factors

BACKGROUND

Radiotherapy and surgery are the standard local treatments for lung cancer brain metastases (BMs). However, limited studies focused on the effects of radiotherapy and surgery in lung cancer BMs with poor prognosis factors.

METHODS

We retrospectively analyzed 714 patients with lung cancer BMs. Analyses of overall survival (OS) and risk factors for OS were assessed by the log-rank test and Cox proportional hazard model.

RESULTS

Age ≥ 65 years, a Karnofsky Performance Scale (KPS) score ≤ 70, anaplastic large-cell lymphoma kinase (ALK)/epidermal growth factor receptor (EGFR) wild type, and extracranial metastases were related to poor prognosis. Patients were stratified according to these poor prognosis factors. In patients with the ALK/EGFR wild type, whole brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and surgery improved the OS of patients. WBRT and SRS were the independent protective factors for OS. In patients with extracranial metastases, patients who received WBRT plus SRS or WBRT alone had longer OS than those who did not receive radiotherapy. WBRT plus SRS and WBRT were the independent protective factors for OS.

CONCLUSIONS

Radiotherapy and surgery are associated with improved survival for lung cancer BMs with the ALK/EGFR wild type. Radiotherapy is associated with improved survival in lung cancer BMs with extracranial metastases.

Upfront Advanced Radiotherapy and New Drugs for NSCLC Patients with Synchronous Brain Metastases: Is the Juice Worth the Squeeze? A Real-World Analysis from Lombardy, Italy

AIM

Healthcare administrative databases represent a valuable source for real-life data analysis. The primary aim of this study is to compare effectiveness and cost profile in non-small-cell lung cancer (NSCLC) patients harboring synchronous brain metastases (BMs) who received non-chemo first-line systemic therapy with or without advanced radiotherapy (aRT).

METHODS

Diagnostic ICD-9-CM codes were used for identifying all patients with a new diagnosis of lung cancer between 2012 and 2019. Among these, patients who had started a first-line systemic treatment with either TKIs or pembrolizumab, alone or in combination with intensity-modulated or stereotactic RT, were selected. Clinical outcomes investigated included overall survival (OS), progression-free survival (PFS), and time-to-treatment failure (TTF). The cost outcome was defined as the average per capita cumulative healthcare direct costs of the treatment, including all inpatient and outpatient costs.

RESULTS

The final cohort included 177 patients, of whom 58 were treated with systemic treatment plus aRT (STRT) and 119 with systemic treatment alone. The addition of aRT to systemic treatment was associated with a significantly better OS (p = 0.020) and PFS (p = 0.041) than systemic therapy alone. The ICER (incremental cost-effectiveness ratio) value indicated an average cost of €3792 for each month of survival after STRT treatment and confirmed clinical effectiveness but higher healthcare costs.

CONCLUSIONS

This real-world study suggests that upfront aRT for NCLSC patients with synchronous BMs represents a valid treatment strategy, boosting the efficacy of novel and emerging drug classes with sustainable costs for the health service.

TRANSLATIONAL RELEVANCE

The present real-world study reports that the use of upfront advanced radiotherapyaRT and new-generation systemic agents, such as TKIs and pembrolizumab, may have higher oncological control and an improved cost-effectiveness profile than the use of new-generation systemic agents alone in NCLSC patients with synchronous brain metastases. Acquired evidence can also be used to inform policymakers that adding advanced radiotherapy results is a sustainable cost for the health service. Since approximately 50% of patients do not meet RCT inclusion criteria, a significant proportion of them is receiving treatment that is not evidence-informed; therefore, these results warrant further studies to identify the best radiotherapy timing and possible dose escalation approaches to improving treatment efficacy in patient subgroups not typically represented in randomized controlled trials.

Efficacy, Safety, and Health-Related Quality of Life With Camrelizumab Plus Pemetrexed and Carboplatin as First-Line Treatment for Advanced Nonsquamous NSCLC With Brain Metastases (CAP-BRAIN): A Multicenter, Open-Label, Single-Arm, Phase 2 Study

INTRODUCTION

Systemic treatment options for NSCLC with brain metastases (BMs) are scarce. We evaluated the activity and safety of camrelizumab plus chemotherapy as first-line therapy in patients with advanced nonsquamous NSCLC with BMs.

METHODS

This was a multicenter, single-arm, phase 2 trial (NCT04211090) conducted at seven hospitals in China. Eligible patients had treatment-naive metastatic nonsquamous NSCLC and BMs that were asymptomatic or symptoms controlled with dehydration therapy and no previous systemic treatment or local therapy for the target brain lesion. Patients received camrelizumab (200 mg) plus pemetrexed (500 mg/m²) and carboplatin (area under the curve 5) intravenously on day 1 of each 21-day cycle for four cycles, followed by maintenance with camrelizumab (200 mg) and pemetrexed (500 mg/m²) every 21 days until disease progression, unacceptable toxicity, or death. The primary end point was confirmed intracranial objective response rate according to modified Response Evaluation Criteria in Solid Tumors version 1.1, which was primarily analyzed in the efficacy analysis set (EAS).

RESULTS

A total of 45 patients were enrolled and treated (full analysis set), with 40 patients having at least one post-baseline tumor assessment (EAS). As of August 30, 2022, median follow-up duration was 12.5 months (95% confidence interval [CI]: 9.2-17.3). The confirmed intracranial objective response rate was 52.5% (95% CI: 36.1-68.5) in EAS and 46.7% (95% CI: 31.7-62.1) in full analysis set. The extracranial objective response rate was 47.5% (95% CI: 31.5-63.9) and 42.2% (95% CI: 27.7-57.8), respectively. Median intracranial progression-free survival was 7.6 months (95% CI: 4.6-not reached [NR]), median overall progression-free survival was 7.4 months (95% CI: 4.4-NR), and median overall survival was 21.0 months (95% CI: 15.9-NR). The most common treatment-related adverse events of grade 3 or higher were neutrophil count decrease (six [13.3%]) and anemia (four [8.9%]). One treatment-related death occurred owing to immune-related pneumonia. Linear mixed-effects model displayed that a positive trend for improvement in cognitive function and quality of life was observed based on Montreal Cognitive Assessment and Functional Assessment of Cancer Therapy-Lung scores (p = 0.025, p < 0.001).

CONCLUSIONS

Camrelizumab plus pemetrexed and carboplatin was found to have an activity with manageable toxicity and to improve cognitive function and quality of life for patients with nonsquamous NSCLC with BMs in the first-line setting.

Proteomic analysis of brain metastatic lung adenocarcinoma reveals intertumoral heterogeneity and specific alterations associated with the timing of brain metastases

BACKGROUND

Brain metastases are associated with considerable negative effects on patients' outcome in lung adenocarcinoma (LADC). Here, we investigated the proteomic landscape of primary LADCs and their corresponding brain metastases.

MATERIALS AND METHODS

Proteomic profiling was conducted on 20 surgically resected primary and brain metastatic LADC samples via label-free shotgun proteomics. After sample processing, peptides were analyzed using an Ultimate 3000 pump coupled to a QExactive HF-X mass spectrometer. Raw data were searched using PD 2.4. Further data analyses were carried out using Perseus, RStudio and GraphPad Prism. Proteomic data were correlated with clinical and histopathological parameters and the timing of brain metastases. Mass spectrometry-based proteomic data are available via ProteomeXchange with identifier PXD027259.

RESULTS

Out of the 6821 proteins identified and quantified, 1496 proteins were differentially expressed between primary LADCs and corresponding brain metastases. Pathways associated with the immune system, cell-cell/matrix interactions and migration were predominantly activated in the primary tumors, whereas pathways related to metabolism, translation or vesicle formation were overrepresented in the metastatic tumors. When comparing fast- versus slow-progressing patients, we found 454 and 298 differentially expressed proteins in the primary tumors and brain metastases, respectively. Metabolic reprogramming and ribosomal activity were prominently up-regulated in the fast-progressing patients (versus slow-progressing individuals), whereas expression of cell-cell interaction- and immune system-related pathways was reduced in these patients and in those with multiple brain metastases.

CONCLUSIONS

This is the first comprehensive proteomic analysis of paired primary tumors and brain metastases of LADC patients. Our data suggest a malfunction of cellular attachment and an increase in ribosomal activity in LADC tissue, promoting brain metastasis. The current study provides insights into the biology of LADC brain metastases and, moreover, might contribute to the development of personalized follow-up strategies in LADC.

The role of immune checkpoint inhibitors in patients with intracranial metastatic disease

Intracranial metastatic disease (IMD) complicates the course of nearly 2-4% of patients with systemic cancer. The prevalence of IMD has been increasing over the past few decades. Historically, definitive treatment for brain metastases (BM) has been limited to radiation therapy or surgical resection. Chemotherapies have not typically proven valuable in the treatment of IMD, with the exception of highly chemotherapy-sensitive lesions. Recent data have supported a role for systemic targeted therapies and immune checkpoint inhibitors (ICIs) in the treatment of select patients with IMD. There remains, however, a clear clinical need for further investigation to delineate the role of ICIs in patients with BM. In this review, we outline and describe recent and current efforts to identify the efficacy of ICI therapy in patients with IMD.

Tucatinib vs Placebo, Both in Combination With Trastuzumab and Capecitabine, for Previously Treated ERBB2 (HER2)-Positive Metastatic Breast Cancer in Patients With Brain Metastases: Updated Exploratory Analysis of the HER2CLIMB Randomized Clinical Trial

Importance

It is estimated that up to 50% of patients with ERBB2 (HER2)-positive metastatic breast cancer (MBC) will develop brain metastases (BMs), which is associated with poor prognosis. Previous reports of the HER2CLIMB trial have demonstrated that tucatinib in combination with trastuzumab and capecitabine provides survival and intracranial benefits for patients with ERBB2-positive MBC and BMs.

Objective

To describe overall survival (OS) and intracranial outcomes from tucatinib in combination with trastuzumab and capecitabine in patients with ERBB2-positive MBC and BMs with an additional 15.6 months of follow-up.

Design, Setting, and Participants

HER2CLIMB is an international, multicenter, randomized, double-blind, placebo-controlled clinical trial evaluating tucatinib in combination with trastuzumab and capecitabine. The 612 patients, including those with active or stable BMs, had ERBB2-positive MBC previously treated with trastuzumab, pertuzumab, and trastuzumab emtansine. The study was conducted from February 23, 2016, to May 3, 2019. Data from February 23, 2016, to February 8, 2021, were analyzed.

Interventions

Patients were randomized 2:1 to receive tucatinib (300 mg orally twice daily) or placebo (orally twice daily), both in combination with trastuzumab (6 mg/kg intravenously or subcutaneously every 3 weeks with an initial loading dose of 8 mg/kg) and capecitabine (1000 mg/m2 orally twice daily on days 1-14 of each 3-week cycle).

Main Outcomes and Measures

Evaluations in this exploratory subgroup analysis included OS and intracranial progression-free survival (CNS-PFS) in patients with BMs, confirmed intracranial objective response rate (ORR-IC) and duration of intracranial response (DOR-IC) in patients with measurable intracranial disease at baseline, and new brain lesion-free survival in all patients. Only OS was prespecified before the primary database lock.

Results

At baseline, 291 of 612 patients (47.5%) had BMs. Median age was 52 years (range, 22-75 years), and 289 (99.3%) were women. At median follow-up of 29.6 months (range, 0.1-52.9 months), median OS was 9.1 months longer in the tucatinib-combination group (21.6 months; 95% CI, 18.1-28.5) vs the placebo-combination group (12.5 months; 95% CI, 11.2-16.9). The tucatinib-combination group showed greater clinical benefit in CNS-PFS and ORR-IC compared with the placebo-combination group. The DOR-IC was 8.6 months (95% CI, 5.5-10.3 months) in the tucatinib-combination group and 3.0 months (95% CI, 3.0-10.3 months) in the placebo-combination group. Risk of developing new brain lesions as the site of first progression or death was reduced by 45.1% in the tucatinib-combination group vs the placebo-combination group (hazard ratio, 0.55 [95% CI, 0.36-0.85]).

Conclusions and Relevance

This subgroup analysis found that tucatinib in combination with trastuzumab and capecitabine improved OS while reducing the risk of developing new brain lesions, further supporting the importance of this treatment option for patients with ERBB2-positive MBC, including those with BMs.

Trial Registration

ClinicalTrials.gov Identifier: NCT02614794.

Stereotactic radiosurgery versus whole-brain radiotherapy after resection of solitary brain metastasis: A systematic review and meta-analysis

Objective

The standard of care in patients with solitary brain metastasis involves surgical resection and postoperative whole-brain radiotherapy (WBRT). However, WBRT is associated with adverse effects, mainly neurocognitive deterioration. Stereotactic radiosurgery (SRS) is a more targeted form of radiation therapy that could be as effective as WBRT without the detrimental neurocognitive decline.

Methods

We performed the first systematic review and meta-analysis comparing postoperative SRS versus postoperative WBRT in patients with one resected brain metastasis. PubMed, Scopus, and Cochrane library were systematically searched for studies comparing the efficacy of the two radiation modalities in terms of local and distant brain control, leptomeningeal disease control, and overall survival. Additionally, we extracted patients' neurocognitive function and quality of life after each postoperative radiation form.

Results

Four studies with 248 patients (128: WBRT, 120: SRS) were included in our analysis. There was no difference between SRS and WBRT in the risk of local recurrence (RR = 0.92, CI = 0.51-1.66, p = 0.78, I2 = 0%) and leptomeningeal disease (RR = 1.21, CI = 0.49-2.98, p = 0.67, I2 = 18%), neither in the patients' overall survival (HR = 1.06, CI = 0.61-1.85, p = 0.83, I2 = 63%). Nevertheless, SRS appeared to increase the risk of distant brain failure (RR = 2.03, CI = 0.94-4.40, p = 0.07, I2 = 61%). Neurocognitive function and quality of life in the SRS group were equal or superior to the WBRT group.

Conclusions

Although SRS may increase the risk of distant brain failure, it appears to be as effective as WBRT in terms of local control, risk of leptomeningeal disease, and overall survival while sparing the patients of the detrimental, WBRT-associated cognitive deterioration.

Prognostic impact of extracranial disease control in HER2+ breast cancer-related brain metastases

BACKGROUND

Brain metastases (BM) are common among HER2+ breast cancer (BC) and prognostic stratification is crucial for optimal management. BC-GPA score and subsequent refinements (modified-GPA, updated-GPA) recapitulate prognostic factors. Since none of these indexes includes extracranial disease control, we evaluated its prognostic value in HER2+ BCBM.

METHODS

Patients diagnosed with HER2+ BCBM at Istituto Oncologico Veneto-Padova (2002-2021) and Montpellier Cancer Institute (2001-2015) were included as exploratory and validation cohorts, respectively. Extracranial disease control at BM diagnosis (no disease/stable disease/response vs. progressive disease) was evaluated.

RESULTS

In the exploratory cohort of 113 patients (median OS 12.2 months), extracranial control (n = 65, 57.5%) was significantly associated with better OS at univariate (median OS 17.7 vs. 8.7 months, p = 0.005) and multivariate analysis after adjustment for BC-GPA (HR 0.61, 95% CI 0.39-0.94), modified-GPA (HR 0.64, 95% CI 0.42-0.98) and updated-GPA (HR 0.63, 95% CI 0.41-0.98). The prognostic impact of extracranial disease control (n = 66, 56.4%) was then confirmed in the validation cohort (n = 117) at univariate (median OS 20.2 vs. 9.1 months, p < 0.001) and multivariate analysis adjusting for BC-GPA (HR 0.41, 95% CI 0.27-0.61), modified-GPA (HR 0.44, 95% CI 0.29-0.67) and updated-GPA (HR 0.42, 95% CI 0.28-0.63).

CONCLUSIONS

Extracranial disease control provides independent prognostic information in HER2+ BCBM beyond commonly used prognostic scores.

Advances in the Management of Central Nervous System Metastases in Non-Small Cell Lung Cancer

Central nervous system (CNS) metastases are common among patients with non-small cell lung cancer (NSCLC). While the presence of brain metastases has historically portended poor prognosis, recent advances in local and systemic therapies have greatly improved outcomes for NSCLC patients with CNS involvement. Stereotactic radiology surgery (SRS) has emerged as an effective radiotherapy technique with fewer toxicities compared to whole brain radiotherapy (WBRT). Furthermore, multi-generation tyrosine kinase inhibitors (TKIs) with CNS overall response rates (ORR) of up to 70-80% are now an accepted first-line approach for a subset of advanced NSCLC patients with targetable molecular alterations. In addition, while the CNS was once considered an immunologic sanctuary site, growing evidence shows that immune checkpoint inhibitors (ICIs) can induce durable responses in brain metastases as well. Ongoing efforts to optimize CNS metastases management are necessary to refine multimodal treatment approaches and develop new therapeutics with better CNS penetrance.

Brain Metastases from Biliary Tract Cancer: Case Series and Clinicogenomic Analysis

BACKGROUND

Limited data from small series have suggested that brain metastases from biliary tract cancers (BrM-BTC) affect ≤2% of patients with BTC. We sought to review our experience with patients with BrM-BTC and to identify associations of tumor-related molecular alterations with outcomes.

MATERIALS AND METHODS

A retrospective review of patients with BTC seen at a tertiary referral center from 2005 to 2021 was performed; patients with BrM-BTC were identified, and clinical and molecular data were collected.

RESULTS

Twenty-one of 823 patients with BTC (2.6%) developed BrM. For patients with BrM-BTC, median follow-up time was 27.9 months after primary BTC diagnosis and 3.1 months after BrM diagnosis. Median time from primary diagnosis to diagnosis of BrM was 14.4 [range, 1.1-66.0] months. Median overall survival (OS) from primary diagnosis was 31.5 [2.9-99.8] months and median OS from BrM diagnosis was 4.2 [0.2-33.8] months. Patients who underwent BrM-directed therapy trended toward longer OS following BrM diagnosis than patients receiving supportive care only (median 6.5 vs 0.8 months, P = .060). The BrM-BTC cohort was enriched for BRAF (30%), PIK3CA (25%), and GNAS (20%) mutations. patients with BrM-BTC with BRAF mutations trended toward longer OS following BrM diagnosis (median 13.1 vs 4.2 months, P = .131).

CONCLUSION

This is the largest series of patients with BrM-BTC to date and provides molecular characterization of this rare subgroup of patients with BTC. Patients with BrM-BTC may be more likely to have BRAF mutations. With advances in targeted therapy for patients with BTC with actionable mutations, continued examination of shifting patterns of failure, with emphasis on BrM, is warranted.

Dosimetric Impact of Lesion Number, Size, and Volume on Mean Brain Dose with Stereotactic Radiosurgery for Multiple Brain Metastases

We evaluated the effect of lesion number and volume for brain metastasis treated with SRS using GammaKnife^® ICON™ (GK) and CyberKnife^® M6™ (CK). Four sets of lesion sizes (<5 mm, 5-10 mm, >10-15 mm, and >15 mm) were contoured and prescribed a dose of 20 Gy/1 fraction. The number of lesions was increased until a threshold mean brain dose of 8 Gy was reached; then individually optimized to achieve maximum conformity. Across GK plans, mean brain dose was linearly proportional to the number of lesions and total GTV for all sizes. The numbers of lesions needed to reach this threshold for GK were 177, 57, 29, and 10 for each size group, respectively; corresponding total GTVs were 3.62 cc, 20.37 cc, 30.25 cc, and 57.96 cc, respectively. For CK, the threshold numbers of lesions were 135, 35, 18, and 8, with corresponding total GTVs of 2.32 cc, 12.09 cc, 18.24 cc, and 41.52 cc respectively. Mean brain dose increased linearly with number of lesions and total GTV while V8 Gy, V10 Gy, and V12 Gy showed quadratic correlations to the number of lesions and total GTV. Modern dedicated intracranial SRS systems allow for treatment of numerous brain metastases especially for ≤10 mm; clinical evidence to support this practice is critical to expansion in the clinic.

Advances in the Molecular Landscape of Lung Cancer Brain Metastasis

Lung cancer is one of the most frequent tumors that metastasize to the brain. Brain metastasis (BM) is common in advanced cases, being the major cause of patient morbidity and mortality. BMs are thought to arise via the seeding of circulating tumor cells into the brain microvasculature. In brain tissue, the interaction with immune cells promotes a microenvironment favorable to the growth of cancer cells. Despite multimodal treatments and advances in systemic therapies, lung cancer patients still have poor prognoses. Therefore, there is an urgent need to identify the molecular drivers of BM and clinically applicable biomarkers in order to improve disease outcomes and patient survival. The goal of this review is to summarize the current state of knowledge on the mechanisms of the metastatic spread of lung cancer to the brain and how the metastatic spread is influenced by the brain microenvironment, and to elucidate the molecular determinants of brain metastasis regarding the role of genomic and transcriptomic changes, including coding and non-coding RNAs. We also present an overview of the current therapeutics and novel treatment strategies for patients diagnosed with BM from NSCLC.

A phase II single-arm trial of memantine for prevention of cognitive decline during chemotherapy in patients with early breast cancer: Feasibility, tolerability, acceptability, and preliminary effects

BACKGROUND

Cognitive difficulties have been described after chemotherapy for breast cancer, but there is no standard of care to improve cognitive outcomes in these patients. This trial examined the feasibility, tolerability, acceptability, and preliminary effects of memantine to prevent cognitive decline during chemotherapy for breast cancer.

METHODS

Patients with stage I-III breast cancer, scheduled for neo/adjuvant chemotherapy, completed a cognitive battery prior to and 4 weeks after completing chemotherapy. Memantine (10 mg BID) was administered concurrent with chemotherapy. Our primary cognitive outcome was visual working memory assessed by the Delayed Matching to Sample test. We used the Brief Medication Questionnaire to assess acceptability.

RESULTS

Of 126 patients approached, 56 (44%) enrolled. Forty-five (80%) received ≥1 dose of memantine and completed pre-post assessments. Seventy-six percent reported taking ≥90% of scheduled doses. Participants were mean age of 56, 77% White, and 57% had stage I disease. Sixty-four percent had stable or improved Delayed Matching to Sample test scores. Stable or improved cognition was observed in 87%-91% across objective cognitive domain composite measures. Sixty-six percent self-reported stable or improved cognitive symptoms. There were seven greater than or equal to grade 3 adverse events; two were possibly related to memantine. Only 5% reported that taking memantine was a disruption to their lives.

CONCLUSIONS

Memantine was well-tolerated and consistently taken by a large majority of patients receiving breast cancer chemotherapy. The majority demonstrated stable or improved cognition from pre- to post-assessment. Randomized trials are needed to determine memantine's efficacy to ameliorate cognitive loss.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04033419.

IMPACT the Brain: A Team-Based Approach to Management of Metastatic Breast Cancer With CNS Metastases

PURPOSE

CNS metastases are associated with decreased survival and quality of life for patients with metastatic breast cancer (MBC). Team-based care can optimize outcomes. IMPACT the Brain is a care coordination program that aims to improve access to team-based care for patients with MBC and CNS metastases.

MATERIALS AND METHODS

Patients with MBC and CNS metastases were eligible for enrollment in this care coordination program. A team of specialists supported a dedicated program coordinator who provided navigation, education, specialty referral, and clinical trial screening. A unique intake form developed for the program created personalized, coordinated, and expedited specialty referrals. Patient-reported outcomes and caregiver burden assessments were collected on a voluntary basis throughout enrollment. Data were analyzed using descriptive statistics.

RESULTS

Sixty patients were referred, and 53 were enrolled (88%). The median time to program enrollment was 1 day (range, 0-11) and to first visit was 5 days (range, 0-25). On the basis of the program intake form, 47 referrals were made across six specialties, most commonly physical medicine and rehabilitation (n = 10), radiation oncology (n = 10), and neuropsychology (n = 10). Nineteen patients (36%) consented to enroll in clinical trials.

CONCLUSION

A tailored team-based care coordination program for patients with MBC and CNS metastases is feasible. Use of a unique intake screening form by a dedicated program coordinator resulted in faster time to first patient visit, enabled access to subspecialist care, and supported enrollment in clinical trials. Future research should focus on intervention development using PRO data collected in this care coordination program.

Efficacy and safety of combined immunotherapy and stereotactic radiosurgery in NSCLCBM patients and a novel prognostic nomogram: A real-world study

Objective

To explore the effectiveness of combined immunotherapy (IT) and stereotactic radiosurgery (SRS) and address the gap between evidence-based clinical practice and academic knowledge of optimal timing of IT relative to SRS. In addition, to meet the unmet need for an up-to-date prognostic assessment model in the era of IT.

Methods

The data of 86 non-small cell lung cancer brain metastasis (NSCLCBM) patients treated with SRS to 268 brain metastases (BMs) were retrospectively extracted from our hospital database. The Kaplan-Meier analysis was employed for overall survival (OS) and a log-rank test for comparison between groups. Cox proportional hazards regression models were used to identify the significant prognostic factors. The prognostic nomogram was established utilizing the rms package of R software.

Results

IT was found to be associated with improved OS (from BM diagnosis: HR 0.363, 95% CI 0.199 - 0.661, P < 0.001; from SRS: HR 0.472, 95% CI 0.260 - 0.857, P = 0.014). Individuals who received IT in combination with SRS had better OS than those who didn't (from the day of BM diagnosis: 16.8 vs. 8.4 months, P = 0.006; from the day of SRS: 12 vs. 7 months, P = 0.037). Peri-SRS timing of IT administration was a significant prognostic factor for OS (from BM diagnosis: HR 0.132, 95% CI 0.034 - 0.517, P = 0.004; from SRS: HR 0.14, 95% CI 0.044 - 0.450, P = 0.001). Initiating IT after SRS led to superior OS than concurrent or before (from BM diagnosis: 26.5 vs. 14.1 vs. 7.1 months; from SRS: 21.4 vs. 9.9 vs. 4.1 months, respectively). Additionally, we build a nomogram incorporating IT, cumulative intracranial tumor volume (CITV), and recursive partitioning analysis (RPA), demonstrating a remarkable prognosis prediction performance for SRS-treated NSCLCBM patients.

Conclusion

Peri-SRS IT is a promising approach in treating NSCLCBM, as improved OS was observed without significantly increasing adverse events. Receipt of IT post-SRS was associated with superior OS than those who received IT concurrently or before. Incorporating IT and CITV into the RPA index could augment its prognosis assessment value for SRS-treated NSCLCBM patients, predominantly in the wild-type.

Osimertinib for EGFR-Mutant Non-Small-Cell Lung Cancer Central Nervous System Metastases: Current Evidence and Future Perspectives on Therapeutic Strategies

Central nervous system (CNS) metastases are common in non-small-cell lung cancer (NSCLC) and associated with poor prognosis and high disease burden. Effective options are needed to treat CNS metastases, and delay or prevent their formation. For epidermal growth factor receptor mutation-positive (EGFRm) advanced NSCLC and brain metastases, upfront EGFR-tyrosine kinase inhibitors (TKIs) are recommended by the joint European Association of Neuro-Oncology-European Society for Medical Oncology and experts. While early-generation EGFR-TKIs have limited CNS efficacy, the third-generation, irreversible, EGFR-TKI osimertinib has potent efficacy in NSCLC CNS metastases. This review discusses the CNS data of osimertinib in the context of therapeutic strategies and future prospects based on expert review of published literature and relevant clinical, real-world, and ongoing studies in this setting. Osimertinib penetrates the blood-brain barrier and achieves greater exposure in the brain compared with other EGFR-TKIs. Osimertinib has demonstrated CNS efficacy, including in leptomeningeal metastases, in EGFRm advanced disease. In EGFRm stage IB-IIIA NSCLC, adjuvant osimertinib reduced CNS disease recurrence versus placebo. The burden and poor prognosis of CNS metastases necessitate more therapeutic options for their management and reduced risk of recurrence in patients with EGFRm NSCLC. Clinical studies are ongoing in advanced disease to investigate osimertinib combinations with chemotherapy/radiation therapy and optimal treatment post-CNS progression with osimertinib. Further prospective research evaluating treatments using CNS-specific endpoints and evaluating CNS resistance is needed to improve outcomes for patients with CNS metastases.

Brain metastasis as the first and only metastatic relapse site portends worse survival in patients with advanced HER2 + breast cancer

PURPOSE

Current systemic therapy guidelines for patients with HER2 + breast cancer brain metastases (BCBrM) diverge based on the status of extracranial disease (ECD). An in-depth understanding of the impact of ECD on outcomes in HER2 + BCBrM has never been performed. Our study explores the implications of ECD status on intracranial progression-free survival (iPFS) and overall survival (OS) after first incidence of HER2 + BCBrM and radiation.

METHODS

A retrospective analysis was performed of 151 patients diagnosed with initial HER2 + BCBrM who received radiation therapy to the central nervous system (CNS) at Duke between 2008 and 2021. The primary endpoint was iPFS defined as the time from first CNS radiation treatment to intracranial progression or death. OS was defined as the time from first CNS radiation or first metastatic disease to death. Systemic staging scans within 30 days of initial BCBrM defined ECD status as progressive, stable/responding or none (isolated brain relapse).

RESULTS

In this cohort, > 70% of patients had controlled ECD with either isolated brain relapse (27%) or stable/responding ECD (44%). OS from initial metastatic disease to death was markedly worse for patients with isolated intracranial relapse (median = 28.4 m) compared to those with progressive or stable/responding ECD (48.8 m and 71.5 m, respectively, p = 0.0028). OS from first CNS radiation to death was significantly worse for patients with progressive ECD (16.9 m) versus stable/responding (36.6 m) or isolated intracranial relapse (28.4 m, p = 0.007). iPFS did not differ statistically based on ECD status. Receipt of systemic therapy after first BCBrM significantly improved iPFS (HR 0.45, 95% CI: 0.25-0.81, p = 0.008) and OS (HR: 0.43 (95% CI: 0.23-0.81); p = 0.001).

CONCLUSION

OS in patients with HER2 + isolated BCBrM was inferior to those with concurrent progressive or stable/responding ECD. Studies investigating initiation of brain-penetrable HER2-targeted therapies earlier in the disease course of isolated HER2 + intracranial relapse patients are warranted.

Breast Cancer Brain Metastases: Achilles' Heel in Breast Cancer Patients' Care

Brain metastases (BM) significantly affect the prognosis as well as the quality of life of breast cancer (BC) patients. Although advancements in neurosurgical and radiotherapy techniques improve local control and symptom management, BM remains associated with a poor prognosis. In addition, the efficacy of currently approved systemic therapies in central nervous system (CNS) compartment is still limited, especially after progression on local therapy. The blood-brain barrier (BBB) has been recognized as a mechanism of primary resistance to many chemotherapeutic agents and targeted therapies due to low drug penetration. Other mechanisms of primary and secondary resistance are still unclear and may vary across the BC subtypes. New small molecules have demonstrated efficacy in BM, in particular for the HER2-positive subtype, with a benefit in survival. A new era has begun in the field of BM, and many trials specifically designed for this population are currently ongoing. The BC research community needs to address this call with the final aim of improving the efficacy of systemic therapy in CNS compartment and ultimately preventing the occurrence of BM.

Validation and discussion of clinical practicability of the 2022 graded prognostic assessment for NSCLC adenocarcinoma patients with brain metastases in a routine clinical cohort

Introduction

The goal of this analysis is to validate the 2022 graded prognostic assessment (GPA) for patients with brain metastases from adenocarcinoma of the lung and to discuss its clinical practicability.

Methods/material

137 patients with adenocarcinoma of the lung were included in this analysis. The disease specific GPA for NSCLC, Lung-molGPA and the GPA for NSCLC adenocarcinoma were calculated. Overall survival was calculated for each GPA group. Additionally, expected and actual OS in the prognostic groups of the GPA available at the time of the patients' diagnosis was compared.

Results

Median overall survival (OS) from diagnosis of brain metastases was 15 months (95% confidence interval (CI) 9.7-20.3 months). The median OS in the three individual prognostic groups was 7 months for GPA 0-1, 16 months for GPA 1.5-2, 33 months for GPA 2.5-3 and not reached for GPA 3.5-4 (p<0.001). Median survival times for the individual groups were similar to those published in the original GPA publication. Regarding the expected and actual OS when using the available GPA at the time of diagnosis there was an underestimation of survival of more than 3 months for all except the worst prognosis group.

Conclusion

We were able to validate the 2022 GPA for NSCLC adenocarcinoma patients with brain metastases in a similar cohort from a non-academic center. However, the practical applicability regarding the expected median OS might be limited due to the constantly evolving treatment landscape and the consecutive improvement in overall survival.

The role of targeted therapy and immune therapy in the management of non-small cell lung cancer brain metastases

Brain metastases are a significant source of morbidity and mortality in patients with non-small cell lung cancer. Historically, surgery and radiation therapy have been essential to maintaining disease control within the central nervous system due to poorly penetrant conventional chemotherapy. With the advent of targeted therapy against actionable driver mutations, there is potential to control limited and asymptomatic intracranial disease and delay local therapy until progression. In this review paper, intracranial response rates and clinical outcomes to biological and immune therapies are summarized from the literature and appraised to assist clinical decision making and identify areas for further research. Future clinical trials ought to prioritize patient-centered quality of life and neurocognitive measures as major outcomes and specifically stratify patients based on mutational marker status, disease burden, and symptom acuity.

A phase III, multicenter, randomized controlled trial of preoperative versus postoperative stereotactic radiosurgery for patients with surgically resectable brain metastases

BACKGROUND

Postoperative stereotactic radiosurgery (SRS) is a standard management option for patients with resected brain metastases. Preoperative SRS may have certain advantages compared to postoperative SRS, including less uncertainty in delineation of the intact tumor compared to the postoperative resection cavity, reduced rate of leptomeningeal dissemination postoperatively, and a lower risk of radiation necrosis. The recently published ASCO-SNO-ASTRO consensus statement provides no recommendation for the preferred sequencing of radiotherapy and surgery for patients receiving both treatments for their brain metastases.

METHODS

This multicenter, randomized controlled trial aims to recruit 88 patients with resectable brain metastases over an estimated three-year period. Patients with ten or fewer brain metastases with at least one resectable, fulfilling inclusion criteria will be randomized to postoperative SRS (standard arm) or preoperative SRS (investigational arm) in a 1:1 ratio. Randomization will be stratified by age (< 60 versus ≥60 years), histology (melanoma/renal cell carcinoma/sarcoma versus other), and number of metastases (one versus 2-10). In the standard arm, postoperative SRS will be delivered within 3 weeks of surgery, and all unresected metastases will receive primary SRS. In the investigational arm, enrolled patients will receive SRS of all brain metastases followed by surgery of resectable metastases within one week of SRS. In either arm, single fraction or hypofractionated SRS in three or five fractions is permitted. The primary endpoint is to assess local control at 12 months in both arms. Secondary endpoints include local control at other time points, regional/distant brain recurrence rates, leptomeningeal recurrence rates, overall survival, neurocognitive outcomes, and adverse radiation events including radiation necrosis rates in both arms.

DISCUSSION

This trial addresses the unanswered question of the optimal sequencing of surgery and SRS in the management of patients with resectable brain metastases. No randomized data comparing preoperative and postoperative SRS for patients with brain metastases has been published to date.

TRIAL REGISTRATION

Clinicaltrials.gov , NCT04474925; registered on July 17, 2020. Protocol version 1.0 (January 31, 2020).

SPONSOR

Alberta Health Services, Edmonton, Canada (Samir Patel, MD).

Radiotherapeutic Strategies to Overcome Resistance of Breast Cancer Brain Metastases by Considering Immunogenic Aspects of Cancer Stem Cells

Breast cancer is the most diagnosed cancer in women, and symptomatic brain metastases (BCBMs) occur in 15-20% of metastatic breast cancer cases. Despite technological advances in radiation therapy (RT), the prognosis of patients is limited. This has been attributed to radioresistant breast cancer stem cells (BCSCs), among other factors. The aim of this review article is to summarize the evidence of cancer-stem-cell-mediated radioresistance in brain metastases of breast cancer from radiobiologic and radiation oncologic perspectives to allow for the better interpretability of preclinical and clinical evidence and to facilitate its translation into new therapeutic strategies. To this end, the etiology of brain metastasis in breast cancer, its radiotherapeutic treatment options, resistance mechanisms in BCSCs, and effects of molecularly targeted therapies in combination with radiotherapy involving immune checkpoint inhibitors are described and classified. This is considered in the context of the central nervous system (CNS) as a particular metastatic niche involving the blood-brain barrier and the CNS immune system. The compilation of this existing knowledge serves to identify possible synergistic effects between systemic molecularly targeted therapies and ionizing radiation (IR) by considering both BCSCs' relevant resistance mechanisms and effects on normal tissue of the CNS.

The value of stereotactic biopsy of primary and recurrent brain metastases in the era of precision medicine

Background

Brain metastases (BM) represent the most frequent intracranial tumors with increasing incidence. Many primary tumors are currently treated in protocols that incorporate targeted therapies either upfront or for progressive metastatic disease. Hence, molecular markers are gaining increasing importance in the diagnostic framework of BM. In cases with diagnostic uncertainty, both in newly diagnosed or recurrent BM, stereotactic biopsy serves as an alternative to microsurgical resection particularly whenever resection is not deemed to be safe or feasible. This retrospective study aimed to analyze both diagnostic yield and safety of an image-guided frame based stereotactic biopsy technique (STX).

Material and methods

Our institutional neurosurgical data base was searched for any surgical procedure for suspected brain metastases between January 2016 and March 2021. Of these, only patients with STX were included. Clinical parameters, procedural complications, and tissue histology and concomitant molecular signature were assessed.

Results

Overall, 467 patients were identified including 234 (50%) with STX. Median age at biopsy was 64 years (range 29 - 87 years). MRI was used for frame-based trajectory planning in every case with additional PET-guidance in 38 cases (16%). In total, serial tumor probes provided a definite diagnosis in 230 procedures (98%). In 4 cases (1.7%), the pathological tissue did not allow a definitive neuropathological diagnosis. 24 cases had to be excluded due to non-metastatic histology, leaving 206 cases for further analyses. 114 patients (49%) exhibited newly diagnosed BM, while 46 patients (20%) displayed progressive BM. Pseudoprogression was seen in 46 patients, a median of 12 months after prior therapy. Pseudoprogression was always confirmed by clinical course. Metastatic tissue was found most frequently from lung cancer (40%), followed by breast cancer (9%), and malignant melanoma (7%). Other entities included gastrointestinal cancer, squamous cell cancer, renal cell carcinoma, and thyroid cancer, respectively. In 9 cases (4%), the tumor origin could not be identified (cancer of unknown primary). Molecular genetic analyses were successful in 137 out of 144 analyzed cases (95%). Additional next-generation sequencing revealed conclusive results in 12/18 (67%) cases. Relevant peri-procedural complications were observed in 5 cases (2.4%), which were all transient. No permanent morbidity or mortality was noted.

Conclusion

In patients with BM, frame-based stereotactic biopsy constitutes a safe procedure with a high diagnostic yield. Importantly, this extended to discerning pseudoprogression from tumor relapse after prior therapy. Thus, comprehensive molecular characterization based on minimal-invasive stereotactic biopsies lays the foundation for precision medicine approaches in the treatment of primary and recurrent BM.

Automated Detection of Brain Metastases on T1-Weighted MRI Using a Convolutional Neural Network: Impact of Volume Aware Loss and Sampling Strategy

BACKGROUND

Detection of brain metastases (BM) and segmentation for treatment planning could be optimized with machine learning methods. Convolutional neural networks (CNNs) are promising, but their trade-offs between sensitivity and precision frequently lead to missing small lesions.

HYPOTHESIS

Combining volume aware (VA) loss function and sampling strategy could improve BM detection sensitivity.

STUDY TYPE

Retrospective.

POPULATION

A total of 530 radiation oncology patients (55% women) were split into a training/validation set (433 patients/1460 BM) and an independent test set (97 patients/296 BM).

FIELD STRENGTH/SEQUENCE

1.5 T and 3 T, contrast-enhanced three-dimensional (3D) T1-weighted fast gradient echo sequences.

ASSESSMENT

Ground truth masks were based on radiotherapy treatment planning contours reviewed by experts. A U-Net inspired model was trained. Three loss functions (Dice, Dice + boundary, and VA) and two sampling methods (label and VA) were compared. Results were reported with Dice scores, volumetric error, lesion detection sensitivity, and precision. A detected voxel within the ground truth constituted a true positive.

STATISTICAL TESTS

McNemar's exact test to compare detected lesions between models. Pearson's correlation coefficient and Bland-Altman analysis to compare volume agreement between predicted and ground truth volumes. Statistical significance was set at P ≤ 0.05.

RESULTS

Combining VA loss and VA sampling performed best with an overall sensitivity of 91% and precision of 81%. For BM in the 2.5-6 mm estimated sphere diameter range, VA loss reduced false negatives by 58% and VA sampling reduced it further by 30%. In the same range, the boundary loss achieved the highest precision at 81%, but a low sensitivity (24%) and a 31% Dice loss.

DATA CONCLUSION

Considering BM size in the loss and sampling function of CNN may increase the detection sensitivity regarding small BM. Our pipeline relying on a single contrast-enhanced T1-weighted MRI sequence could reach a detection sensitivity of 91%, with an average of only 0.66 false positives per scan.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Stereotactic radiosurgery for limited brain metastasis using three different techniques: helical tomotherapy, volumetric modulated arc therapy, and cone-based LINAC radiosurgery

PURPOSE

Specific radiation delivered to tumors by stereotactic radiosurgery (SRS) has become widely used in the treatment of brain metastasis. This study aimed to compare radiation therapy planning and its parameters from SRS using three different modalities: helical tomotherapy (HT), volumetric modulated arc therapy (VMAT), and cone-based linac radiosurgery (Cone-based).

MATERIALS AND METHODS

Each contouring dataset of patents who experienced one to four brain metastasis received SRS in our center was re-planned to create radiation therapy planning in all three treatment systems (HT, VMAT, and Cone-based). The parameters of conformity index (CI), homogeneity index (HI), CI50, and gradient index (CGI) were analyzed to compare the effects of the three techniques. Decision score analysis was used to evaluate the performance on dosimetric and organs-at-risk parameters among the different techniques by applying the Cone-based technique as a benchmark.

RESULTS

A total of 21 patients with 39 lesions were included in this study. The results from the decision score analysis demonstrated statistically identical CI, CI50, and CGI values between Cone-based and VMAT for single lesions. For multiple lesions, VMAT also provided better CI when compared to Cone-based technique while HT exhibited the poorest dosimetric parameters. Moreover, VMAT exhibited the lowest BrainV5Gy value and displayed the shortest beam-on time calculation.

CONCLUSION

We have conducted a comprehensive comparison of SRS planning approaches. The Cone-based technique revealed the highest HI value, while VMAT provided the best estimated beam-on time value. HT displayed a feasible SRS modality for single lesions, but not for multiple lesions.

Endoscope-assisted visualization of 5-aminolevulinic acid fluorescence in surgery for brain metastases

OBJECTIVE

Fluorescence-guided resection of cerebral metastases has been proposed as an approach to visualize residual tumor tissue and maximize the extent of resection. Critics have argued that tumor cells at the resection margins might be overlooked under microscopic visualization because of technical limitations. Therefore, an endoscope, which is capable of inducing fluorescence, has been applied with the aim of improving exposure of fluorescent tumor tissue. In this retrospective analysis, authors assessed the utility of endoscope assistance in 5-aminolevulinic acid (5-ALA) fluorescence-guided resection of brain metastases.

METHODS

Between June 2013 and December 2016, a standard 20-mg/kg dose of 5-ALA was administered 4 hours prior to surgery in 26 patients with suspected single brain metastases. After standard neuronavigated microsurgical tumor resection, a microscope capable of inducing fluorescence was used to examine tumor margins. The authors classified the remaining fluorescence into 3 grades (0 = none, 1 = weak, and 2 = strong). Endoscopic assistance was employed if no or only weak fluorescence was visualized at the resection margins under the microscope. Endoscopically identified fluorescent tissue at the margins was resected and evaluated separately via histological examination to prove or disprove tumor infiltration.

RESULTS

Under the microscope, weakly fluorescent tissue was seen at the margins of the resection cavity in 15/26 (57.7%) patients. In contrast, endoscopic inspection revealed strongly fluorescent tissue in 22/26 (84.6%) metastases. In 11/26 (42.3%) metastases no fluorescence at the tumor margins was detected by the microscope; however, strong fluorescence was visualized under the endoscope in 7 (63.6%) of these 11 metastases. In the 15 metastases with microscopically weak fluorescence, strong fluorescence was seen when using the endoscope. Neither microscopic nor endoscopic fluorescence was found in 4/26 (15.4%) cases. In the 26 patients, 96 histological specimens were obtained from the margins of the resection cavity. Findings from these specimens were in conjunction with the histopathological findings, allowing identification of metastatic infiltration with a sensitivity of 95.5% and a specificity of 75% using endoscope assistance.

CONCLUSIONS

Fluorescence-guided endoscope assistance may overcome the technical limitations of the conventional microscopic exposure of 5-ALA-fluorescent metastases and thereby increase visualization of fluorescent tumor tissue at the margins of the resection cavity with high sensitivity and acceptable specificity.

Genomic Profiling Identifies Putative Pathogenic Alterations in NSCLC Brain Metastases

Introduction

Brain metastases (BM) severely affect the prognosis and quality of life of patients with NSCLC. Recently, molecularly targeted agents were found to have promising activity against BM in patients with NSCLC whose primary tumors carry "druggable" mutations. Nevertheless, it remains critical to identify specific pathogenic alterations that drive NSCLC-BM and that can provide novel and more effective therapeutic targets.

Methods

To identify potentially targetable pathogenic alterations in NSCLC-BM, we profiled somatic copy number alterations (SCNAs) in 51 matched pairs of primary NSCLC and BM samples from 33 patients with lung adenocarcinoma and 18 patients with lung squamous cell carcinoma. In addition, we performed multiregion copy number profiling on 15 BM samples and whole-exome sequencing on 40 of 51 NSCLC-BM pairs.

Results

BM consistently had a higher burden of SCNAs compared with the matched primary tumors, and SCNAs were typically homogeneously distributed within BM, suggesting BM do not undergo extensive evolution once formed. By comparing focal SCNAs in matched NSCLC-BM pairs, we identified putative BM-driving alterations affecting multiple cancer genes, including several potentially targetable alterations in genes such as CDK12, DDR2, ERBB2, and NTRK1, which we validated in an independent cohort of 84 BM samples. Finally, we identified putative pathogenic alterations in multiple cancer genes, including genes involved in epigenome editing and 3D genome organization, such as EP300, CTCF, and STAG2, which we validated by targeted sequencing of an independent cohort of 115 BM samples.

Conclusions

Our study represents the most comprehensive genomic characterization of NSCLC-BM available to date, paving the way to functional studies aimed at assessing the potential of the identified pathogenic alterations as clinical biomarkers and targets.