Phase III comparison of prophylactic cranial irradiation versus observation in patients with locally advanced non-small-cell lung cancer: primary analysis of radiation therapy oncology group study RTOG 0214

An improved 3D-UNet-based brain hippocampus segmentation model based on MR images

OBJECTIVE

Accurate delineation of the hippocampal region via magnetic resonance imaging (MRI) is crucial for the prevention and early diagnosis of neurosystemic diseases. Determining how to accurately and quickly delineate the hippocampus from MRI results has become a serious issue. In this study, a pixel-level semantic segmentation method using 3D-UNet is proposed to realize the automatic segmentation of the brain hippocampus from MRI results.

METHODS

Two hundred three-dimensional T1-weighted (3D-T1) nongadolinium contrast-enhanced magnetic resonance (MR) images were acquired at Hangzhou Cancer Hospital from June 2020 to December 2022. These samples were divided into two groups, containing 175 and 25 samples. In the first group, 145 cases were used to train the hippocampus segmentation model, and the remaining 30 cases were used to fine-tune the hyperparameters of the model. Images for twenty-five patients in the second group were used as the test set to evaluate the performance of the model. The training set of images was processed via rotation, scaling, grey value augmentation and transformation with a smooth dense deformation field for both image data and ground truth labels. A filling technique was introduced into the segmentation network to establish the hippocampus segmentation model. In addition, the performance of models established with the original network, such as VNet, SegResNet, UNetR and 3D-UNet, was compared with that of models constructed by combining the filling technique with the original segmentation network.

RESULTS

The results showed that the performance of the segmentation model improved after the filling technique was introduced. Specifically, when the filling technique was introduced into VNet, SegResNet, 3D-UNet and UNetR, the segmentation performance of the models trained with an input image size of 48 × 48 × 48 improved. Among them, the 3D-UNet-based model with the filling technique achieved the best performance, with a Dice score (Dice score) of 0.7989 ± 0.0398 and a mean intersection over union (mIoU) of 0.6669 ± 0.0540, which were greater than those of the original 3D-UNet-based model. In addition, the oversegmentation ratio (OSR), average surface distance (ASD) and Hausdorff distance (HD) were 0.0666 ± 0.0351, 0.5733 ± 0.1018 and 5.1235 ± 1.4397, respectively, which were better than those of the other models. In addition, when the size of the input image was set to 48 × 48 × 48, 64 × 64 × 64 and 96 × 96 × 96, the model performance gradually improved, and the Dice scores of the proposed model reached 0.7989 ± 0.0398, 0.8371 ± 0.0254 and 0.8674 ± 0.0257, respectively. In addition, the mIoUs reached 0.6669 ± 0.0540, 0.7207 ± 0.0370 and 0.7668 ± 0.0392, respectively.

CONCLUSION

The proposed hippocampus segmentation model constructed by introducing the filling technique into a segmentation network performed better than models built solely on the original network and can improve the efficiency of diagnostic analysis.

Machine-Learning-Aided Prediction of Brain Metastases Development in Non-Small-Cell Lung Cancers

PURPOSE

Non-small-cell lung cancer (NSCLC) shows a high incidence of brain metastases (BM). Early detection is crucial to improve clinical prospects. We trained and validated classifier models to identify patients with a high risk of developing BM, as they could potentially benefit from surveillance brain MRI.

METHODS

Consecutive patients with an initial diagnosis of NSCLC from January 2011 to April 2019 and an in-house chest-CT scan (staging) were retrospectively recruited at a German lung cancer center. Brain imaging was performed at initial diagnosis and in case of neurological symptoms (follow-up). Subjects lost to follow-up or still alive without BM at the data cut-off point (12/2020) were excluded. Covariates included clinical and/or 3D-radiomics-features of the primary tumor from staging chest-CT. Four machine learning models for prediction (80/20 training) were compared. Gini Importance and SHAP were used as measures of importance; sensitivity, specificity, area under the precision-recall curve, and Matthew's Correlation Coefficient as evaluation metrics.

RESULTS

Three hundred and ninety-five patients compromised the clinical cohort. Predictive models based on clinical features offered the best performance (tuned to maximize recall: sensitivity∼70%, specificity∼60%). Radiomics features failed to provide sufficient information, likely due to the heterogeneity of imaging data. Adenocarcinoma histology, lymph node invasion, and histological tumor grade were positively correlated with the prediction of BM, age, and squamous cell carcinoma histology were negatively correlated. A subgroup discovery analysis identified 2 candidate patient subpopulations appearing to present a higher risk of BM (female patients + adenocarcinoma histology, adenocarcinoma patients + no other distant metastases).

CONCLUSION

Analysis of the importance of input features suggests that the models are learning the relevant relationships between clinical features/development of BM. A higher number of samples is to be prioritized to improve performance. Employed prospectively at initial diagnosis, such models can help select high-risk subgroups for surveillance brain MRI.

Genomic Alterations and the Incidence of Brain Metastases in Advanced and Metastatic NSCLC: A Systematic Review and Meta-Analysis

INTRODUCTION

Brain metastases (BMs) in patients with advanced and metastatic NSCLC are linked to poor prognosis. Identifying genomic alterations associated with BM development could influence screening and determine targeted treatment. We aimed to establish prevalence and incidence in these groups, stratified by genomic alterations.

METHODS

A systematic review and meta-analysis compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were conducted (PROSPERO identification CRD42022315915). Articles published in MEDLINE, EMBASE, and Cochrane Library between January 2000 and May 2022 were included. Prevalence at diagnosis and incidence of new BM per year were obtained, including patients with EGFR, ALK, KRAS, and other alterations. Pooled incidence rates were calculated using random effects models.

RESULTS

A total of 64 unique articles were included (24,784 patients with NSCLC with prevalence data from 45 studies and 9058 patients with NSCLC having incidence data from 40 studies). Pooled BM prevalence at diagnosis was 28.6% (45 studies, 95% confidence interval [CI]: 26.1-31.0), and highest in patients that are ALK-positive (34.9%) or with RET-translocations (32.2%). With a median follow-up of 24 months, the per-year incidence of new BM was 0.13 in the wild-type group (14 studies, 95% CI: 0.11-0.16). Incidence was 0.16 in the EGFR group (16 studies, 95% CI: 0.11-0.21), 0.17 in the ALK group (five studies, 95% CI: 0.10-0.27), 0.10 in the KRAS group (four studies, 95% CI: 0.06-0.17), 0.13 in the ROS1 group (three studies, 95% CI: 0.06-0.28), and 0.12 in the RET group (two studies, 95% CI: 0.08-0.17).

CONCLUSIONS

Comprehensive meta-analysis indicates a higher prevalence and incidence of BM in patients with certain targetable genomic alterations. This supports brain imaging at staging and follow-up, and the need for targeted therapies with brain penetrance.

What is the current role of prophylactic cranial irradiation in the treatment algorithm for small cell lung cancer?

Prophylactic cranial irradiation (PCI) is considered an important technological advance made in oncology in an effort to reduce the incidence of brain metastases (BM) and improve overall survival (OS) of patients with small cell lung cancer (SCLC). Although it is often reported that PCI improves the therapeutic potential in limited-stage (LS) SCLC, no randomised trial has ever conclusively confirmed this. Nevertheless, PCI has been considered the standard of care for LS-SCLC since the late 1990s. The data supporting the use of PCI in LS-SCLC are based on an analysis of work performed prior to the current approach to staging [brain magnetic resonance imaging (MRI), positron emission tomography (PET)/computed tomography (CT)]. The evidence for the rationale and feasibility of this approach in the modern diagnostic era should be demonstrated. The situation with extensive stage (ES) SCLC is seemingly easier because, unlike LS-SCLC, we have data from two randomised trials. Unfortunately, their results are in direct conflict with each other. Although it is generally assumed that good control of brain disease leads to better quality of life, this has never been prospectively demonstrated. In fact, PCI is associated not only with increased treatment costs and some patient discomfort, but also with non-negligible potential toxicity. For this reason, efforts have been made to preserve cognitive function by sparing the hippocampus. This concept is called hippocampal avoidance. The optimal fractionation regimen is currently less controversial than the optimal integration of PCI into the treatment algorithm. A dose of 25 Gy administered in 10 fractions should remain the standard for the eventual use of PCI in patients with SCLC. In summary, PCI is not a conditio sine qua non in any indication. Neither in patients with LS-SCLC nor in patients with ES-SCLC has a clear improvement in OS been demonstrated at follow-up using current imaging modalities.

Perihippocampal Meningeal Carcinomatosis Following Hippocampal Avoidance Prophylactic Cranial Irradiation in Small Cell Lung Cancer: A Case Report

Prophylactic cranial irradiation (PCI) for limited disease small cell lung cancer is the standard of care for curative treatment of this disease. However, neurocognitive dysfunction is one of the late adverse events of PCI and is often problematic. Recently, hippocampal avoidance prophylactic cranial irradiation (HA-PCI) is sometimes performed to prevent neurocognitive dysfunction after PCI. In HA-PCI, the question is whether or not metastases appear around the hippocampus that were not irradiated. We have experienced a case of perihippocampal meningeal carcinomatosis after HA-PCI. We also draw attention to the potential risks of performing HA-PCI based on this experience.

A "Seed-and-Soil" Radiomics Model Predicts Brain Metastasis Development in Lung Cancer: Implications for Risk-Stratified Prophylactic Cranial Irradiation

Introduction: Brain is a major site of metastasis for lung cancer, and effective therapy for developed brain metastasis (BM) is limited. Prophylactic cranial irradiation (PCI) has been shown to reduce BM rate and improve survival in small cell lung cancer, but this result was not replicated in unselected non-small cell lung cancer (NSCLC) and had the risk of inducing neurocognitive dysfunctions. We aimed to develop a radiomics BM prediction model for BM risk stratification in NSCLC patients. Methods: 256 NSCLC patients with no BM at baseline brain magnetic resonance imaging (MRI) were selected; 128 patients developed BM within three years after diagnosis and 128 remained BM-free. For radiomics analysis, both the BM and non-BM groups were randomly distributed into training and testing datasets at an 70%:30% ratio. Both brain MRI (representing the soil) and chest computed tomography (CT, representing the seed) radiomic features were extracted to develop the BM prediction models. We first developed the radiomic models using the training dataset (89 non-BM and 90 BM cases) and subsequently validated the models in the testing dataset (39 non-BM and 38 BM cases). A radiomics BM score (RadBM score) was generated, and BM-free survival were compared between RadBM score-high and RadBM score-low groups. Results: The radiomics model developed from baseline brain MRI features alone can predict BM development in NSCLC patients. A fusion model integrating brain MRI features with primary tumor CT features (seed-and-soil model) provided synergetic effect and was more efficient in predicting BM (areas under the receiver operating characteristic curve 0.84 (95% confidence interval: 0.80−0.89) and 0.80 (95% confidence interval: 0.71−0.88) in the training and testing datasets, respectively). BM-free survival was significantly shorter in the RadBM score-high group versus the RadBM score-low group (Log-rank, p < 0.001). Hazard ratios for BM were 1.056 (95% confidence interval: 1.044−1.068) per 0.01 increment in RadBM score. Cumulative BM rates at three years were 75.8% and 24.2% for the RadBM score-high and RadBM score-low groups, respectively. Only 1.2% (7/565) of the BM lesions were located within the hippocampal avoidance region. Conclusion: The results demonstrated that intrinsic features of a non-metastatic brain exert a significant impact on BM development, which is first-in-class in metastasis prediction studies. A radiomics BM prediction model utilizing both primary tumor and pre-metastatic brain features might provide a useful tool for individualized PCI administration in NSCLC patients more prone to develop BM.

Real-world risk of brain metastases in stage III non-small cell lung cancer in the era of PET and MRI staging

Objective

The 2-year incidence of brain metastases (BrMs) in stage III non-small lung cell cancer (NSCLC) has been estimated to be around 30%. However, recent clinical trials have demonstrated considerably lower BrMs rates in this patient population. In this study, we aimed to review the real-world incidence, surveillance, and treatment patterns of BrMs in stage III NSCLC.

Materials and methods

Using a retrospective single-center study design, we identified patients with stage III NSCLC who received radiation with curative intent over a 10-year period. Outcome variables included BrMs incidence, overall survival (OS), and survival from date of BrMs. Additionally, we assessed patterns of BrMs surveillance in stage III NSCLC and treatment.

Results

We identified a total of 279 stage III NSCLC patients, of which 160 with adequate records were included in the final analyses [adenocarcinoma (n = 96), squamous cell carcinoma (n = 53), other histology subtype (n = 11)]. The median OS for the entire cohort was 41 months (95% CI, 28-53), while the median time from BrMs to death was 19 months (95% CI, 9-21). Twenty-three patients (14.4%) received planned surveillance brain MRIs at 6, 12, and 24 months after completion of treatment. The remaining 137 patients (85.6%) received brain MRIs at systemic recurrence (restaging) or when neurologically symptomatic. A total of 37 patients (23%) developed BrMs, with a 2-year cumulative BrMs incidence of 17% (95% CI, 11-23). A higher incidence of BrMs was identified in patients with adenocarcinoma relative to those with squamous cell carcinoma (p < 0.01). Similarly, a higher 2-year BrMs incidence was observed in patients who received planned surveillance brain MRI relative to those who did not, although statistical significance was not reached. Stereotactic radiosurgery (SRS) treated 29 of BrMs patients (78.4%) and was preferred over WBRT, which treated only 3 patients (8.1%).

Conclusions

At our center, BrMs incidence in stage III NSCLC patients was lower than historically reported but notably higher than the incidence described in recent clinical trials. Routine BrMs surveillance potentially allows earlier detection of asymptomatic BrMs. However, asymptomatic BrMs were mostly detected on restaging MRI at the time of recurrence.

Nano-scale simulation of neuronal damage by galactic cosmic rays

The effects of realistic, deep space radiation environments on neuronal function remain largely unexplored.In silicomodeling studies of radiation-induced neuronal damage provide important quantitative information about physico-chemical processes that are not directly accessible through radiobiological experiments. Here, we present the first nano-scale computational analysis of broad-spectrum galactic cosmic ray irradiation in a realistic neuron geometry. We constructed thousands ofin silicorealizations of a CA1 pyramidal neuron, each with over 3500 stochastically generated dendritic spines. We simulated the entire 33 ion-energy beam spectrum currently in use at the NASA Space Radiation Laboratory galactic cosmic ray simulator (GCRSim) using the TOol for PArticle Simulation (TOPAS) and TOPAS-nBio Monte Carlo-based track structure simulation toolkits. We then assessed the resulting nano-scale dosimetry, physics processes, and fluence patterns. Additional comparisons were made to a simplified 6 ion-energy spectrum (SimGCRSim) also used in NASA experiments. For a neuronal absorbed dose of 0.5 Gy GCRSim, we report an average of 250 ± 10 ionizations per micrometer of dendritic length, and an additional 50 ± 10, 7 ± 2, and 4 ± 2 ionizations per mushroom, thin, and stubby spine, respectively. We show that neuronal energy deposition by proton andα-particle tracks declines approximately hyperbolically with increasing primary particle energy at mission-relevant energies. We demonstrate an inverted exponential relationship between dendritic segment irradiation probability and neuronal absorbed dose for each ion-energy beam. We also find that there are no significant differences in the average physical responses between the GCRSim and SimGCRSim spectra. To our knowledge, this is the first nano-scale simulation study of a realistic neuron geometry using the GCRSim and SimGCRSim spectra. These results may be used as inputs to theoretical models, aid in the interpretation of experimental results, and help guide future study designs.

Epidermal growth factor receptor mutations and brain metastases in non-small cell lung cancer

Studies have revealed that non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations has a high incidence of brain metastases (BMs). However, the association between EGFR mutations and BMs remains unknown. This review summarizes detailed information about the incidence of BMs, clinical and imaging characteristics of BMs, brain surveillance strategies, influence of treatments on BMs, prognosis after BMs, and differences in EGFR mutations between paired primary tumors and BMs in EGFR-mutated NSCLC. The prognostic results demonstrate that patients with mutated EGFR have a higher incidence of BMs, EGFR tyrosine kinase inhibitors (EGFR-TKIs) (afatinib and osimertinib) delay the development of BMs, and patients with mutated EGFR with synchronous or early BMs have better overall survival after BMs than those with wild-type EGFR. The EGFR mutation status of BM sites is not always in accordance with the primary tumors, which indicates that there is heterogeneity in EGFR gene status between paired primary tumors and BMs. However, the EGFR gene status of the primary site can largely represent that of BM sites. Among patients developing synchronous BMs, patients with mutated EGFR are less likely to have central nervous system (CNS) symptoms than patients with wild-type EGFR. However, the possibility of neuro-symptoms is high in patients with metachronous BMs. Patients with mutated EGFR tend to have multiple BMs as compared to patients with wild-type EGFR. Regarding very early-stage NSCLC patients without neuro-symptoms, regular neuroimaging follow-up is not recommended. Among advanced NSCLC patients with EGFR mutation, liberal brain imaging follow-up in the first several years showed more advantages in terms of cost.

Predictive value of baseline metabolic tumor burden on 18F-FDG PET/CT for brain metastases in patients with locally advanced non-small-cell lung cancer

OBJECTIVES

Brain metastases (BMs) are a major cause leading to the failure of treatment management for non-small-cell lung cancer (NSCLC) patients. The purpose of this study was to evaluate the predictive value of baseline metabolic tumor burden on 18F-FDG PET/CT measured with metabolic tumor volume (MTV) and total lesion glycolysis (TLG) for brain metastases (BMs) development in patients with locally advanced non-small-cell lung cancer (NSCLC) after treatment.

METHODS

Forty-seven patients with stage IIB-IIIC NSCLC who underwent baseline 18F-FDG PET/CT examinations were retrospectively reviewed. The maximum standardized uptake value (SUVmax), MTV, and TLG of the primary tumor (SUVmaxT, MTVT, and TLGT), metastatic lymph nodes (SUVmaxN, MTVN, and TLGN), and whole-body tumors (SUVmaxWB, MTVWB, and TLGWB) were measured. The optimal cut-off values of PET parameters to predict brain metastasis-free survival were obtained using Receiver operating characteristic (ROC) analysis, and the predictive value of clinical variables and PET parameters were evaluated using Cox proportional hazards regression analysis.

RESULTS

The median follow-up duration was 25.0 months for surviving patients, and 13 patients (27.7%) developed BM. The optimal cut-off values were 21.1 mL and 150.0 g for MTVT and TLGT, 20.0, 10.9 mL and 55.6 g for SUVmaxN, MTVN and TLGN, and 27.9, 27.4 mL and 161.0 g for SUVmaxWB, MTVWB and TLGWB, respectively. In the Cox proportional hazards models, the risk of BM was significantly associated with MTVN and MTVWB or TLGN and TLGWB after adjusting for histological cell type, N stage, SUVmaxN, and SUVmaxWB.

CONCLUSIONS

Baseline metabolic tumor burden (MTV and TLG) evaluated from the level of metastatic lymph nodes and whole-body tumors are significant predictive factors for BM development in patients with locally advanced NSCLC.

Quality of Life and Cognitive Function Evaluations and Interventions for Patients with Brain Metastases in the Radiation Oncology Clinic

Simple Summary

Brain metastases (BMs) are the most common brain malignancy and are projected to increase in incidence over the coming decades. Historically, brain metastasis studies have focused on improving survival outcomes, but recently, the importance of evaluating health-related quality of life (HRQOL) and cognitive function has gained recognition. Although there is a myriad of validated HRQOL and cognitive assessments available in the radiation oncology clinic, there is an urgent need to identify tools tailored to patients with BMs and to adopt a uniform set of tests that measure HRQOL and cognition. This review presents various assessments for measuring HRQOL and cognitive function, current recommendations to improve standardization, and treatments known to preserve HRQOL and cognitive function.

Abstract

Brain metastases (BMs) account for a disproportionately high percentage of cancer morbidity and mortality. Historically, studies have focused on improving survival outcomes, and recent radiation oncology clinical trials have incorporated HRQOL and cognitive assessments. We are now equipped with a battery of assessments in the radiation oncology clinic, but there is a lack of consensus regarding how to incorporate them in modern clinical practice. Herein, we present validated assessments for BM patients, current recommendations for future clinical studies, and treatment advances that have improved HRQOL and cognitive outcomes for BM patients.

Improved Survival With Surgical Treatment of Primary Lung Lesions in Non-Small Cell Lung Cancer With Brain Metastases: A Propensity‐Matched Analysis of Surveillance, Epidemiology, and End Results Database

Objectives

Non-small cell lung cancer (NSCLC) with Brain metastases (BM) is an advanced disease with poor prognosis and low survival rate. Our study evaluated the survival benefit of primary lung resection with mediastinal lymph node dissection in NSCLC patients with BM using Surveillance, Epidemiology, and End-result (SEER) databases.

Methods

All cases analyzed were from Surveillance, Epidemiology, and End Results database. The data of the patients with BM of NSCLC from 2010 to 2016 was retrospectively analyzed. Patients (N=203) patients who underwent radical surgical treatment for primary lung lesions and patients (N=15500) who did not undergo surgery were compared. We successfully analyzed patients using propensity score matching (PSM). Kaplan‐Meier and Cox‐ regression analyses were applied to assess prognosis.

Results

The median survival in the surgery group was longer than in the control group (27 months vs 5 months; P &lt; 0.001) in the overall sample, 21 months longer compared to the control group (27 months vs 6 months; P&lt;0.001) in a PSM cohort. Cox regression analysis showed that underwent surgery patients in the propensity-matched sample had a significantly lower risk of mortality (HR:0.243, 95%CI: 0.162-0.365, P &lt; 0.001) compared with untreated patients. Multivariate analysis identified the following as independent risk factors for NSCLC with BM: no primary resection surgery, age &gt;65 years, worse differentiation, squamous cell carcinoma, lymphatic metastasis, no systemic therapy. Subgroup analysis revealed that radical resection of the primary lung provided a survival benefit regardless of marital status, tumor size, tumor grade, tumor T stage, and mediastinal lymph node metastasis after PSM.

Conclusion

Radical resection of primary lung can improve the survival of NSCLC patients with BM. Male, age&gt;65years, poorly differentiated tumor, tumor size&gt;5cm, and mediastinal lymph node metastasis were factors for poor survival.

Complex survival trial design by the product integration method

Nonproportional hazards (NPHs) are often observed in survival trials such as the immunotherapy cancer trials. Under NPH, the classical log-rank test can be inefficient, and the estimated hazards ratio from the Cox model is difficult to interpret. The weighted log-rank test, and the tests for comparing the restricted mean survival time or the milestone survival become increasingly popular in handling NPH. The sample size calculation for these tests may require high-dimensional numerical integration. We present a sample size determination method for survival trials via product integration on the basis of a continuous-time multistate Markov model. The main challenge of the method lies in the design of the multistate model under a complex NPH pattern, and this is illustrated for NPH induced by delayed effect with individual heterogeneity in the lag duration, cure fractions, and treatment switching due to disease progression or noncompliance. Numerical examples are presented to demonstrate the accuracy of the proposed method. We obtain the following findings. The powers of the tests for milestone survival and RMST depend on both the trial duration and milestone timepoint, and may not increase as the milestone timepoint increases. If the milestone timepoint is appropriately chosen, the RMST test can be more powerful than the conventional log-rank test in the presence of diminishing treatment effect or in the proportional hazards cure model. In general, the RMST test yields lower power than a proper Fleming-Harrington weighted log-rank test.

Management of brain metastases in lung cancer: evolving roles for radiation and systemic treatment in the era of targeted and immune therapies

Brain metastases are a common occurrence in both non-small cell and small cell lung cancer with the potential to affect quality of life and prognosis. Due to concerns about the accessibility of the central nervous system by systemic chemotherapy agents, the management of brain metastases has historically relied on local therapies including surgery and radiation. However, novel targeted and immune therapies that improve overall outcomes in lung cancer have demonstrated effective intracranial activity. As a result, the management of brain metastases in lung cancer has evolved, with both local and systemic therapies now playing an important role. Factors such as tumor histology (non-small versus small cell), oncogenic driver mutations, and symptom burden from intracranial disease impact treatment decisions. Here, we review the current management of brain metastases in lung cancer, highlighting the roles of stereotactic radiosurgery and novel systemic therapies as well as the ongoing questions that remain under investigation.

Modern Radiation Therapy for the Management of Brain Metastases From Non-Small Cell Lung Cancer: Current Approaches and Future Directions

Brain metastases (BMs) represent the most frequent event during the course of Non-Small Cell Lung Cancer (NSCLC) disease. Recent advancements in the diagnostic and therapeutic procedures result in increased incidence and earlier diagnosis of BMs, with an emerging need to optimize the prognosis of these patients through the adoption of tailored treatment solutions. Nowadays a personalized and multidisciplinary approach should rely on several clinical and molecular factors like patient’s performance status, extent and location of brain involvement, extracranial disease control and the presence of any “druggable” molecular target. Radiation therapy (RT), in all its focal (radiosurgery and fractionated stereotactic radiotherapy) or extended (whole brain radiotherapy) declinations, is a cornerstone of BMs management, either alone or combined with surgery and systemic therapies. Our review aims to provide an overview of the many modern RT solutions available for the treatment of BMs from NSCLC in the different clinical scenarios (single lesion, oligo and poly-metastasis, leptomeningeal carcinomatosis). This includes a detailed review of the current standard of care in each setting, with a presentation of the literature data and of the possible technical solutions to offer a “state-of-art” treatment to these patients. In addition to the validated treatment options, we will also discuss the future perspectives on emerging RT technical strategies (e.g., hippocampal avoidance whole brain RT, simultaneous integrated boost, radiosurgery for multiple lesions), and present the innovative and promising findings regarding the combination of novel targeted agents such as tyrosine kinase inhibitors and immune checkpoint inhibitors with brain irradiation.

Association of different fractionation schedules for prophylactic cranial irradiation with toxicity and brain metastases-free survival in stage III non-small cell lung cancer: A pooled analysis of individual patient data from three randomized trials

We assessed the impact of different PCI fractionation schedules (30 Gy in 10 versus 15 fractions) on brain metastases-free survival (BMFS) and toxicity in stage III NSCLC. Our results suggest that 30 Gy in 10 fractions is associated with increased toxicity, while no conclusive evidence of improving BMFS was seen with this schedule.

Successful salvage of recurrent leptomeningeal disease in large cell neuroendocrine lung cancer with stereotactic radiotherapy

A 70-year old male with stage I large cell neuroendocrine carcinoma (LCNEC) of the lung underwent resection of a metachronous 5 cm brain metastasis and received postoperative hypofractionated stereotactic radiotherapy (hfSRT). Five sequential nodular leptomeningeal metastases up to 5.3 cm in diameter were diagnosed on MRI within 10 months and were treated with SRT. Currently the patient has no evidence of intracranial disease 24 months after last irradiation without chemotherapy or whole brain radiotherapy. This is the first report of sustained complete remission of multiple large leptomeningeal metastases achieved with hfSRT, highlighting this brain-sparing approach in selected patients with LCNEC lung cancer.

Randomized Phase III Trial of Prophylactic Cranial Irradiation With or Without Hippocampal Avoidance for Small-Cell Lung Cancer (PREMER): A GICOR-GOECP-SEOR Study

PURPOSE

Radiation dose received by the neural stem cells of the hippocampus during whole-brain radiotherapy has been associated with neurocognitive decline. The key concern using hippocampal avoidance-prophylactic cranial irradiation (HA-PCI) in patients with small-cell lung cancer (SCLC) is the incidence of brain metastasis within the hippocampal avoidance zone.

METHODS

This phase III trial enrolled 150 patients with SCLC (71.3% with limited disease) to standard prophylactic cranial irradiation (PCI; 25 Gy in 10 fractions) or HA-PCI. The primary objective was the delayed free recall (DFR) on the Free and Cued Selective Reminding Test (FCSRT) at 3 months; a decrease of 3 points or greater from baseline was considered a decline. Secondary end points included other FCSRT scores, quality of life (QoL), evaluation of the incidence and location of brain metastases, and overall survival (OS). Data were recorded at baseline, and 3, 6, 12, and 24 months after PCI.

RESULTS

Participants' baseline characteristics were well balanced between the two groups. The median follow-up time for living patients was 40.4 months. Decline on DFR from baseline to 3 months was lower in the HA-PCI arm (5.8%) compared with the PCI arm (23.5%; odds ratio, 5; 95% CI, 1.57 to 15.86; P = .003). Analysis of all FCSRT scores showed a decline on the total recall (TR; 8.7% v 20.6%) at 3 months; DFR (11.1% v 33.3%), TR (20.3% v 38.9%), and total free recall (14.8% v 31.5%) at 6 months, and TR (14.2% v 47.6%) at 24 months. The incidence of brain metastases, OS, and QoL were not significantly different.

CONCLUSION

Sparing the hippocampus during PCI better preserves cognitive function in patients with SCLC. No differences were observed with regard to brain failure, OS, and QoL compared with standard PCI.

Prophylactic Cranial Irradiation in Patients With High-Risk Metastatic Non-Small Cell Lung Cancer: Quality of Life and Neurocognitive Analysis of a Randomized Phase II Study

PURPOSE

To this date, studies regarding the use of prophylactic cranial irradiation (PCI) versus standard of care (SoC) for patients with non-small cell lung cancer have shown limited benefit in survival outcomes, in addition to the potential effects on quality of life (QoL) and neurocognitive function (NCF). This randomized, phase II study evaluated the role of PCI in QoL and NCF, in a population comprised of subjects at a high risk for development of brain metastases (BM).

METHODS AND MATERIALS

Eligible patients had histologically confirmed non-small cell lung cancer without baseline BM, harboring epidermal growth factor receptor mutations, anaplastic lymphoma kinase rearrangements, or elevated carcinoembryonic antigen (CEA) at diagnosis. Participants were assigned to receive SoC or SoC plus PCI (25 Gy in 10 fractions). Primary endpoint was BM at 24 months (BM-24), for which the study was powered. Secondary endpoints included QoL assessed using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) and the Lung Cancer module (LC13) and NCF assessed using the Mini Mental State Examination (MMSE). Patients were followed every 3 months for a year for QoL and NCF.

RESULTS

From May 2012 to December 2017, 84 patients were enrolled in the study, 41 were allocated to PCI while 43 received SoC. Efficacy outcomes are discussed in a separate article. The global health-QoL scores were similar at 3, 6, 9, and 12 months after randomization between both study arms, with no significant differences when comparing by groups. At 1-year postrandomization, median global health QoL scores were 83 (p25-p75: 75-83) and 83 (p25-p75: 75-83) in the control and experimental arms, respectively. There were no significant changes in terms of the mean differences between subjects in either study arm when analyzing the change between baseline and 12-month scores (16.4 ± 19.9 vs 12.9 ± 14.7; P = .385). Seventeen patients were alive at database lockdown in February 2020, without significant differences in median MMSE (30 [p25-75: 29-30] vs 30 [p25-75: 28-30]) or QLQ-C30 scores (75.0 [p25-75: 50-87.2] vs 67.0 [p25-75: 50.0-100.0]).

CONCLUSIONS

Among a selected high-risk population for developing BM, PCI did not significantly decrease QoL or neurocognitive function as assessed using the MMSE. Future studies are warranted to assess this observation, using more varied and sensitive tools available to date.

Individual patient data meta-analysis of prophylactic cranial irradiation in locally advanced non-small cell lung cancer

BACKGROUND

Prophylactic cranial irradiation (PCI) was compared to observation in several randomized trials (RCTs), and a reduction greater than 50% was shown regarding the incidence of brain metastases (BM). However, none of these studies showed an improvement of overall survival (OS), possibly related to relatively small sample sizes and short follow-up. The aim of this meta-analysis was therefore to assess the impact of PCI on long term OS for stage III non-small cell lung cancer (NSCLC) compared to observation based on the pooled updated individual patient RCT data.

METHODS

Seven RCTs were eligible, and data from the four most recent trials (924 patients) could be retrieved. The log-rank observed minus expected number of events and its variance were used to calculate individual and overall pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) with a fixed effects model. Inter-trial heterogeneity was studied using the I² test. In addition, the 5-year absolute survival difference between arms was calculated for all endpoints. The pre-specified toxicities were reported descriptively.

RESULTS

The median follow-up was 97 months (74-108). Compared to observation, no statistically significant impact of PCI on OS was observed (HR 0.90 [0.76-1.07] p = 0.23, 5-year absolute difference 1.8% [-5.2-8.8]). PCI significantly prolonged progression-free survival (HR 0.77 [0.66-0.91] p = 0.002) and BM-free survival (HR 0.82 [0.69-0.97] p = 0.02). The number of patients with high-grade (≥3) toxicity was 6.4% (21/330) for PCI.

CONCLUSION

No OS benefit by PCI was observed, but PCI prolonged the progression-free survival and BM-free survival at an increased risk of late memory impairment and fatigue.

Advances in Lung Cancer Driver Genes Associated With Brain Metastasis

Brain metastasis, one of the common complications of lung cancer, is an important cause of death in patients with advanced cancer, despite progress in treatment strategies. Lung cancers with positive driver genes have higher incidence and risk of brain metastases, suggesting that driver events associated with these genes might be biomarkers to detect and prevent disease progression. Common lung cancer driver genes mainly encode receptor tyrosine kinases (RTKs), which are important internal signal molecules that interact with external signals. RTKs and their downstream signal pathways are crucial for tumor cell survival, invasion, and colonization in the brain. In addition, new tumor driver genes, which also encode important molecules closely related to the RTK signaling pathway, have been found to be closely related to the brain metastases of lung cancer. In this article, we reviewed the relationship between lung cancer driver genes and brain metastasis, and summarized the mechanism of driver gene-associated pathways in brain metastasis. By understanding the molecular characteristics during brain metastasis, we can better stratify lung cancer patients and alert those at high risk of brain metastasis, which helps to promote individual therapy for lung cancer.

Deep learning-based automatic delineation of the hippocampus by MRI: geometric and dosimetric evaluation

BACKGROUND

Whole brain radiotherapy (WBRT) can impair patients' cognitive function. Hippocampal avoidance during WBRT can potentially prevent this side effect. However, manually delineating the target area is time-consuming and difficult. Here, we proposed a credible approach of automatic hippocampal delineation based on convolutional neural networks.

METHODS

Referring to the hippocampus contouring atlas proposed by RTOG 0933, we manually delineated (MD) the hippocampus on the MRI data sets (3-dimensional T1-weighted with slice thickness of 1 mm, n = 175), which were used to construct a three-dimensional convolutional neural network aiming for the hippocampus automatic delineation (AD). The performance of this AD tool was tested on three cohorts: (a) 3D T1 MRI with 1-mm slice thickness (n = 30); (b) non-3D T1-weighted MRI with 3-mm slice thickness (n = 19); (c) non-3D T1-weighted MRI with 1-mm slice thickness (n = 11). All MRIs confirmed with normal hippocampus has not been violated by any disease. Virtual radiation plans were created for AD and MD hippocampi in cohort c to evaluate the clinical feasibility of the artificial intelligence approach. Statistical analyses were performed using SPSS version 23. P < 0.05 was considered significant.

RESULTS

The Dice similarity coefficient (DSC) and Average Hausdorff Distance (AVD) between the AD and MD hippocampi are 0.86 ± 0.028 and 0.18 ± 0.050 cm in cohort a, 0.76 ± 0.035 and 0.31 ± 0.064 cm in cohort b, 0.80 ± 0.015 and 0.24 ± 0.021 cm in cohort c, respectively. The DSC and AVD in cohort a were better than those in cohorts b and c (P < 0.01). There is no significant difference between the radiotherapy plans generated using the AD and MD hippocampi.

CONCLUSION

The AD of the hippocampus based on a deep learning algorithm showed satisfying results, which could have a positive impact on improving delineation accuracy and reducing work load.

Can we define any marker associated with brain failure in patients with locally advanced non-small cell lung cancer?

PURPOSE

To define the factors which may be related to brain metastasis (BM) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who developed brain metastases after definitive treatment.

PATIENTS AND METHODS

A total of 208 patients with LA-NSCLC, without BM who received definitive radiotherapy (RT) or RT+chemotherapy (CT) between January 2005 and January 2016 were evaluated retrospectively. Platelet, neutrophil, lymphocyte counts, LDH, CRP, Hb levels, neutrophil-to-lymphocyte radio (NLR), platelet-to-lymphocyte radio (PLR), advanced lung cancer inflammation index (ALI) and FDG-PET/CT parameters (SUVmax of the primary tumor and mediastinal lymph nodes), and patient characteristics were evaluated for brain metastasis free survival (BMFS).

RESULTS

Median follow-up duration was 25 months (range: 3-130months). Cut-off values for platelet, NLR, PLR, LDH, CRP, and Hb were 290×103/μL, 2.6, 198, 468 IU/L, 2.5mg/dL, and 11.5g/dl. We defined each parameter as low or high according to the cut-off values. 56 patients (26.9%) developed brain metastases during follow-up. In univariate analysis, high NLR (P=0.001), PLR (P=0.037), LDH (P=0.028), CRP (P=0.002) values, value ≥7.5 for lymph nodes (P=0.005) and low ALI value (P=0.002) were poor prognostic factors for BMFS. In multivariate analysis, high NLR (P=0.022), PLR (P=0.017), CRP (P=0.006), stage ≥IIIB disease (P<0.001), multi-stational N2 disease (P=0.036), adenocarcinoma histology (P<0.001) and SUVmax value ≥7.5 (P=0.035) were poor prognostic factors for BMFS.

CONCLUSIONS

High NLR, PLR, LDH, CRP values, SUVmax values for lymph nodes, and low ALI which indicates high tumor burden were additional prognostic factors besides stage, histology, and lymph node status.

CT-based radiomics for predicting brain metastases as the first failure in patients with curatively resected locally advanced non-small cell lung cancer

PURPOSE

Brain metastasis (BM) is the primary first failure pattern in patients with curatively resected locally advanced non-small cell lung cancer (LA-NSCLC). It is not yet possible to accurately predict the occurrence of BM. The purpose of the research is to develop and validate a prediction model of BM-free survival based on radiomics characterising the primary lesions combined with clinical characteristics in patients with curatively resected LA-NSCLC.

METHODS

This study consisted of 124 patients with curatively resected stage IIB-IIIB NSCLC in our institution between January 2014 and June 2018. Patients were randomly divided into training and validation cohorts using a 4:1 ratio. Radiomics features were selected from the chest CT images before surgery. A radiomics signature was constructed using the LASSO algorithm based on the training cohort. Clinical model was developed using the Cox proportional hazards model. The clinical, radiomics, and integrated nomograms were constructed. The prediction performance of the models was assessed based on its discrimination, calibration, and clinical utility.

RESULTS

The radiomics signature is significantly associated with BM-free survival in the overall cohort. The discrimination performance of the integrated nomogram, with the C-indexes 0.889 (0.872-0.906, 95 % CI) and 0.853 (0.788-0.918, 95 % CI) in the training and validation cohorts, respectively, is significantly better than the clinical nomogram (p < 0.0001 for the training cohort, p = 0.0008 for the validation cohort). Compared with the radiomics nomogram, the integrated nomogram is also improved to varying degrees, but not apparent in the validation cohort (p = 0.0007 for the training cohort, p = 0.0554 for the validation cohort). The calibration curve and decision curve analysis demonstrated that the integrated nomogram exceeded the clinical or radiomics nomograms in predicting BM-free survival.

CONCLUSIONS

Compared with the clinical or radiomics nomograms, the predictive performance of the integrated nomogram is significantly improved. The integrated nomogram is most suitable for predicting BM-free survival in patients with curatively resected LA-NSCLC.

Trimodality therapy for superior sulcus tumour: experience of a single institution over 19 years

OBJECTIVES

Induction chemoradiotherapy followed by surgery is the standard treatment for superior sulcus tumours (SSTs). However, the protocols, chemotherapy agents and cycles used as well as the mode and intensity of radiotherapy vary between institutions. Thus, the objective of the study was to investigate the effects of trimodality therapy on the outcomes of patients with SSTs.

METHODS

Sixty patients with SSTs were enrolled between January 1999 and December 2017. Induction therapy consisted primarily of 2 cycles of mitomycin-vindesine-cisplatin or cisplatin-vinorelbine delivered concurrently to the tumour with 40-45 Gy of radiation. Surgery was performed 2-6 weeks after completion of induction therapy.

RESULTS

Fifty-four (90%) patients underwent radical surgical resection. Complete pathological resection was achieved in 44 patients (81%). There was no 30-day mortality. After a median follow-up of 57.0 months, 19 (35%) patients experienced recurrence, and 8 (15%) patients showed brain metastasis. A pathological complete response (PCR) was observed in 12 (22%) patients. The 5-year survival rate for the entire population (n = 54) was 69% (95% confidence interval 55-81%). The survival rate was better for patients who underwent complete resection than for those who underwent incomplete resection (73% vs 51%, P = 0.46). A better survival rate was evident in patients with PCR than in those without PCR (92% vs 62%, P = 0.12).

CONCLUSIONS

Trimodality therapy for SSTs was efficacious and associated with favourable outcomes, with acceptable morbidity and mortality. PCR in patients with resected SSTs reveals promising long-term survival prospects with the trimodality therapy.

Nintedanib and a bi-specific anti-VEGF/Ang2 nanobody selectively prevent brain metastases of lung adenocarcinoma cells

Brain metastases (BM) are an ever-increasing challenge in oncology, threatening quality of life and survival of many cancer patients. The majority of BM originate from lung adenocarcinoma, and stage III patients have a risk of 40–50% to develop BM in the first years of disease onset. As therapeutic options are limited, prevention of their occurrence is an attractive concept. Here we investigated whether Nintedanib (BIBF 1120), a tyrosine kinase inhibitor (TKI) targeting the VEGF pathway approved for lung adenocarcinoma, and the dual anti-VEGF-A/Ang2 nanobody BI836880 have the potential to prevent BM formation. A mouse model of brain metastasis from lung adenocarcinoma was used in which tumor cells were injected intracardially. Metastases formation occurred inside and outside of the brain and was followed by MRI, IVIS, and immunohistochemistry. BM were reduced in volume and number by both Nintedanib and the dual anti-VEGF-A/Ang2 nanobody, which translated into improved survival. Both compounds were able to normalize cerebral blood vessels at the site of brain metastatic lesions. Extracranial metastases, however, were not reduced, and meningeal metastases only partially. Interestingly, unspecific control IgG also lead to brain vessel normalization and reduction of brain and meningeal metastases. This data indicates a brain-specific group effect of antiangiogenic compounds with respect to metastasis prevention, most likely by preventing an early angiogenic switch. Thus, Nintedanib and BI836880 are promising candidates for future BM preventive study concepts in lung adenocarcinoma patients.

Treatment and toxic effects of prophylactic cranial irradiation in stage II-III non-small cell lung cancer: A meta-analysis

OBJECTIVE

To determine the role of prophylactic cranial irradiation (PCI) in non-small cell lung cancer (NSCLC) patients using meta-analysis.

METHODS

PubMed, Embase, the Cochrane Database of Systematic Review and the China National Knowledge Infrastructure databases were systematically searched for studies published between 1 January 1980 and 31 March 2019. Search terms included "non-small cell lung cancer," "prophylactic cranial irradiation" and "clinical trials." The research data extracted from above studies was analyzed by Review Manager 5.3 and Stata12.0 software. The outcomes included development of brain metastases (BMs), overall survival (OS), disease-free survival (DFS), BMs for different diagnoses, toxicity, quality of life (QoL).

RESULTS

Fifteen trials (nine RCTs and six non-RCTs) involving 2418 NSCLC patients met the inclusion criteria. There was a significant reduction in the risk of developing BM in patients who received PCI compared with those who did not (95% CI, 0.20-0.37; P < 0.00001). PCI significantly reduced the BM of squamous cell carcinoma (P = 0.02), but not for adenocarcinoma (P = 0.07) and other pathological types (P = 0.29). There was a significant increase in DFS for the PCI compared to the non-PCI group (P = 0.006); however, OS did not significantly differ (P = 0.15). In addition, fatigue significantly increased in the PCI group (P = 0.0002). Cognitive disturbance showed no significant difference between PCI and non-PCI groups (P = 0.06).

CONCLUSION

This study showed that, compared with non-PCI, PCI significantly decreased the incidence of NSCLC BM and improved the DFS of patients, and reduced the BM rate from squamous cell carcinoma. However, it showed no effect on OS and the BM rate of adenocarcinoma and other pathological types of tumors. There were limited data concerning PCI-related toxicity and QoL.

Risk factors of metachronous brain metastasis in patients with EGFR-mutated advanced non-small cell lung cancer

Background

NSCLC patients with EGFR mutation were at a higher incidence of developing brain metastasis (BM). Patients with BM are associated with high mortality. Reducing BM incidence becomes increasingly significant for NSCLC patients to achieve prolonged survival. The aim of the study was to explore the possible risk factors of developing metachronous BM during EGFR-TKIs treatment, and to identify the potential candidates for prophylactic cranial irradiation (PCI) or the first-line Osimertinib treatment.

Methods

A total of 157 consecutive EGFR-mutated advanced NSCLC patients without BM at initial diagnosis in our institution from 2012 and 2018 were retrospectively reviewed. Comparisons of OS were performed based on BM status. The cumulative incidence of metachronous BM was calculated by the Kaplan-Meier method, and the independent risk factors of metachronous BM were investigated by multivariate analysis.

Results

Patients developing metachronous BM had worse survival (mOS: 22.1 months) than patients not-developing BM (mOS: 44.8 months). Moreover, the multivariate analysis indicated that age ≤ 49 years (P = 0.035), number of extracranial metastases (P = 0.013), and malignant pleural effusion (P = 0.002) were independent risk factors of metachronous BM. Furthermore, the 1-year actuarial incidence of developing metachronous BM in patients with no risk factor (n = 101), 1 risk factor (n = 46), and 2 risk factors (n = 10) were 7.01, 14.61, and 43.75%, respectively (P < 0.001).

Conclusions

Patients developing metachronous BM during EGFR-TKIs treatment have worse outcomes. Our results suggested that EGFR-mutated advanced NSCLC patients with ≥1 risk factors were candidates for PCI or the first-line Osimertinib treatment.

Incidence of hippocampal metastases in non-small-cell lung cancer

OBJECTIVES

Patients with locally advanced non-small-cell lung cancer (LA-NSCLC) develop brain metastases in 25-50% of cases during the course of their disease. Data on the incidence of metastases occurring in the hippocampus/perihippocampal zones are limited. This is important when considering hippocampal-sparing brain radiation (HS-BR), a method that could potentially reduce the neurocognitive impact of such treatment. The aim of this study was to assess the incidence of hippocampal/perihippocampal metastases in a cohort of patients with advanced NSCLC treated at our institution.

METHODS

This retrospective cohort study included NSCLC patients discussed at our institutional lung cancer multidisciplinary meeting between 2000 and 2016. MRI and contrast-enhanced CT (ceCT) brain images were reviewed to assess the incidence of hippocampal/perihippocampal metastases including metastases within the hippocampal subgranular zone and a 5 mm margin (hippocampal avoidance region) defined as per the RTOG 0933 study.

RESULTS

Of 2146 patients reviewed, 357 (16.6%) had brain metastases. A total of 335 patients had available MRI/ceCT brain images for review. Thirty (9%) patients had brain metastases in the hippocampal avoidance region, 8 (2.4%) with hippocampal metastases and 22 (6.6%) with perihippocampal metastases. Univariate analyses did not show an association between developing metastases in the hippocampal avoidance region and age (P = 0.75), gender (P = 0.91) and tumour type (P = 0.298).

CONCLUSION

The incidence of metastases in the hippocampal avoidance region in our large cohort of patients was 9%. With low rates of metastases in this region, HS-BR can be considered a feasible option in the management of patients with advanced NSCLC.

Predicting brain metastasis in early stage non-small cell lung cancer patients by gene expression profiling

Background

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-death due to early metastatic spread, in many cases primarily to the brain. Organ-specific pattern of spread of disease might be driven by the activity of a specific signaling pathway within the primary tumors. We aimed to identify an expression signature of genes and the relevant signaling associated with the development of brain metastasis (BM) after surgical resection of NSCLC.

Methods

Rapidly frozen NSCLC surgical specimens were procured from tumor banks. RNA was extracted and analyzed by RNA-sequencing (Illumina HiSeq 2500). Clinical parameters and gene expression were examined for differentiating between patients with BM, patients with metastases to sites other than brain, and patients who did not develop metastatic disease at a clinically significant follow up. Principal component analysis and pathway enrichments studies were done.

Results

A total of 91 patients were included in this study, 32 of which developed BM. Stage of disease at diagnosis (P=0.004) and level of differentiation (P=0.007) were significantly different between BM and control group. We identified a set of 22 genes which correlated specifically with BM, and not with metastasis to other sites. This set achieved 93.4% accuracy (95% CI: 86.2–97.5%), 96.6% specificity and 87.5% sensitivity of correctly identifying BM patients in a leave-one-out internal validation analysis. The oxidative phosphorylation pathway was strongly correlated with BM risk.

Conclusions

Expression level of a small set of genes from primary tumors was found to predict BM development, distinctly from metastasis to other organs. These genes and the correlated oxidative phosphorylation pathway require further validation as potentially clinically useful predictors of BM and possibly as novel therapeutic targets for BM prevention.

Risk factors for neurocognitive decline in lung cancer patients treated with prophylactic cranial irradiation: A systematic review

BACKGROUND

Prophylactic cranial irradiation (PCI) reduces brain metastasis incidence in lung cancer, however with risk of neurocognitive decline. Nevertheless, risk factors for neurocognitive decline after PCI remain unclear.

METHODS

We systematically reviewed the PubMed database according to the PRISMA guideline. Inclusion criteria were: randomized clinical trials (RCTs) and observational/single arm trials evaluating PCI, including ≥20 patients, reporting neurocognitive test results for lung cancer. Primary aim: evaluate risk factors associated with neurocognitive decline after PCI.

RESULTS

Twenty records were eligible (8 different RCTs, 8 observational studies), including 3553 patients in total (858 NSCLC, 2695 SCLC) of which 73.6% received PCI. Incidence of mild/moderate cognitive decline after PCI varied from 8 to 89% (grading not always provided); for those without PCI, this was 3.4-42%. Interestingly, 23-95% had baseline cognitive impairment. Risk factors were often not reported. In one trial, both age (>60 years) and higher PCI dose (36 Gy) including twice-daily PCI were associated with a higher risk of cognitive decline. In one trial, white matter abnormalities were more frequent in the concurrent or sandwiched PCI arm, but without significant neuropsychological differences. One trial identified hippocampal sparing PCI to limit the neurocognitive toxicities of PCI and another reported an association between hippocampal dose volume effects and memory decline. As neurocognition was a secondary endpoint in most RCTs, and was assessed by various instruments with often poor/moderate compliance, high-quality data is lacking.

CONCLUSIONS

Age, PCI dose, regimen and timing might be associated with cognitive impairment after PCI in lung cancer patients, but high-quality data is lacking. Future PCI trials should collect and evaluate possible risk factors systematically.

Strategies to prevent brain metastasis

PURPOSE OF REVIEW

The current article reviews the state of art of prevention strategies for brain metastases from solid tumors and touches both old pivotal studies and new directions of personalized molecular approaches.

RECENT FINDINGS

Prophylactic cranial irradiation (PCI) has a definite role in the prevention of relapse into the brain for patients with small cell lung cancer (SCLC) responding to chemotherapy and radiotherapy as it prolongs overall survival (OS). However, the risk of late cognitive deficit following whole brain radiotherapy (WBRT) in this patient population is still not well known. Conversely, PCI significantly reduces the incidence of brain metastases and prolongs the disease-free interval in patients with non-SCLC (NSCLC), but does not improve OS thus far. Pharmacologic prevention is a new concept driven by the efficacy of targeted agents on macrometastases from specific molecular subgroups.

SUMMARY

The future challenges for prevention of brain metastases are represented by the identification of subgroups of patients at higher risk of relapse into the brain coupled with either new WBRT strategies to better preserve cognition or effective molecular agents to target micrometastases.

Risk factors of brain metastases as initial failure in completely resected stage IIIA(N2) non-small cell lung cancer

Background

This study aimed to identify the risk factors of brain metastases (BM) as the initial site of failure in patients with completely resected stage IIIA (N2) non-small-cell lung cancer (NSCLC).

Methods

From January 2005 and June 2012, the clinical data of 357 patients with completely resected stage IIIA (N2) NSCLC were reviewed in this study. Kaplan-Meier analysis was used to identify the incidence of BM as the initial site of failure and survival. To assess the risk factors of BM, the log-rank test and Cox regression were used for univariate analysis and multivariate analysis, separately.

Result

Seventy-three (20.4%) patients developed BM; 60 patients had BM as their initial site of failure. The 1-, 3-, and 5-year risk for patients developing BM as the initial site of failure was 9.1%, 27.4% and 35.4%, respectively. Univariate analysis showed adenocarcinoma histology (P=0.000), number of regional LN >4 (P=0.018), multiple N2 stations (P=0.027), multiple region of LN involvement (P=0.010) were significantly associated with an increased risk of developing BM as the initial site of failure. Multivariate analysis showed adenocarcinoma (P=0.001; HR =0.150; 95% CI, 0.047–0.479), multiple regions of LN involvement (P=0.015; HR =2.010; 95% CI, 1.146–3.524) were significantly associated with the high risk of developing BM as the initial site of failure. In patients with adenocarcinoma and multiple regions of LN involvement, the 5-year actuarial risk of BM as the initial failure was 47.6%, respectively.

Conclusions

Adenocarcinoma and multiple regions of LN involvement were independent risk factors for BM as the initial failure in completely resected stage IIIA (N2) NSCLC. Prospective clinical trials are needed to verify the effect of PCI in the highest-risk subset we identified.

Prophylactic Cranial Irradiation vs Observation in Patients With Locally Advanced Non-Small Cell Lung Cancer: A Long-term Update of the NRG Oncology/RTOG 0214 Phase 3 Randomized Clinical Trial

Importance

Brain metastasis (BM) rates are high in locally advanced non-small cell lung cancer (LA-NSCLC), approaching rates seen in small cell lung cancer, where prophylactic cranial irradiation (PCI) is standard of care. Although PCI decreases the incidence of BM in LA-NSCLC, a survival advantage has not yet been shown.

Objective

To determine if PCI improves survival in LA-NSCLC.

Design, Setting, and Participants

Radiation Therapy Oncology Group (RTOG) 0214 was a randomized phase 3 clinical trial in stage III NSCLC stratified by stage (IIIA vs IIIB), histologic characteristics (nonsquamous vs squamous) and therapy (no surgery vs surgery). The study took place at 291 institutions in the United States, Canada, and internationally. Of 356 patients with stage III NSCLC entered onto this study, 16 were ineligible; therefore, 340 patients were randomized.

Intervention for Clinical Trials

Observation vs PCI.

Main Outcomes and Measures

The primary outcome was overall survival (OS). The secondary end points were disease-free survival (DFS) and incidence of BM.

Results

Of the 340 total participants, mean (SD) age was 61 years; 213 of the participants were men and 127 were women. The median follow-up time was 2.1 years for all patients, and 9.2 years for living patients. The OS for PCI was not significantly better than observation (hazard ratio [HR], 0.82; 95% CI, 0.63-1.06; P = .12; 5- and 10-year rates, 24.7% and 17.6% vs 26.0% and 13.3%, respectively), while the DFS (HR, 0.76; 95% CI, 0.59-0.97; P = .03; 5- and 10-year rates, 19.0% and 12.6% vs 16.1% and 7.5% for PCI vs observation) and BM (HR, 0.43; 95% CI, 0.24-0.77; P = .003; 5- and 10-year rates, 16.7% vs 28.3% for PCI vs observation) were significantly different. Patients in the PCI arm were 57% less likely to develop BM than those in the observation arm. Younger patients (<60 years) and patients with nonsquamous disease developed more BM. On multivariable analysis, PCI was associated with decreased BM and improved DFS, but not improved OS. Multivariable analysis within the nonsurgical arm suggests that PCI effectively prolongs OS, DFS, and BM.

Conclusions and Relevance

In patients with stage III LA-NSCLC without progression of disease after therapy, PCI decreased the 5- and 10-year rate of BM and improved 5- and 10-year DFS, but did not improve OS. Although this study did not meet its primary end point, the long-term results reveal many important findings that will benefit future trials. Identifying the appropriate patient population and a safe intervention is critical.

Trial Registration

ClinicalTrials.gov identifier: NCT00048997.

Risk stratification of symptomatic brain metastases by clinical and FDG PET parameters for selective use of prophylactic cranial irradiation in patients with extensive disease of small cell lung cancer

PURPOSE

To identify risk factors for developing symptomatic brain metastases and evaluate the impact of prophylactic cranial irradiation (PCI) on brain metastasis-free survival (BMFS) and overall survival (OS) in extensive disease small cell lung cancer (ED-SCLC).

MATERIALS AND METHODS

Among 190 patients diagnosed with ED-SCLC who underwent FDG PET/CT and brain Magnetic Resonance Imaging (MRI) prior to treatment, 53 (27.9%) received PCI while 137 (72.1%) did not. Prognostic index predicting a high risk of symptomatic brain metastases was calculated for the group without receiving PCI (observation group, n = 137) with Cox regression model.

RESULTS

Median follow-up time was 10.6 months. Multivariate Cox regression showed that the following three factors were associated with a high risk of symptomatic brain metastases: the presence of extrathoracic metastases (p = 0.004), hypermetabolism of bone marrow or spleen on FDG PET (p < 0.001), and high neutrophil-to-lymphocyte ratio (p = 0.018). PCI significantly improved BMFS in high-risk patients (1-year rate: 94.7% vs. 62.1%, p = 0.001), but not in low-risk patients (1-year rate: 100.0% vs. 87.7%, p = 0.943). However, PCI did not improve OS in patients at high risk for symptomatic brain metastases (1-year rate: 65.2% vs. 50.0%, p = 0.123).

CONCLUSION

Three prognostic factors (the presence of extrathoracic metastases, hypermetabolism of bone marrow or spleen on FDG PET, and high neutrophil-to-lymphocyte ratio) were associated with a high risk of symptomatic brain metastases in ED-SCLC. PCI was beneficial for patients at a high risk of symptomatic brain metastases in terms of BMFS, but not OS. Thus, selective use of PCI in ED-SCLC according to the risk stratification is recommended.

Outcomes of whole-brain radiation with simultaneous in-field boost (SIB) for the treatment of brain metastases

PURPOSE

Prospective studies have demonstrated increased local control with the addition of a radiosurgery (SRS) boost to whole-brain irradiation (WBRT) in patients with brain metastases. However, the clinical application of SRS boost can be limited by several factors, including tumor size, numbers of lesions, and high cost of care. Here, we investigate the use of WBRT with a simultaneous integrated boost (SIB) to visible lesions in patients with brain metastases.

MATERIALS

From 2011 to 2016, patients were prospectively enrolled and prescribed a dose of 25 or 37.5 Gray (Gy) WBRT with a SIB dose of 45 or 52.5 Gy to the gross lesions in 10 or 15 fractions, respectively. All plans were optimized for dose coverage of the whole brain and lesions using volumetric arc therapy (VMAT). Comprehensive neurocognitive and quality of life assessments were conducted at baseline and at follow-up.

RESULTS

Thirteen patients were treated on this protocol. The 1-year local control rates were 92% at the patient level, and 98.6% at the lesion level. The overall 1-year intracranial control was 46%. Patients had no significant declines in Mini-Mental State Examination (MMSE), Hopkins Verbal Learning Test-Revised (HVLT-R), and Medical Outcomes Study (MOS) Cognitive Functional status scores pre- and post-treatment.

CONCLUSION

WBRT with SIB to gross lesions using VMAT planning appears to be safe and effective in the treatment of brain metastases without significant cognitive decline. This treatment strategy should be considered in those patients with a high number of metastases or ones not amenable for radiosurgery.

CLINICAL TRIAL REGISTRATION CODE

NCT01218542.

Nitroglycerin as a radiosensitizer in non-small cell lung cancer: Results of a prospective imaging-based phase II trial

•

Nitroglycerin didn’t improve overall survival of NSCLC patients.

•

The toxicity of combining nitroglycerin with standard treatment was mild.

•

Increased uptake of HX4 showed negative prognostic significance in NSCLC patients.

•

Tumor perfusion after nitroglycerin treatment did not correlate with outcome.

Background

Nitroglycerin is proposed as an agent to reduce tumour hypoxia by improving tumour perfusion. We investigated the potential of nitroglycerin as a radio-sensitizer in non-small cell lung cancer (NSCLC) and the potential of functional imaging for patient selection.

Material and methods

Trial NCT01210378 is a single arm phase II trial, designed to detect 15% improvement in 2-year overall survival (primary endpoint) in stage IB-IV NSCLC patients treated with radical (chemo-) radiotherapy and a Transiderm-Nitro 5 patch during radiotherapy. Patients underwent dynamic contrast-enhanced CTs (DCE-CT) and HX4 (hypoxia) PET/CTs before and after nitroglycerin. Secondary endpoints were progression-free survival, toxicity and the prognostic value of tumour perfusion/hypoxia at baseline and after nitroglycerin.

Results

The trial stopped after a futility analysis after 42 patients. At median follow-up of 41 months, two-year and median OS were 58% (95% CI: 44–78%) and 38 months (95% CI: 22–54 months), respectively. Nitroglycerin could not reduce tumour hypoxia. DCE-CT parameters did not correlate with OS, whereas hypoxic tumours had a worse OS (p = 0.029). Changes in high-uptake fraction of HX4 and tumour blood flow were negatively correlated (r = -0.650, p = 0.022). The heterogeneity in treatment modalities and patient characteristics combined with a small sample size made further subgroup analysis of survival results impossible. Toxicity related to nitroglyerin was limited to headache (17%) and hypotension (2.4%).

Conclusion

Nitroglycerin did not improve OS of NSCLC patients treated with (chemo-)radiotherapy. A general ability of nitroglycerin to reduce hypoxia was not shown.

Lung Cancer Surveillance After Definitive Curative-Intent Therapy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on radiographic imaging and biomarker surveillance strategies after definitive curative-intent therapy in patients with stage I-III non-small-cell lung cancer (NSCLC) and SCLC.

METHODS

ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, radiology, primary care, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2019. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 14 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Patients should undergo surveillance imaging for recurrence every 6 months for 2 years and then annually for detection of new primary lung cancers. Chest computed tomography imaging is the optimal imaging modality for surveillance. Fluorodeoxyglucose positron emission tomography/computed tomography imaging should not be used as a surveillance tool. Surveillance imaging may not be offered to patients who are clinically unsuitable for or unwilling to accept further treatment. Age should not preclude surveillance imaging. Circulating biomarkers should not be used as a surveillance strategy for detection of recurrence. Brain magnetic resonance imaging should not be used for routine surveillance in stage I-III NSCLC but may be used every 3 months for the first year and every 6 months for the second year in patients with stage I-III small-cell lung cancer who have undergone curative-intent treatment.

MicroRNA-330-3p promotes brain metastasis and epithelial-mesenchymal transition via GRIA3 in non-small cell lung cancer

Brain metastasis (BM) is associated with poor prognosis in patients with non-small cell lung cancer (NSCLC). We sought to identify microRNAs (miRNAs) that could serve as biomarkers to differentiate NSCLC patients with and without BM. Logistic regression was conducted with 122 NSCLC patients (60 without BM, 62 with BM) to assess the association between miRNAs and BM. We confirmed several risk factors for BM and revealed that serum miR-330-3p levels are higher in NSCLC patients with BM than that without BM. Overexpression of miR-330-3p promoted proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of NSCLC cells in vitro and NSCLC tumorigenesis in vivo. Knocking down miR-330-3p suppressed this metastatic phenotype. We identified putative miR-330-3p target genes by comparing mRNA microarray analysis data from A549 cells after miR-330-3p knockdown with candidate miR-330-3p target genes predicted by public bioinformatic tools and luciferase reporter assays. We found that GRIA3 is a target of miR-330-3p and that miR-330-3p stimulates EMT progress by mediating GRIA3-TGF-β1 interaction. Our results provide novel insight into the role of miR-330-3p in NSCLC metastasis, and suggest miR-330-3p may be a useful biomarker for identifying NSCLC with metastatic potential.

Development and validation of nomograms for predicting survival probability of patients with advanced adenocarcinoma in different EGFR mutation status

INTRODUCTION

Molecular markers are important variables in the selection of treatment for cancer patients and highly associated with their survival. Therefore, a nomogram that can predict survival probability by incorporating epidermal growth factor receptor mutation status and treatments for patients with advanced adenocarcinoma would be highly valuable. The aim of the study is to develop and validate a novel nomogram, incorporating epidermal growth factor receptor mutation status and treatments, for predicting 1-year and 2-year survival probability of patients with advanced adenocarcinoma.

MATERIAL AND METHODS

Data on 13,043 patients between June 1, 2011, and December 31, 2014 were collected. Seventy percent of them were randomly assigned to the training cohort for nomogram development, and the remaining 30% assigned to the validation cohort. The most important factors for constructing the nomogram were identified using multivariable Cox regression analysis. The discriminative ability and calibration of the nomograms were tested using C-statistics, calibration plots, and Kaplan-Meier curves.

RESULTS

In the training cohort, 1-year and 2-year OS were 52.8% and 28.5% in EGFR(-) patients, and 73.9% and 44.1% in EGFR(+) patients, respectively. In EGFR(+) group, factors selected were age, gender, congestive heart failure, renal disease, number of lymph node examined, tumor stage, surgical intervention, radiotherapy, first-line chemotherapy, ECOG performance status, malignant pleural effusion, and smoking. In EGFR(-) group, factors selected were age, gender, myocardial infarction, cerebrovascular disease, chronic pulmonary disease, number of lymph node examined, tumor stage, surgical intervention, radiotherapy, ECOG performance status, malignant pleural effusion, and a history of smoking. Two nomograms show good accuracy in predicting OS, with a concordance index of 0.83 in EGFR(+) and of 0.88 in EGFR(-).

CONCLUSIONS

The survival prediction models can be used to make individualized predictions with different EGFR mutation status and a useful tool for selecting regimens for treating advanced adenocarcinoma.

Differential Relapse Patterns for Non-small Cell Lung Cancer Subtypes Adenocarcinoma and Squamous Cell Carcinoma: Implications for Radiation Oncology

AIMS

Curative-intent (radical) radiotherapy aims to control local disease and cure non-small cell lung cancer (NSCLC). The predominant subtypes of NSCLC are adenocarcinoma and squamous cell carcinoma (SCC). The radiotherapy paradigm offered to patients does not differ according to these two subtypes. Relapse patterns and disease control rates for adenocarcinoma and SCC treated with radical radiotherapy were determined.

MATERIALS AND METHODS

A radical radiotherapy database covering the period from 2004 to June 2016 was examined to determine the first sites of relapse and the actuarial local and distant control rates.

RESULTS

In total, 537 patients with known pathological subtype were treated over the period. In 39 (7%), the site of first relapse was uncertain. Of the remainder, 203 (41%) had adenocarcinoma and 295 (59%) had SCC. At a median follow-up of 16.4 months, 58% had relapsed. There was a difference in relapse patterns (chi-squared test P < 0.0005), with a higher rate of first relapse locally in SCC (42% of all patients versus 24%) and a higher rate of first relapse in the brain for adenocarcinoma (14% versus 3%). The actuarial local control rate was worse for SCC (hazard ratio 0.6, 95% confidence interval 0.5-0.9, P = 0.002). The brain metastasis-free survival was worse for adenocarcinoma (hazard ratio 4.1, 95% confidence interval 2.2-7.5, P < 0.0001).

CONCLUSION

There is a difference in relapse patterns between NSCLC histological subtypes, indicating that these are distinct entities. This may have implications for follow-up policy and strategies to improve disease control.

Outcomes of patients with disease recurrence after treatment for locally advanced non-small cell lung cancer detected by routine follow-up CT scans versus a symptom driven evaluation

OBJECTIVES

The majority of patients with locally advanced non-small cell lung cancer (LANSCLC) will recur after receiving multimodal treatment with curative intent. Current guidelines recommend routine follow-up with computerized tomography (CT) scans, though minimal data exist on the utility of this approach nor has an optimal follow-up strategy to detect recurrence been defined. This study examined whether survival varied if relapse was detected with scheduled follow-up CT versus symptoms, and whether the pattern of recurrence affected these outcomes.

MATERIALS AND METHODS

Single institution retrospective review of patients who had undergone definitive management of LANSCLC with chemoradiotherapy +/- surgical resection. Standard follow-up testing consisted of routine exam and chest CT beginning at every 3 months in the first year and decreasing to annually after the fifth year.

RESULTS

311 patients were assessed, of which 167 patients recurred and were evaluable. 104 progressions were detected by follow-up and 63 by symptoms. For the entire group, there was no difference in overall survival (OS) for those detected by scans vs. symptoms (7.6 vs. 6.1 months, p = 0.797). After excluding patients with oligometastatic (1-3) brain metastases (OBM), OS was superior in patients with scan detected relapse (7.5 vs. 3.4 months, p = 0.013).

CONCLUSIONS

Routine surveillance by CT chest detects more localized disease than symptom driven follow-up, though OS does not differ. This null result is largely driven by the favorable outcomes for patients with OBM who present symptomatically. A strategy of both chest and brain imaging could be considered and warrants further investigation.

Interdisciplinary multimodality management of stage III nonsmall cell lung cancer

Stage III nonsmall cell lung cancer (NSCLC) comprises about one-third of NSCLC patients and is very heterogeneous with varying and mostly poor prognosis. It is also called "locoregionally or locally advanced disease". Due to its heterogeneity a general schematic management approach is not appropriate. Usually a combination of local therapy (surgery or radiotherapy, depending on functional, technical and oncological operability) with systemic platinum-based doublet chemotherapy and, recently, followed by immune therapy is used. A more aggressive approach of triple agent chemotherapy or two local therapies (surgery and radiotherapy, except for specific indications) has no benefit for overall survival. Until now tumour stage and the general condition of the patient are the most relevant prognostic factors. Characterising the tumour molecularly and immunologically may lead to a more personalised and effective approach. At the moment, after an exact staging and functional evaluation, an interdisciplinary discussion amongst the tumour board is warranted and offers the best management strategy.

EGFR mutant locally advanced non-small cell lung cancer is at increased risk of brain metastasis

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Locally advanced EGFR+ NSCLC patients have a high likelihood of brain metastasis.

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The high likelihood of EGFR+ brain metastasis is independent of survival duration.

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Surveillance MRI may allow early identification and treatment of brain metastasis.

Background and purpose

Small studies of primarily metastatic non-small cell lung cancer (NSCLC) have suggested an association between EGFR mutation (EGFR+) and likelihood of brain metastasis. However, these studies are confounded by follow-up time bias. We performed a competing risk analysis of brain metastasis in a more uniform locally advanced NSCLC (LA-NSCLC) cohort with known tumor genotype.

Materials and methods

Between 2002 and 2014, 255 patients with LA-NSCLC underwent tumor genotyping for EGFR, ALK and/or KRAS (180 patients had follow-up brain imaging). Cumulative incidence and Fine-Gray regression were performed on clinical variables including genotype and risk of brain metastasis, with death as a competing event.

Results

The proportion of tumors with aberrations in EGFR, ALK and KRAS were 17%, 4% and 28%, respectively. The median follow-up was 68 months. On multivariate analysis, EGFR+ was significantly associated with risk of brain metastasis in the full patient cohort (HR 2.04, 95% CI 1.22–3.39, p = 0.006) as well as in the subset of patients with brain follow-up imaging (HR 1.91. 95% CI 1.17–3.13, p = 0.01). This translated to a higher cumulative incidence of brain metastasis in EGFR+ patients at 3 and 5 years (33.3% vs. 23.2 and 43.8% vs. 24.2%, p = 0.006).

Conclusion

Patients with EGFR+ LA-NSCLC have a significantly higher likelihood of developing brain metastasis after standard combined modality therapy, independent of their longer overall survival. This high-risk genotypic subgroup may benefit from routine surveillance with brain MRI to allow early salvage with targeted systemic- and/or radiation-therapies.

Association of Twice-Daily Radiotherapy With Subsequent Brain Metastases in Adults With Small Cell Lung Cancer

IMPORTANCE

Although thoracic twice-daily radiotherapy (TDRT) is one of the standards of care for small cell lung cancer, its association with brain metastases remains unknown.

OBJECTIVE

To investigate the association of TDRT vs once-daily radiotherapy (ODRT) with brain metastases after prophylactic cranial irradiation in patients with small cell lung cancer.

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter cohort study, data on 778 consecutive patients with small cell lung cancer who had undergone thoracic radiotherapy (609 received ODRT and 169 received TDRT), chemotherapy, and prophylactic cranial irradiation were retrieved from the databases of 8 hospitals in China between July 1, 2003, and June 30, 2016. A 1:1 propensity score matching approach was used to control for confounding between the ODRT and TDRT groups. Confounding covariates included 8 demographic variables and 8 treatment-related covariates. Data analysis was conducted from November 1, 2017, to May 31, 2018, and reanalyzed for revision.

EXPOSURES

The ODRT group received 50 to 66 Gy given in 25 to 33 fractions. The TDRT group received 45 Gy given in 30 fractions.

MAIN OUTCOMES AND MEASURES

The primary end point was brain metastases. Secondary end points included progression-free survival and overall survival.

RESULTS

Of the 778 patients (median age, 55 years [interquartile range, 48-61 years]), 204 were women and 574 were men. At a median follow-up of 23.6 months (interquartile range, 14.2-38.2 months), 131 patients (16.8%) experienced brain metastases. The rate of brain metastasis at 3 years in the TDRT group was significantly higher than in the ODRT group (26.0% vs 16.9%; hazard ratio, 1.55; 95% CI, 1.06-2.26; P = .03). Of the 338 matched patients (169 in the ODRT group vs 169 in the TDRT group), 60 (17.8%) experienced brain metastases, with a rate at 3 years of 14.9% in the ODRT group vs 26.0% in the TDRT group (hazard ratio, 1.71; 95% CI, 1.02-2.88; P = .04). Progression-free survival was similar in both the whole cohort and the matched cohort. Median overall survival in the ODRT group tended to be significantly longer than in the TDRT group after matching (47.2 vs 32.8 months; hazard ratio, 1.41; 95% CI, 0.99-2.01; P = .06).

CONCLUSIONS AND RELEVANCE

In this study, patients with small cell lung cancer who received thoracic TDRT appeared to have a higher risk of brain metastases than those who received ODRT, which supports the need for further prospective randomized clinical trials, especially in China and other parts of Asia.

Lifetime Occurrence of Brain Metastases Arising from Lung, Breast, and Skin Cancers in the Elderly: A SEER-Medicare Study

BACKGROUND

The Surveillance, Epidemiology, and End Results (SEER) Program recently released data on brain metastases (BM) diagnosed during primary cancer staging workup ("synchronous" BM, or SBM); this study examines the incidence of SBM compared with that of lifetime BM (LBM) identified using Medicare claims for patients diagnosed with lung cancer, breast cancer, or melanoma.

METHODS

Incidence proportions (IP) and age-adjusted rates for each of SEER SBM and Medicare LBM are presented along with measures of concordance between the two sources of data, where Medicare LBM were defined by several combinations of diagnosis and putative diagnostic imaging procedure codes.

RESULTS

The SBM IP in lung, breast, and melanoma cancers were 9.6%, 0.3%, and 1.1%, respectively; the corresponding LBM IP were 13.5%, 1.8%, and 3.6%. The greatest SBM IP among patients with lung cancer was 13.4% for non-small cell lung cancer, and among patients with breast cancer was 0.7% for triple-negative breast cancer. The greatest LBM IP among lung cancers was 23.1% in small-cell lung cancer, and among breast cancers was 4.2% for cases of the triple negative subtype.

CONCLUSIONS

Using a large dataset that is representative of the elderly population in the United States, these analyses estimate synchronous and lifetime incidence of BM in lung cancers, breast cancers, and melanomas.

IMPACT

These and other population-based estimates may be used to guide development of BM screening policy and evaluation of real-world data sources.

Phosphorylated-Akt overexpression is associated with a higher risk of brain metastasis in patients with non-small cell lung cancer

Brain metastasis (BM) of non-small cell lung cancer (NSCLC) is relatively common and has a poor prognosis. Moreover, identifying which patients are more likely to develop BM is challenging. Akt, a serine/threonine-specific protein kinase, can be activated in various tumors, including lung cancer, and may be associated with poor prognosis. Here, we used immunohistochemistry to evaluate phosphorylated-Akt (p-Akt) expression in tumor tissues of 99 NSCLC patients. We also analyzed the genotype of the patients for two single nucleotide polymorphisms (SNPs) of the AKT1 gene, rs2498804 and rs2494732. We found that p-Akt expression differs between NSCLC patients and correlates with the risk of BM. Indeed, patients exhibiting medium to high p-Akt expression had a higher incidence of BM than those exhibiting low to no p-Akt expression (39% vs 16%). Our data also show that patients with the rs2498804 GT/GG and rs2494732 CT/TT variant genotypes were more likely to exhibit higher levels of p-Akt expression than those with the rs2498804 TT and rs2494732 CC variant genotypes (35% vs. 24% and 37% vs. 25%, respectively). Our results suggest that the level of expression of p-Akt, which may be affected by the AKT1 genotype, is correlated with the risk of BM. However, further studies are needed to establish p-Akt as a predictive marker for BM in NSCLC patients.