Multivariate analysis of factors predictive of brain metastases in localised non-small cell lung carcinoma

The application of different machine learning models based on PET/CT images and EGFR in predicting brain metastasis of adenocarcinoma of the lung

OBJECTIVE

To explore the value of six machine learning models based on PET/CT radiomics combined with EGFR in predicting brain metastases of lung adenocarcinoma.

METHODS

Retrospectively collected 204 patients with lung adenocarcinoma who underwent PET/CT examination and EGFR gene detection before treatment from Cancer Hospital Affiliated to Shandong First Medical University in 2020. Using univariate analysis and multivariate logistic regression analysis to find the independent risk factors for brain metastasis. Based on PET/CT imaging combined with EGFR and PET metabolic indexes, established six machine learning models to predict brain metastases of lung adenocarcinoma. Finally, using ten-fold cross-validation to evaluate the predictive effectiveness.

RESULTS

In univariate analysis, patients with N2-3, EGFR mutation-positive, LYM%≤20, and elevated tumor markers(P<0.05) were more likely to develop brain metastases. In multivariate Logistic regression analysis, PET metabolic indices revealed that SUVmax, SUVpeak, Volume, and TLG were risk factors for lung adenocarcinoma brain metastasis(P<0.05). The SVM model was the most efficient predictor of brain metastasis with an AUC of 0.82 (PET/CT group),0.70 (CT group),0.76 (PET group).

CONCLUSIONS

Radiomics combined with EGFR machine learning model as a new method have higher accuracy than EGFR mutation alone. SVM model is the most effective method for predicting brain metastases of lung adenocarcinoma, and the prediction efficiency of PET/CT group is better than PET group and CT group.

Computational markers for personalized prediction of outcomes in non-small cell lung cancer patients with brain metastases

Intracranial progression after curative treatment of early-stage non-small cell lung cancer (NSCLC) occurs from 10 to 50% and is difficult to manage, given the heterogeneity of clinical presentations and the variability of treatments available. The objective of this study was to develop a mechanistic model of intracranial progression to predict survival following a first brain metastasis (BM) event occurring at a time [Formula: see text]. Data included early-stage NSCLC patients treated with a curative intent who had a BM as the first and single relapse site (N = 31). We propose a mechanistic mathematical model able to derive computational markers from primary tumor and BM data at [Formula: see text] and estimate the amount and sizes of (visible and invisible) BMs, as well as their future behavior. These two key computational markers are [Formula: see text], the proliferation rate of a single tumor cell; and [Formula: see text], the per day, per cell, probability to metastasize. The predictive value of these individual computational biomarkers was evaluated. The model was able to correctly describe the number and size of metastases at [Formula: see text] for 20 patients. Parameters [Formula: see text] and [Formula: see text] were significantly associated with overall survival (OS) (HR 1.65 (1.07-2.53) p = 0.0029 and HR 1.95 (1.31-2.91) p = 0.0109, respectively). Adding the computational markers to the clinical ones significantly improved the predictive value of OS (c-index increased from 0.585 (95% CI 0.569-0.602) to 0.713 (95% CI 0.700-0.726), p < 0.0001). We demonstrated that our model was applicable to brain oligoprogressive patients in NSCLC and that the resulting computational markers had predictive potential. This may help lung cancer physicians to guide and personalize the management of NSCLC patients with intracranial oligoprogression.

The Impact of Time Interval on Prognosis in Patients with Non-Small Cell Lung Cancer Brain Metastases After Metastases Surgery

BACKGROUND

Non-small cell lung cancer (NSCLC) is a prominent malignancy often linked to the development of brain metastases (BM), which commonly appear at diverse time intervals (TI) following the lung cancer diagnosis. This study endeavors to determine the prognostic significance of the time interval in patients with NSCLC who undergo BM surgery. Through this investigation, we aim to improve our understanding of the factors impacting the prognosis of BM cases originating from NSCLC.

METHODS

We analyzed data from 74 patients (2011-2021) who underwent BM surgery at our institution. The relationship between various clinical, radiological, and histopathological factors, as well as TI and overall survival (OS), was examined.

RESULTS

The median TI from initial NSCLC diagnosis to BM surgery was 19 months (range: 9-36 months). Notably, a shorter TI of less than 23 months was found to be independently associated with postoperative survival (adjusted odds ratio [aOR] 2.87, 95% confidence interval [CI] 1.03-8.02, P = 0.045). Additionally, a shorter TI was independently correlated with the absence of adjuvant chemotherapy for NSCLC (aOR 0.25, 95% CI 0.07-0.83, P = 0.023) and lack of targeted therapy (aOR 0.02, 95% CI 0.00-0.16, P < 0.001). Late-onset BM (TI ≥ 36 months) was observed in 15 cases (20.3%), in this subgroup, patients aged 60 years or older at the time of lung cancer diagnosis exhibited a significant independent correlation with late-onset BM (aOR 7.24, 95% CI 1.59-32.95, P = 0.011). NSCLC patients who underwent adjuvant chemotherapy displayed a notable correlation with late-onset BM (aOR 6.46, 95% CI 1.52-27.43, P = 0.011), while those who received targeted therapy also exhibited an independent association (aOR 2.27, 95% CI 1.70-3.03, P < 0.001).

CONCLUSIONS

Multiple factors contribute to the variability in the onset interval of BM subsequent to NSCLC diagnosis. The occurrence of BM within TI < 23 months following the initial diagnosis of NSCLC was demonstrated as an independent factor associated with an unfavorable prognosis following BM surgery. Furthermore, patients with NSCLC who did not receive adjuvant chemotherapy and lacked targeted therapy were shown to have an elevated likelihood of developing BM after a long progression-free survival.

Osimertinib early dose reduction as a risk to brain metastasis control in EGFR-mutant non-small cell lung cancer

BACKGROUND

The epidermal growth factor receptor (EGFR) mutation is a risk factor associated with brain metastases (BMs) in patients with non-small cell lung cancer (NSCLC). This study aimed to evaluate the impact of osimertinib early dose reduction on BM worsening.

METHODS

We retrospectively analyzed EGFR-mutant NSCLC patients treated with osimertinib as first-line treatment between August 2018 and October 2021. To evaluate the impact of osimertinib early dose reduction, we performed a landmark analysis of patients who achieved disease control at 4 months. Patients were divided into two groups according to whether the osimertinib dose was reduced or not, within 4 months after the start of treatment. We evaluated the time to BMs onset or progression, progression-free survival, and overall survival.

RESULTS

In total, 62 NSCLC patients with EGFR mutations were analyzed. Thirteen patients experienced early dose reduction of osimertinib treatment. Seven patients received osimertinib 40 mg daily, and six received 80 mg every other day. The most common reason for dose reduction was gastrointestinal toxicity (n = 4), followed by skin rashes (n = 3). The time to BMs onset or progression was significantly shorter in patients who experienced early dose reduction than in those who continued regular treatment (Hazard ratio 4.47, 95% confidence interval, 1.52-13.11). The 1-year cumulative incidence of BM onset or progression was 23.1% in the reduced-dose group and 5.0% in the standard dose group. The risk of worsening BMs with early dose reduction of osimertinib treatment was higher in patients who had BMs before treatment and in younger patients.

CONCLUSION

Early dose reduction of osimertinib was a risk factor for the worsening of BMs. A higher risk was associated with younger patients and those presenting BMs before treatment.

Leptomeningeal Metastases in Melanoma Patients: An Update on and Future Perspectives for Diagnosis and Treatment

Leptomeningeal disease (LMD) is a devastating complication of cancer with a particularly poor prognosis. Among solid tumours, malignant melanoma (MM) has one of the highest rates of metastasis to the leptomeninges, with approximately 10-15% of patients with advanced disease developing LMD. Tumour cells that metastasise to the brain have unique properties that allow them to cross the blood-brain barrier, evade the immune system, and survive in the brain microenvironment. Metastatic colonisation is achieved through dynamic communication between metastatic cells and the tumour microenvironment, resulting in a tumour-permissive milieu. Despite advances in treatment options, the incidence of LMD appears to be increasing and current treatment modalities have a limited impact on survival. This review provides an overview of the biology of LMD, diagnosis and current treatment approaches for MM patients with LMD, and an overview of ongoing clinical trials. Despite the still limited efficacy of current therapies, there is hope that emerging treatments will improve the outcomes for patients with LMD.

Risk factors and a new nomogram for predicting brain metastasis from lung cancer: a retrospective study

Objective

This study aims to establish and validate a new nomogram for predicting brain metastasis from lung cancer by integrating data.

Methods

266 patients diagnosed as lung cancer between 2016 and 2018 were collected from Guangdong Academy of Medical Sciences. The first 70% of patients were designated as the primary cohort and the remaining patients were identified as the internal validation cohort. Univariate and multivariable logistics regression were applied to analyze the risk factors. Independent risk factors were used to construct nomogram. C-index was used to evaluate the prediction effect of nomogram.100 patients diagnosed as lung cancer between 2018 and 2019 were collected for external validation cohorts. The evaluation of nomogram was carried out through the distinction and calibration in the internal validation cohort and external validation cohort.

Results

166 patients were diagnosed with brain metastasis among the 266 patients. The gender, pathological type (PAT), leukocyte count (LCC) and Fibrinogen stage (FibS) were independent risk factors of brain metastasis. A novel nomogram has been developed in this study showed an effective discriminative ability to predict the probability of lung cancer patients with brain metastasis, the C-index was 0.811.

Conclusion

Our research provides a novel model that can be used for predicting brain metastasis of lung cancer patients, thus providing more credible evidence for clinical decision-making.

Factors Affecting 2-Year Survival in Patients With Non-Small Cell Lung Cancer Brain Metastases: Evidence from Indonesia's National Cancer Center, Jakarta, Indonesia

Background

Brain metastases are a common complication in a wide range of cancers but are ubiquitous among patients with lung cancer. Limited data are available on the survival of patients with lung cancer and brain metastases in Indonesia. In this study, we aimed to identify the factors that might contribute to and predict survival in patients with non-small cell lung cancer (NSCLC) that resulted in brain metastases.

Methods

This retrospective study on patients with NSCLC and brain metastases was conducted using data available from the medical records of the Dharmais National Cancer Hospital, Jakarta, Indonesia. The study outcome was survival time, which was associated with sex, age, smoking status, body mass index, number of brain metastases, tumor location, systemic therapy, and other therapies. Descriptive statistics, median survival, Kaplan-Meier graphs, and Cox regression were analyzed using SPSS version 27.

Results

We included 111 patients with NSCLC and brain metastases in this study. The median patient age was 58 years. Long survivorship was observed among women (median: 95.4 weeks; P < .0003), patients with epidermal growth factor receptor (EGFR) mutations (median: 41.8 weeks; P < .0492), those who received chemotherapy (median: 58 weeks; P < .000), and those who received a combination of surgery and whole brain radiotherapy (WBRT; median: 64.7 weeks; P = .0174). Multivariate analysis showed consistent results for the following factors: sex, EGFR mutations, systemic therapy, and surgery plus WBRT.

Conclusions

Female sex and EGFR mutations in patients with NSCLC and brain metastases are associated with a high survival rate. Patients who have NSCLC with brain metastases will benefit from treatment with EGFR tyrosine kinase inhibitors, chemotherapy, and surgery plus WBRT.

Upfront and Repeated Stereotactic Radiosurgery in Patients With Brain Metastases From NSCLC

INTRODUCTION

Approximately 40% of non-small-cell lung cancer (NSCLC) patients develop brain metastases (BM). Stereotactic radiosurgery (SRS) instead of whole-brain radiotherapy (WBRT) is increasingly administered as an upfront treatment to patients with a limited number of BM. We present outcomes and validation of prognostic scores for these patients treated with upfront SRS.

METHODS

We retrospectively analyzed 199 patients with a total of 268 SRS courses for 539 brain metastases. Median patient age was 63 years. For larger BM, dose reduction to 18 Gy or hypofractionated SRS in 6 fractions was applied. We analyzed the BMV-, the RPA-, the GPA- and the lung-mol GPA score. Cox proportional hazards models with univariate and multivariate analyses were fitted for overall survival (OS) and intracranial progression-free survival (icPFS).

RESULTS

Sixty-four patients died, 7 of them of neurological causes. Thirty eight patients (19,3%) required a salvage WBRT. Median OS was 38, 8 months (IQR: 6-NA). In univariate analysis as well as multivariate analysis, the Karnofsky performance scale index (KPI) ≥90% (P = 0, 012 and P = 0, 041) remained as independent prognostic factor for longer OS. All 4 prognostic scoring indices could be validated for OS assessment (BMV P = 0, 007; RPA P = 0, 026; GPA P = 0, 003; lung-mol GPA P = 0, 05).

CONCLUSION

In this large cohort of NSCLC patients with BM treated with upfront and repeated SRS, OS was markedly favourable, in comparison to literature. Upfront SRS is an effective treatment approach in those patients and can decidedly reduce the impact of BM on overall prognosis. Furthermore, the analysed scores are useful prognostic tools for OS prediction.

The surgical resection of the primary tumor increases survival in patients with EGFR-mutant advanced non-small cell lung cancer: a tertiary center cohort study

Tumor resection could increase treatment efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKI) in patients with advanced EGFR-mutant non-small cell lung cancer (NSCLC). This study aimed to retrospectively analyze patients with advanced EGFR-mutant NSCLC from a Taiwanese tertiary center and receiving EGFR-TKI treatment with or without tumor resection. A total of 349 patients were enrolled. After propensity score matching, 53 EGFR-TKI treated patients and 53 EGFR-TKI treated patients with tumor resection were analyzed. The tumor resection group showed improved progression-free survival (PFS) (52.0 vs. 9.8 months; hazard ratio [HR] = 0.19; p < 0.001) and overall survival (OS) (not reached vs. 30.6 months; HR = 0.14; p < 0.001) compared to the monotherapy group. In the subgroup analysis of patients with newly-diagnosed NSCLC, the tumor resection group showed longer PFS (52.0 vs. 9.9 months; HR = 0.14; p < 0.001) and OS (not reached vs. 32.6 months; HR = 0.12; p < 0.001) than the monotherapy group. In conclusion. the combination of EGFR-TKI and tumor resection provided better PFS and OS than EGFR-TKI alone, and patients who underwent tumor resection within six months had fewer co-existing genomic alterations and better PFS.

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.

Identification of nine mutant genes and establishment of three prediction models of organ tropism metastases of non-small cell lung cancer

BACKGROUND

Most Non-small cell lung cancer (NSCLC) patients tend to have metastases at the initial diagnosis. However, limited knowledge has been established regarding which factors, are associated with its metastases. This study aims to identify more biomarkers associated with its organ tropism metastasis and to establish models for prediction of its metastatic organs.

METHODS

We performed targeted next-generation sequencing (NGS) to detect genes related to lung cancer in 272 patients with primary advanced NSCLC from Northeast China. We adopted Fisher test, multivariate logistic regression analysis to identify metastasis-related gene mutations and to establish prediction models.

RESULTS

Mutations of EGFR (p = 0.0003, OR = 2.554) (especially EGFR L858R [p = 0.02, OR = 2.009]), ATM (p = 0.008, OR = 11.032), and JAK2 (p = 0.009, OR = Inf) were positively and of TP53 exon4mut (p = 0.001, OR = 0.173) was negatively correlated with lung metastasis, and those of CSF1R (p = 0.01, OR = Inf), KIT (p = 0.03, OR = 4.746), MYC (p = 0.05, OR = 7.938), and ERBB2 (p = 0.02, OR = 2.666) were positively correlated with pleural dissemination; those of TP53 (p = 0.01, OR = 0.417) was negatively, while of SMAD4 (p = 0.03, OR = 4.957) was positively correlated with brain metastasis of NSCLC. Additionally, smoking history (p = 0.004, OR = 0.004) was negatively correlated with pleural dissemination of NSCLC. Furthermore, models for prediction of lung metastasis (AUC = 0.706), pleural dissemination (AUC = 0.651), and brane metastasis (AUC = 0.629) were established.

CONCLUSION

Taken together, this study revealed nine mutant genes and smoking history associated with organ tropism metastases of NSCLC and provided three models for the prediction of metastatic organs. This study enables us to predict the organs to which non-small cell lung cancer metastasizes before it does develop.

Hippocampal Metastasis Rate Based on Non-Small Lung Cancer TNM Stage and Molecular Markers

Hippocampal-avoidance whole-brain radiation therapy (HA-WBRT) is justified because of low hippocampal brain metastases (BM) rate and its prevention of cognitive decline. However, we hypothesize that the risk of developing BM in the hippocampal-avoidance region (HAR) may differ depending on the lung-cancer stage and molecular status. We retrospectively reviewed 123 patients with non-small cell lung cancer (NSCLC) at the initial diagnosis of BM. The number of BMs within the HAR (5 mm expansion) was counted. The cohort was divided into patients with and without BMs in the HAR, and their clinical variables, TNM stage, and epidermal growth factor receptor (EGFR) status were compared. The most influential variable predicting BMs in the HAR was determined using multi-variable logistic regression, classification and regression tree (CART) analyses, and gradient boosting method (GBM). The feasibility of HAR expansion was tested using generalized estimating equation marginal model. Patients with BMs in the HAR were more frequently non-smokers, and more likely to have extra-cranial metastases and EGFR mutations (p<0.05). Multi-variable analysis revealed that extra-cranial metastases were independently associated with the presence of BM in the HAR (odds ratio=8.75, p=0.04). CART analysis and GBM revealed that the existence of extra-cranial metastasis was the most influential variable predicting BM occurrence in the HAR (variable importance: 23% and relative influence: 37.38). The estmated BM incidence of patients without extra-cranial metastases in th extended HAR (7.5-mm and 10-mm expansion) did not differ significantly from that in the conventional HAR. In conclusion, NSCLC patients with extra-cranial metastases were more likely to have BMs in the HAR than those without extra-cranial metastases.

What Factors Are Associated With Local Metastatic Lesion Progression After Intramedullary Nail Stabilization?

BACKGROUND

Pathologic fracture of the long bones is a common complication of bone metastases. Intramedullary nail stabilization can be used prophylactically (for impending fractures) or therapeutically (for completed fractures) to preserve mobility and quality of life. However, local disease progression may occur after such treatment, and there is concern that surgical instrumentation and the intramedullary nail itself may seed tumor cells along the intramedullary tract, ultimately leading to loss of structural integrity of the construct. Identifying factors associated with local disease progression after intramedullary nail stabilization would help surgeons predict which patients may benefit from alternative surgical strategies.

QUESTIONS/PURPOSES

(1) Among patients who underwent intramedullary nail stabilization for impending or completed pathologic fractures of the long bones, what is the risk of local progression, including progression of the existing lesion and development of a new lesion around the nail? (2) Among patients who experience local progression, what proportion undergo reoperation? (3) What patient characteristics and treatment factors are associated with postoperative local progression? (4) What is the difference in survival rates between patients who experienced local progression and those with stable local disease?

METHODS

Between January 2013 and December 2019, 177 patients at our institution were treated with an intramedullary nail for an impending or completed pathologic fracture. We excluded patients who did not have a pathologic diagnosis of metastasis before fixation, who were younger than 18 years of age, who presented with a primary soft tissue mass that eroded into bone, and who experienced nonunion from radiation osteitis or an avulsion fracture rather than from metastasis. Overall, 122 patients met the criteria for our study. Three fellowship-trained orthopaedic oncology surgeons involved in the care of these patients treated an impending or pathologic fracture with an intramedullary nail when a long bone lesion either fractured or was deemed to be of at least 35% risk of fracture within 3 months, and in patients with an anticipated duration of overall survival of at least 6 weeks (fractured) or 3 months (impending) to yield palliative benefit during their lifetime. The most common primary malignancy was multiple myeloma (25% [31 of 122]), followed by lung carcinoma (16% [20 of 122]), breast carcinoma (15% [18 of 122]), and renal cell carcinoma (12% [15 of 122]). The most commonly involved bone was the femur (68% [83 of 122]), followed by the humerus (27% [33 of 122]) and the tibia (5% [6 of 122]). A competing risk analysis was used to determine the risk of progression in our patients at 1 month, 3 months, 6 months, and 12 months after surgery. A proportion of patients who ultimately underwent reoperation due to progression was calculated. A univariate analysis was performed to determine whether lesion progression was associated with various factors, including the age and sex of the patient, use of adjuvant therapies (radiation therapy at the site of the lesion, systemic therapy, and antiresorptive therapy), histologic tumor type, location of the lesion, and fracture type (impending or complete). Patient survival was assessed with a Kaplan-Meier curve. A p value < 0.05 was considered significant.

RESULTS

The cumulative incidence of local tumor progression (with death as a competing risk) at 1 month, 3 months, 6 months, and 12 months after surgery was 1.9% (95% confidence interval 0.3% to 6.1%), 2.9% (95% CI 0.8% to 7.5%), 3.9% (95% CI 1.3% to 8.9%), and 4.9% (95% CI 1.8% to 10.3%), respectively. Of 122 patients, 6% (7) had disease progression around the intramedullary nail and 0.8% (1) had new lesions at the end of the intramedullary nail. Two percent (3 of 122) of patients ultimately underwent reoperation because of local progression. The only factors associated with progression were a primary tumor of renal cell carcinoma (odds ratio 5.1 [95% CI 0.69 to 29]; p = 0.03) and patient age (difference in mean age 7.7 years [95% CI 1.2 to 14]; p = 0.02). We found no associations between local disease progression and the presence of visceral metastases, other skeletal metastases, radiation therapy, systemic therapy, use of bisphosphonate or receptor activator of nuclear factor kappa-B ligand inhibitor, type of fracture, or the direction of nail insertion. There was no difference in survivorship curves between those with disease progression and those with stable local disease (= 0.36; p = 0.54).

CONCLUSION

Our analysis suggests that for this population of patients with metastatic bone disease who have a fracture or impeding fracture and an anticipated survival of at least 6 weeks (completed fracture) or 3 months (impending fracture), the risk of experiencing local progression of tumor growth and reoperations after intramedullary nail stabilization seems to be low. Lesion progression was not associated with the duration of survival, although this conclusion is limited by the small number of patients in the current study and the competing risks of survival and local progression. Based on our data, patients who present with renal cell carcinoma should be cautioned against undergoing intramedullary nailing because of the risk of postoperative lesion progression.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Pretreatment Thoracic CT Radiomic Features to Predict Brain Metastases in Patients With ALK-Rearranged Non-Small Cell Lung Cancer

Objective: To identify CT imaging biomarkers based on radiomic features for predicting brain metastases (BM) in patients with ALK-rearranged non-small cell lung cancer (NSCLC).

Methods: NSCLC patients with pathologically confirmed ALK rearrangement from January 2014 to December 2020 in our hospital were enrolled retrospectively in this study. Finally, 77 patients were included according to the inclusion and exclusion criteria. Patients were divided into two groups: BM+ were those patients who were diagnosed with BM at baseline examination (n = 16) or within 1 year’s follow-up (n = 14), and BM− were those without BM followed up for at least 1 year (n = 47). Radiomic features were extracted from the pretreatment thoracic CT images. Sequential univariate logistic regression, LASSO regression, and backward stepwise logistic regression were used to select radiomic features and develop a BM-predicting model.

Results: Five robust radiomic features were found to be independent predictors of BM. AUC for radiomics model was 0.828 (95% CI: 0.736–0.921), and when combined with clinical features, the AUC was increased (p = 0.017) to 0.909 (95% CI: 0.845–0.972). The individualized BM-predicting model incorporated with clinical features was visualized by the nomogram.

Conclusion: Radiomic features extracted from pretreatment thoracic CT images have the potential to predict BM within 1 year after detection of the primary tumor in patients with ALK-rearranged NSCLC. The radiomics model incorporated with clinical features shows improved risk stratification for such patients.

Bevacizumab's association with a decreased risk of brain metastases in ECOG-ACRIN E1505, a phase III randomized trial of adjuvant chemotherapy with or without bevacizumab in surgically-resected NSCLC

Introduction

ECOG-ACRIN E1505 was a phase 3 randomized trial of adjuvant chemotherapy with or without bevacizumab for patients with stages IB (>4 cm) to IIIA NSCLC. We sought to estimate the incidence and risk factors for brain recurrence as compared with extracranial recurrences (ECRs).

Methods

ECOG-ACRIN E1505 noted that bevacizumab failed to improve overall survival (OS) (OS hazard ratio [HR] = 0.99 [0·82–1·19], p = 0.90) or recurrence-free survival when added to chemotherapy in the adjuvant setting. The cumulative incidence of brain/ECR was estimated after adjusting for recurrence at other sites and death as competing events. A multivariable regression model was fitted using competing risk analysis to evaluate the effect of covariates on brain recurrence incidence.

Results

Median follow-up was 50.4 months. Among the 1501 patients enrolled, 472 developed ECR. There were 122 patients who had recurrence in the brain with or without simultaneous ECR as the first recurrence site (all-brain recurrences [ABRs]), and 84 of those with ABRs had recurrence in the brain only (isolated-brain recurrence [IBR]). The incidence of ABR, IBR, and ECR at 6 years was 9.9%, 5.9%, and 38.8%, respectively. Chemotherapy plus bevacizumab was associated with a decreased incidence of ABR (HR = 0.64, p = 0.02) and IBR (HR = 0.62, p = 0.032), but there was no significant trend for an OS decrement in the bevacizumab arm versus the control arm for both ABR and IBR. Median survivals associated with IBR, ABR, and ECR were 9.5, 9.5, and 14.1 months, respectively. Nonsquamous histology (HR = 1.87, p = 0.003) was also associated with ABR. ECR was associated with nonsquamous NSCLC histology (HR = 1.79, p < 0.01) and stage/N2 involvement (HR = 1.13/1.37, both p < 0.01).

Conclusions

The addition of bevacizumab to chemotherapy was associated with reduction in brain recurrences, but not ECR. Brain metastases whether isolated or not are associated with a lower median survival than ECR and unlike ECR are not associated with traditional staging variables.

Predictive Indicators of Brain Metastasis-Free Survival in Patients With Lung Cancer at a Chinese Cancer Center

Introduction

Metastasis tumors of the brain derive mostly from lung cancer, breast cancer, melanoma, and more commonly among lung cancer patients. Once brain metastasis is diagnosed, the prognosis of untreated patients is shown to be very poor. In this study, we describe the clinical and pathological features of patients with lung cancer at our institution from 2009 to 2021. We also examined factors like gender, type, size, and location of the primary tumor and leukoaraiosis level at the first visit are associated with patients’ brain metastasis-free survival (the time free of brain metastases since the first diagnosis of lung cancer).

Materials and methods

We retrospectively reviewed patients with a final histologic diagnosis of lung cancer from September 2009 to January 2015. The evaluation included history, physical examination, and contrast-enhanced computerized tomography of the chest. Contrast-enhanced magnetic resonance imaging of the head was performed at the first visit and following treatment. The patients’ age, gender, tumor size, histology type, location of the lung tumor, and leukoaraiosis level at the first visit were recorded and correlated to the patients’ brain-metastasis-free survival time.

Results

The study included 68 patients - 39 males and 29 females -with a mean age of 55.15 years (range 35-69 years). Adenocarcinoma was diagnosed in 47 patients (22 males and 25 females), Squamous carcinoma was diagnosed in 12 patients (9 males and 3 females), non-small cell lung carcinoma was diagnosed in 3 patients (2 males and one female), one male patient had the diagnosis of adenosquamous tumor and 1 male patient had the diagnosis of neuroendocrine tumor. Tumor size was <3 cm in 19 patients, 3-5 cm in 29 patients, 5-10 cm in 17 patients, and three other patients’ size was hard to measure. Of the 68 patients, 10 patients were detected as brain metastasis by magnetic resonance imaging at first diagnosis, 22 patients were diagnosed as brain metastasis during the follow-up visits, 36 patients were not found as brain metastasis until the last visit. According to the Cox regression univariate analysis, two factors were correlated to shorter brain metastasis-free survival: Not-squamous lung carcinoma (SCC) and higher location of the tumor. The multivariate statistical analysis correlated two factors to shorter brain metastasis-free survival: non-SCC histology type and age≥62.

Conclusions

In conclusion, we found that SCC had a lower incidence of brain metastasis in patients than other lung cancer types. According to the Cox regression multivariate analysis, age <62 and SCC were two protective factors of brain metastasis. According to the Cox regression univariate and analysis. The lower location of the tumor was the protective factor of brain metastasis. According to the Cox regression univariate analysis, other parameters, such as gender or tumor size, did not have a role in brain metastasis-free survival in these patients.

Benchmarking prognosis methods for survivability - A case study for patients with contingent primary cancers

BACKGROUND

There is an increasing number of patients with a first primary cancer who are diagnosed with a second primary cancer, but prognosis methods to predict the survivability of a patient with multiple primary cancers have not been fully benchmarked.

METHODS

This study investigated the five-year survivability prognosis performances of six machine learning approaches. These approaches are: artificial neural network, decision tree (DT), logistic regression, support vector machine, naïve Bayes (NB), and Bayesian network (BN). A synthetic minority over-sampling technique (SMOTE) was used to solve the imbalanced problem, and a nationwide cancer patient database containing 7,845 subjects in Taiwan was used as a sample source. Ten primary and secondary cancers and their key variables affecting the survivability of the patients were identified.

RESULTS

All the models using SMOTE improved sensitivity and specificity significantly. NB has the highest performance in terms of accuracy and specificity, whereas BN has the highest performance in terms of sensitivity. Further, the computational time and the power of knowledge representation of NB, BN, and DT outperformed the others.

CONCLUSIONS

Selecting the appropriate prognosis models to predict survivability of patients with two contingent primary cancers can aid precise prediction and can support appropriate treatment advice.

Identification of predictors for brain metastasis in newly diagnosed non-small cell lung cancer: a single-center cohort study

OBJECTIVES

To identify clinical and staging chest CT characteristics predictive of brain metastasis in patients with newly diagnosed NSCLC dichotomized according to resectability.

METHODS

Patients newly diagnosed with NSCLC of clinical stages II-IV between November 2017 and October 2018 were enrolled and classified into resectable (stage II+IIIA) and unresectable stages (stage IIIB/C+IV) according to chest CT. Associations of clinicopathological characteristics and CT findings with brain metastasis were analyzed using logistic regression. Predictive models were evaluated using receiver operating characteristics curve analysis. A subgroup analysis for unresectable-stage patients with known epidermal growth factor receptor gene (EGFR) mutation status was performed.

RESULTS

This study included 911 NSCLC patients (mean age, 65 ± 11 years; 620 men), 194 of whom were diagnosed with brain metastasis. For resectable stages, independent predictors for brain metastasis were N2-stage (13 of 25 patients), absence of air-bronchogram/bubble lucency (23 of 25 patients), and presence of spiculation (15 of 25 patients), with a model combining the two imaging features showing an AUC of 0.723. In unresectable stages, independent predictors of brain metastasis were younger age, female sex, extrathoracic metastasis, and adenocarcinoma, with models combining these showing AUCs of 0.675-0.766. In the subgroup with known EGFR-mutation status, extrathoracic metastasis and positive EGFR mutation were independent predictors of brain metastasis, with the model showing AUCs of 0.641-0.732.

CONCLUSION

CT-derived imaging features, clinical stages, lung cancer subtype, and EGFR mutation were associated with brain metastasis in patients with newly diagnosed NSCLC. The predictors were completely different between resectable and unresectable stages.

KEY POINTS

• In resectable stages of NSCLC, two imaging features (absence of air-bronchogram/bubble lucency and presence of spiculation) and N2 stage were independent predictors of brain metastasis. • In unresectable stages of NSCLC, younger age, female sex, extrathoracic metastasis, and adenocarcinoma were associated with brain metastasis. • In the subgroup of NSCLC with known EGFR-mutation status, extrathoracic metastasis and positive EGFR mutation were independent predictors of brain metastasis.

Real-world outcomes of first- and second-generation tyrosine kinase inhibitors first-line in patients with epidermal growth factor receptor mutation-positive non-small cell lung cancer: A retrospective observational cohort study

The sequencing of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in patients with EGFR mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC) remains a matter of controversy. This cohort study analyzed the overall survival (OS) and progression-free survival (PFS) of afatinib compared with erlotinib and gefitinib first-line. EGFRm+, advanced NSCLC patients treated with either afatinib, erlotinib or gefitinib were retrospectively analyzed. A total of 107 patients were included. There was no statistically significant difference in PFS among the 3 groups. In the ≥ 60 years age group, the afatinib group had longer survival compared to the gefitinib group (p = 0.01). Median OS were 19.1, 22.9, and 35.6 months for gefitinib, erlotinib, and afatinib groups, respectively, with statistical significance between the gefitinib and afatinib groups (p = 0.009). Patients on afatinib also had longer median OS than erlotinib and gefitinib pooled together (35.5 versus 21.4 months; hazard ratio = 0.54, p = 0.016), despite similar median PFS. In conclusion, afatinib is a better choice compared to gefitinib or erlotinib for EGFRm+ patients. The OS obtained with afatinib is just 3 months shorter than osimertinib in the FLAURA trial. Direct comparison studies with osimertinib are still needed to determine optimal sequencing.

Micropapillary Predominance Is a Risk Factor for Brain Metastasis in Resected Lung Adenocarcinoma

BACKGROUND

Histologic subtyping offers some prognostic value in lung adenocarcinoma. We thus hypothesized that histologic subtypes may be useful for risk stratification of brain metastasis (BM). In this study, we aimed to investigate the impact of histologic subtypes on the risk for BM in patients with resected lung adenocarcinoma.

PATIENTS AND METHODS

Of 1099 consecutive patients who had undergone curative-intent surgery (2000-2014), 448 patients who had undergone complete resection for lung adenocarcinoma were included in this study. Correlated clinical variables and BM-free survival were analyzed.

RESULTS

Micropapillary predominance was significantly associated with higher risk of BM after complete resection in univariate analyses (P < .001). In addition, multivariate analyses showed that micropapillary predominance was an independent risk factor for BM (hazard ratio = 2.727; 95% confidence interval, 1.260-5.900; P = .011), along with younger age and advanced pathologic stage. Unlike the other subtypes, an increase in the percentage of the micropapillary subtype was positively correlated with an increase in BM frequency. Patients with micropapillary adenocarcinoma showed significantly poorer brain metastasis-free survival compared with those with non-micropapillary adenocarcinoma (3 years, 78.2% vs. 95.6%; 5 years, 67.3% vs. 94.3%; P < .001).

CONCLUSION

The current study demonstrated a significant correlation between micropapillary subtype and higher risk of BM in patients with resected lung adenocarcinoma. This routine histologic evaluation of resected adenocarcinoma may provide useful information for the clinician when considering postoperative management in patients with lung adenocarcinoma. Histologic subtyping offer some prognostic value in lung adenocarcinoma. Because brain metastasis is critical and often refractory to systemic chemotherapy, early detection is clinically important to achieve effective local treatment. We retrospectively analyzed the association between histologic subtypes and occurrence of brain metastasis and found a significant association between micropapillary predominance and higher risk for brain metastasis. Our findings may be relevant when considering postoperative management.

Risk factors for brain metastases from non-small-cell lung cancer: A protocol for observational study

Brain metastasis is a common site of distant metastasis of non-small-cell lung cancer (NSCLC) that greatly reduces the prognosis of patients. In this study, we explored the correlation between different clinical factors and secondary brain metastases in NSCLC in an attempt to identify NSCLC patient populations at high risk of metastasis to the central nervous system.We collected data for 350 NSCLC patients from the medical record system of the First Affiliated Hospital of Nanchang University from June 2015 to June 2019, and these patients had pathologically verified diagnoses. The correlations between age at the time of diagnosis, sex, histological type, calcium concentration, hemoglobin (HB), fibrinogen (Fbg), activated partial thromboplastin time (APTT), alkaline phosphatase (ALP), carcinoembryonic antigen (CEA), CA125, and CA199 levels and brain metastasis were analyzed. Multivariate logistic regression analysis was used to identify risk factors for NSCLC brain metastasis. A receiver operating characteristic (ROC) curve was used to calculate the cutoff, sensitivity, and specificity of the independent related factors.Of the 350 patients, 57 were diagnosed with brain metastases. Univariate and multivariate logistic regression analysis indicated that lesion diameter, calcium concentration, and CEA level were independent risk factors correlated with brain metastasis (P < .05). There were no significant differences in age, sex, type of histopathology, presence or absence of mediastinal lymph node metastasis, HB, Fbg, APTT, ALP, cancer antigen 125 (CA-125), or cancer antigen 199 (CA-199) levels between patients with brain metastases and patients without brain metastases (P > .05, respectively). ROC curves demonstrated that these factors had comparable accuracy in predicting brain metastasis (area under the curve [AUCs] were 0.620, 0.661, and 0.729, respectively). The cutoff values for lesion diameter, calcium, and CEA were 5.050 cm, 2.295 mmol/L, and 11.160 ng/mL, respectively. The sensitivities for prediction brain metastasis were 59.6%, 64.9%, and 73.3%, with specificities of 63.1%, 59.2%, and 70.3%, respectively.According to our study, lesion diameter, calcium concentration, and CEA level are independent risk factors for brain metastases in NSCLC patients. Thus, we can strengthen the regular follow-up of NSCLC patients with tumor diameter > 5.050 cm, calcium > 2.295 mmol/L, CEA > 11.160 ng/mL, and use these factors as a reference for preventive treatments.

Vimentin expression status is a potential biomarker for brain metastasis development in EGFR-mutant NSCLC patients

Background

Despite advances in systemic therapy and improvements in survival for advanced epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC), brain metastasis (BM) remains a poor outcome. Previous studies on risk factors for BM occurrence included unselected patients and biomarker prediction of BM in these populations were not well studied. We aimed to identify the role of epithelial mesenchymal transition (EMT) marker and clinical factors predicting BM in

EGFR

mutant NSCLC patients.

Methods

Advanced EGFR-mutant NSCLC patients in the King Chulalongkorn Memorial Hospital from January 2013 to December 2017 were included. Vimentin expression was assessed by immunohistochemistry. The correlation between vimentin expression and factors associated with BM occurrence was analyzed by univariate and multivariate analyses.

Results

304 patients were enrolled. Of these, 149 patients (49%) developed BM. In multivariate analysis, the occurrence of BM was associated with age <60 years, metastatic disease at diagnosis, and 3 or more metastatic sites. Moreover, positive vimentin expression was also found more common in patients with BM than those without BM (52.4% vs. 27.6%, respectively) and predicted overall BM development in EGFR-mutant patients (OR 2.53, 95% CI, 1.11–5.77; P=0.027). Overall survival (OS) was shorter in vimentin^positive group than in vimentin^negative group. Median OS was 20.0 months (95% CI, 14.51–25.51) and 30.9 months (95% CI, 20.99–40.84), respectively (HR, 1.57; P=0.04).

Conclusions

Younger patients with EGFR-mutant NSCLC who had high disease burden were more likely to develop BM. Vimentin served as a biomarker for predicting BM and poor prognostic factor in EGFR-mutant patients. EMT pathway may be considered as a therapeutic target in these high-risk populations.

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.

First-line treatment with irreversible tyrosine kinase inhibitors associated with longer OS in EGFR mutation-positive non-small cell lung cancer

Background

Few studies have compared the efficacy of the irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR‐TKI), afatinib, with that of reversible EGFR‐TKIs. Therefore, this study assessed the effectiveness of afatinib, erlotinib, and gefitinib in terms of OS (overall survival) and progression‐free survival (PFS) in EGFR mutation‐positive advanced non‐small cell lung cancer (NSCLC) patients.

Methods

Patients with EGFR mutation‐positive advanced NSCLC who sought treatment from December 2013 to June 2018, at a tertiary referral center were retrospectively analyzed. These patients were treated with afatinib or a reversible EGFR‐TKI (erlotinib or gefitinib) until disease progression, intolerable adverse events, or death. The Kaplan‐Meier and log‐rank tests were then used to compare the OS and PFS of the patients. We further analyzed the survival differences among the subgroup of patients without brain metastases.

Results

Of the 363 patients enrolled, 134 and 229 received first‐line afatinib and first‐line reversible EGFR‐TKI, respectively. Those given afatinib had better OS (39.3 vs. 26.0 months; HR 0.65, P = 0.033) and PFS (14.1 vs.11.2 months; HR 0.58, P < 0.001). Of the 246 patients without brain metastases, 93 and 153 received first‐line afatinib and a first‐line reversible EGFR‐TKI, respectively. Those given afatinib had a better OS (52.6 vs. 24.9 months; HR 0.62, P = 0.0030) and PFS (17.7 vs. 11.1 months; HR 0.51, P < 0.001). The survival benefit was more significant in the subgroup of patients with L858R substitutions.

Conclusions

The results indicated that afatnib resulted in significantly better OS and PFS than gefitnib and erlotinib for EGFR mutation‐positive advanced NSCLC patients without brain metastases.

Key points

Significant findings of the study

Afatnib resulted in significantly better overall survival and progression‐free survival than gefitnib and erlotinib for EGFR mutation‐positive advanced non‐small cell lung cancer patients without brain metastases.

What this study adds

This study helps fill the gap in our limited understanding of the differences in the efficacy of the irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR‐TKI), afatinib, with that of reversible EGFR‐TKIs.

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.

Survivability modelling using Bayesian network for patients with first and secondary primary cancers

BACKGROUND AND OBJECTIVE

Multiple primary cancers significantly threat patient survivability. Predicting the survivability of patients with two cancers is challenging because its stochastic pattern relates with numerous variables.

METHODS

In this study, a Bayesian network (BN) model was proposed to describe the occurrence of two primary cancers and predict the five-year survivability of patients using probabilistic evidence. Eleven types of major primary cancers and contingent occurrences of secondary cancers were investigated. A nationwide two-cancer database involving 7,845 patients in Taiwan was investigated. The BN topology is rigorously examined and imbalanced dataset is processed by the synthetic minority oversampling technique. The proposed BN survivability prognosis model was compared with benchmark approaches.

RESULTS

The proposed model significantly outperformed the back-propagation neural network, logistic regression, support vector machine, and naïve Bayes in terms of sensitivity, which is a critical performance index for the non-survival group.

CONCLUSIONS

Using the proposed BN model, one can estimate the posterior probabilities for every query provided appropriate prior evidences. The potential survivability information of patients, treatment effects, and socio-demographics factor effects predicted by the proposed model can help in cancer treatment assessment and cancer development monitoring.

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 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.

The Role of Prophylactic Cranial Irradiation in Patients With Non-small Cell Lung Cancer: An Updated Systematic Review and Meta-Analysis

Background: The purpose of this study was to reevaluate the efficacy of prophylactic cranial irradiation (PCI) in non-small cell lung cancer (NSCLC) with the most recent published data and to identify subgroups who may be more likely to gain benefit from PCI.

Methods: We searched PubMed, Embase, and Cochrane databases for randomized trials comparing PCI with non-PCI in NSCLC patients. We pooled the data of randomized controlled trials and compared brain metastasis (BM) and overall survival (OS) between PCI group and non-PCI group.

Results: Seven studies including 1,462 patients were eligible for the current meta-analysis. Compared to non-PCI group, PCI group achieved decreased BM (RR = 0.37, 95% CI: 0.26–0.52) but similar OS (HR = 1.01, 95% CI: 0.87–1.22). In subgroup analyses of BM, PCI decreased BM for subgroups by pathology (squamous cell carcinoma or non-squamous cell carcinoma) and local treatment modality (surgery or no surgery). However, PCI failed to reduce BM for patients with poor performance status (WHO 2–3). The incidence of PCI related toxicities was low and PCI was well-tolerated by the majority of NSCLC. Low grade neurocognitive function (NCF) decline was reported in NAVLT study and greater deterioration in immediate and delayed recall was reported in RTOG 0214. No significant difference in quality of life (QOL) after PCI was reported.

Conclusion: PCI reduces the incidence of BM except for patients with poor performance status. However, PCI fails to prolong OS significantly for NSCLC. An individual patient data meta-analysis may identify patients that could achieve OS prolongation with PCI.

CT-Based Radiomics Model for Predicting Brain Metastasis in Category T1 Lung Adenocarcinoma

OBJECTIVE. The purpose of this study is to develop and evaluate an unenhanced CT-based radiomics model to predict brain metastasis (BM) in patients with category T1 lung adenocarcinoma. MATERIALS AND METHODS. A total of 89 eligible patients with category T1 lung adenocarcinoma were enrolled and classified as patients with BM (n = 35) or patients without BM (n = 54). A total of 1160 quantitative radiomic features were extracted from unenhanced CT images of each patient. Three prediction models (the clinical model, the radiomics model, and a hybrid [clinical plus radiomics] model) were established. The ROC AUC value and 10-fold cross-validation were used to evaluate the prediction performance of the models. RESULTS. In terms of predictive performance, the mean AUC value was 0.759 (95% CI, 0.643-0.867; sensitivity, 82.9%; specificity, 57.4%) for the clinical model, 0.847 (95% CI, 0.739-0.915; sensitivity, 80.0%; specificity, 81.5%) for the radiomics model, and 0.871 (95% CI, 0.767-0.933; sensitivity = 82.9%, specificity = 83.3%) for the hybrid model. The hybrid and radiomics models (p = 0.0072 and 0.0492, respectively) performed significantly better than the clinical model. No significant difference was found between the radiomics model and the hybrid model (p = 0.1022). CONCLUSION. A CT-based radiomics model presented good predictive performance and great potential for predicting BM in patients with category T1 lung adenocarcinoma. As a promising adjuvant tool, it can be helpful for guiding BM screening and thus benefiting personalized surveillance for patients with lung cancer.

Natural history, clinical course and predictors of interval time from initial diagnosis to development of subsequent NSCLC brain metastases

PURPOSE

Non-small cell lung cancer (NSCLC) brain metastases are associated with substantial morbidity and mortality. During recent years, accompanying dramatic improvements in systemic disease control, NSCLC brain metastases have emerged as an increasingly relevant clinical problem. However, optimal surveillance practices remain poorly defined. This purpose of this study was to further characterize the natural history, clinical course and risk factors associated with earlier development of subsequent NSCLC brain metastases to better inform clinical practice and help guide survivorship care.

METHODS

We retrospectively reviewed all institutional NSCLC brain metastasis cases treated with radiotherapy between 1997 and 2015. Exclusion criteria included presence of brain metastases at initial NSCLC diagnosis and incomplete staging information. Interval time to brain metastases and subsequent survival were characterized using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

Among 105 patients within this cohort, median interval time to development of brain metastases was 16 months. Median interval times were 29, 19, 16 and 13 months for Stage I-IV patients, respectively (P = 0.016). Additional independent predictors for earlier development of NSCLC brain metastases included non-adenocarcinomatous histopathology (HR 3.036, P < 0.001), no prior surgical resection (HR 1.609, P = 0.036) and no prior systemic therapy (HR 3.560, P = 0.004). Median survival following intracranial progression was 16 months. Delayed development of brain metastases was associated with better prognosis (HR 0.970, P < 0.001) but not survival following intracranial disease onset.

CONCLUSIONS

Collectively, our results provide valuable insights into the natural history of NSCLC brain metastases. NSCLC stage, histology, prior surgical resection and prior systemic therapy emerged as independent predictors for interval time to brain metastases.

Histopathologic analysis of brain metastasis in pulmonary adenocarcinoma: Necrosis is a new risk factor

BACKGROUND

Studies have shown that 30-50% of non-small cell lung cancer (NSCLC) patients develop brain metastasis (BM). Since BM shortens overall survival and decreases the quality of life, early detection and treatment of BM are vital. While data are available for clinical risk factors of NSCLC with BM, histopathological factors are not well understood. Therefore, we evaluated the histopathological related factors which will help early detection and selection of effective treatment options.

MATERIALS AND METHODS

A total of 117 surgical lung specimens diagnosed as NSCLC with BM were included as a study group. We included 237 cases without BM as a control group. One pathologist reviewed H&E slides and analyzed the histopathologic factors of all cases.

RESULTS

In pulmonary adenocarcinoma, vascular invasion, N stage, micropapillary pattern and necrosis were significantly associated with BM in multivariate analysis (vascular invasion, p = 0.009; micropapillary pattern, p = 0.024; others, p < 0.001). Tumor with extensive necrosis had higher hazard ratio and shorter time to BM (p < 0.001).

CONCLUSION

Our findings suggest that necrosis is a new predictive factor of BM in pulmonary adenocarcinoma. Short term follow-up is needed especially when extensive necrosis is present.

Risk factors for brain metastases in patients with non-small-cell lung cancer

Brain metastases (BM) are severe incidents in patients with non-small-cell lung cancer (NSCLC). The controversial value of prophylactic cranial irradiation (PCI) in NSCLC in terms of survival benefit prompted us to explore the possible risk factors for BM in NSCLC and identify the potential population most likely to benefit from PCI. Risk factors for brain metastases in NSCLC are reviewed in this article. Identifying patients with a higher risk of BM could possibly increase the benefit of PCI while reducing the discomfort and risks caused by unnecessary invasive procedures in the NSCLC patient population. Future studies might focus on finding a solid basis for the prediction of the occurrence of brain metastases and for the therapeutic decision on the use of PCI.

Preventing and treating brain metastases with three first-line EGFR-tyrosine kinase inhibitors in patients with EGFR mutation-positive advanced non-small cell lung cancer

Introduction

Brain metastases (BM) are common in advanced non-small cell lung cancer (NSCLC), and the prognosis is poor with few therapeutic options. This study evaluated the efficacy of three epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in preventing and treating BM in patients with EGFR mutation-positive advanced NSCLC.

Methods

Patients with EGFR mutation-positive advanced NSCLC who visited a tertiary referral center from 1 December 2013 to 30 November 2017 were analyzed retrospectively. They received gefitinib, erlotinib, or afatinib until disease progression, death, or intolerable adverse events. The cumulative incidence of subsequent BM of initial non-BM patients, progression-free survival (PFS), and overall survival (OS) of the BM and non-BM patients were estimated and compared using the Kaplan-Meier and log-rank tests.

Results

306 NSCLC patients were enrolled, with 116, 75, and 115 receiving first-line gefitinib, erlotinib, and afatinib, respectively. The afatinib group had a better PFS [12.7 versus 9.8 months; hazard ratio (HR) 0.59, p = 0.001] and OS (39.1 versus 22.0 months; HR 0.64, p = 0.035) than the gefitinib group. Afatinib tended to provide better BM prevention than gefitinib (BM cumulative incidence, HR 0.49; 95% confidence interval 0.34-0.71, p < 0.001) according to a Cox model adjusted for possible confounders. Patients with initial BM had a shorter PFS (p < 0.001) and OS (p = 0.015) than those without initial BM. Among the former, there were no differences in median PFS (p = 0.34) and median OS (p = 0.46) in the three EGFR-TKI groups.

Conclusions

Our data suggested that, compared with gefitinib, afatinib provided better benefits significantly in terms of PFS and OS. Both had the same effectiveness in preventing subsequent BM.

Patterns of Distant Metastasis Between Histological Types in Esophageal Cancer

Introduction: Distant metastasis remains the major cause of treatment failure in esophageal cancer, though there have been few large-scale studies of the patterns of distant metastasis in different histological types. We investigated the patterns of distant metastasis in esophageal adenocarcinoma (AC) and squamous cell carcinoma (SCC) using a population-based approach.

Methods: Patients with de novo stage IV esophageal cancer at diagnosis were identified using the Surveillance, Epidemiology, and End Results database. Multivariable logistic regression was performed to identify potential risk factors for site-specific distant metastasis to the distant lymph nodes, bone, liver, brain, and lung at diagnosis.

Results: We identified 1,470 patients with complete data for analysis including 1,096 (74.6%) patients with AC and 374 (25.4%) patients with SCC. A total of 2,243 sites of distant metastasis were observed, the liver was the most common site of distant metastasis (727, 32.4%), followed by the distant lymph nodes (637, 28.4%), lung (459, 20.5%), bone (344, 15.3%), and brain (76, 3.4%). Multivariable logistic regression showed that compared to patients with SCC, patients with AC were more likely to have metastasis to the brain (odds ratio [OR] 3.026, 95% confidence interval [CI] 1.441-6.357, p = 0.003) and liver (OR 1.848, 95% CI 1.394–2.451, p < 0.001), and less likely to have metastasis to the lung (OR 0.404, 95% CI 0.316–0.516, p < 0.001). Histological type had no effect on metastasis to the distant lymph nodes or bone.

Conclusions: Patients with esophageal AC are more likely to present with liver and brain metastases, and less likely to present with lung metastasis than patients with esophageal SCC.

Potential Molecular Signatures Predictive of Lung Cancer Brain Metastasis

Brain metastases are the most common tumors of the central nervous system (CNS). Incidence rates vary according to primary tumor origin, whereas the majority of the cerebral metastases arise from primary tumors in the lung (40-50%). Brain metastases from lung cancer can occur concurrently or within months after lung cancer diagnosis. Survival rates after lung cancer brain metastasis diagnosis remain poor, to an utmost of 10 months. Therefore, prevention of brain metastasis is a critical concern in order to improve survival among cancer patients. Although several studies have been made in order to disclose the genetic and molecular mechanisms associated with CNS metastasis, the precise mechanisms that govern the CNS metastasis from lung cancer are yet to be clarified. The ability to forecast, which patients have a higher risk of brain metastasis occurrence, would aid cancer management approaches to diminish or prevent the development of brain metastasis and improve the clinical outcome for such patients. In this work, we revise genetic and molecular targets suitable for prediction of lung cancer CNS disease.

Computed tomography morphologic features of pulmonary adenocarcinoma with brain/bone metastasis

BACKGROUND/AIMS

Brain and bone metastases are common in patients with lung cancer. The development of metastasis is associated with poor survival in lung cancer patients. Although tumor morphologic features on radiographs are routinely assessed for differentiation between benign and malignant lung nodules, they are not used to predict metastasis. We assessed morphologic features of pulmonary adenocarcinomas with brain/bone metastasis on computed tomography (CT) to identify related factors for metastasis.

METHODS

We performed a retrospective analysis of initial chest CT findings (size, type of contour, percentage of necrosis, enhancement, presence or absence of calcification, and air cavity) from 2009 to 2010 of patients with brain or bone metastasis and compared the findings with those of patients without metastases.

RESULTS

In total, 128 patients were included (78 men, 52 women; mean age 69 years; range, 36 to 87). Nineteen patients had brain metastases and 32 had bone metastases. Morphologic features associated with brain metastasis included size ≥ 50 mm (odds ratio [OR], 3.37; 95% confidence interval [CI], 1.24 to 9.17; p = 0.013), necrosis ≥ 30% (OR, 4.51; 95% CI, 1.62 to 12.55; p =0.002), and presence of calcification (OR, 3.97; 95% CI, 1.16 to 13.55; p = 0.035). Morphologic features associated with bone metastasis included necrosis ≥ 30% (OR, 4.639; 95% CI, 1.98 to 10.82; p < 0.001) and T 3 to 4 stage (OR, 2.53; 95% CI, 1.07 to 6.00; p = 0.031).

CONCLUSIONS

We found that necrosis ≥ 30% was associated with pulmonary adenocarcinoma with brain and bone metastasis at initial chest CT morphologic feature. To validate these results, further research should be conducted.

The impact of EGFR mutations on the incidence and survival of stages I to III NSCLC patients with subsequent brain metastasis

Previous studies have demonstrated the association between EGFR mutations and distant metastasis. However, the association for subsequent brain metastasis (BM) in stages I-III non-small cell lung cancer (NSCLC) patients remains inconclusive. We conducted a retrospective analysis to clarify the impact of EGFR mutations on the incidence of BM and associated survival in patients with stage I-III NSCLC. A total of 491 patients screened for EGFR mutations were retrospectively enrolled. Brain MRI or CT was used to detect the BM. Cumulative incidence of subsequent BM and overall survival (OS) after diagnosis of BM were estimated by the Kaplan-Meier method and compared using log-rank test. We performed Cox proportional hazard regression for predictors of subsequent BM and determinants of OS after BM. The cumulative incidence of BM seemed higher in patients harboring EGFR mutations than those without EGFR mutations although it did not reach statistical significance (hazard ratio [HR] = 1.75, 95% confidence interval [CI] = 0.73~1.81). After adjusting possible confounders, including age, smoking, stage, and tumor size, EGFR mutation became one of the predictors for subsequent BM (HR = 1.89, 95% CI = 1.12~3.17, p = 0.017). Though there was no statistical difference in survival after BM between patients with EGFR mutations and wild-type EGFR (median survival: 17.8 vs. 12.2 months, HR = 0.79, 95% CI = 0.45–1.40), patients with EGFR 19 deletion (Del) tended to have a longer survival after BM than the non-EGFR 19 Del group (median survival: 29.4 vs. 14.3 months, HR 0.58, 95% CI = 0.32–1.09, p = 0.089). In conclusion, our data suggested EGFR mutation to be one of the predictors for subsequent BM in stage I-III patients. Given the small sample size, more studies are warranted to corroborate our results.

Risk factors of brain metastasis during the course of EGFR-TKIs therapy for patients with EGFR-mutated advanced lung adenocarcinoma

Controversial value of prophylactic cranial irradiation (PCI) in NSCLC in terms of survival benefit prompted us to explore the possible risk factors for brain metastasis (BM) during the course of EGFR-TKIs therapy from EGFR-mutated advanced lung adenocarcinoma and identify the potential population most likely to benefit from PCI, because BM remains a therapeutically challenging issue. We retrospectively reviewed the records of 134 patients with EGFR-mutated advanced lung adenocarcinoma between 2008 and 2012. The cumulative incidence of BM was calculated by the Kaplan-Meier method, and Multivariate Cox regression analysis was used to assess the independent risk factors for BM. Thirty-four patients (34/134, 25.4%) developed BM during the course of EGFR-TKIs therapy. Moreover, the Multivariate analysis indicated that age ≤ 53 years (HR: 2.751, 95 % CI: 1.326-5.707; p = 0.007), serum carcinoembryonic antigen (CEA) ≥ 23 ng/mL (HR: 3.197, 95 % CI: 1.512-6.758; p = 0.002) and EGFR exon 21 point mutations (HR: 2.769, 95 % CI: 1.355-5.659; p= 0.005) were the independent high-risk factors for developing BM, which could offer important insights into the individualized treatment. Further studies are warranted to validate our findings.

[Clinical Experience with First-generation Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer Patients with Brain Metastasis]

背景与目的

非小细胞肺癌（non-small cell lung cancer, NSCLC）脑转移患者接受一代表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs）的生存数据及影响因素未完全阐明。本研究对存在脑转移的NSCLC患者的生存数据进行分析，以期为指导临床实践提供一定的研究证据。

方法

回顾性收集上海交通大学附属胸科医院2012年-2013年确诊肺癌脑转移并接受一代EGFRTKIs治疗的病例。采用Kaplan-Meier单因素、Cox多因素分析方法，探讨NSCLC脑转移患者接受EGFR-TKIs的生存情况及影响因素。

结果

总体人群中位无进展生存时间（progression-free survival, PFS）为10.0个月（95%CI: 8.3-11.7），中位生存时间（overall survival, OS）为28.0个月（95%CI: 22.9-33.1）。病理组织类型、肿瘤分化程度分别是患者接受EGFR-TKIs后PFS、OS的独立影响因素（P分别为0.001、0.050）。

结论

NSCLC脑转移患者接受一代EGFR-TKIs具有良好的疗效，腺癌亚型患者的PFS长于非腺癌患者，其他肿瘤分化程度患者的OS长于肿瘤低分化患者。

A Nomogram to Predict Brain Metastases of Resected Non-Small Cell Lung Cancer Patients

PURPOSE

Brain metastasis is a major cause leading to the failure of treatment management for non-small cell lung cancer (NSCLC) patients. The goal of this study was to establish an effective nomogram for prediction of brain metastases of resected NSCLC patients.

METHODS

We retrospectively investigated 637 operable NSCLC patients who received treatment at Zhejiang Cancer Hospital, China. A Cox proportional hazards regression model was performed to identify significant risk factors, and a nomogram was developed for predicting 3- and 5-year brain metastases rates.

RESULTS

Multivariate analysis identified four independent risk factors: neuron-specific enolase, histological type, number of metastatic lymph nodes, and tumor grade, and a nomogram was developed based on these factors. The effectiveness of the nomogram was validated using an internal bootstrap resampling approach, showing that the nomogram exhibited a sufficient level of discrimination according to the C-index (0.74, 95 % confidence interval 0.67-0.82).

CONCLUSIONS

The nomogram developed in this study demonstrated its discrimination capability for predicting 3- and 5-year occurrence of brain metastases, and can be used to identify high-risk patients.

Probabilistic modeling of short survivability in patients with brain metastasis from lung cancer

The prediction of substantially short survivability in patients is extremely risky. In this study, we proposed a probabilistic model using Bayesian network (BN) to predict the short survivability of patients with brain metastasis from lung cancer. A nationwide cancer patient database from 1996 to 2010 in Taiwan was used. The cohort consisted of 438 patients with brain metastasis from lung cancer. We utilized synthetic minority over-sampling technique (SMOTE) to solve the imbalanced property embedded in the problem. The proposed BN was compared with three competitive models, namely, naive Bayes (NB), logistic regression (LR), and support vector machine (SVM). Statistical analysis showed that performances of BN, LR, NB, and SVM were statistically the same in terms of all indices with low sensitivity when these models were applied on an imbalanced data set. Results also showed that SMOTE can improve the performance of the four models in terms of sensitivity, while keeping high accuracy and specificity. Further, the proposed BN is more effective as compared with NB, LR, and SVM from two perspectives: the transparency and ability to show the relation of factors affecting brain metastasis from lung cancer; it allows decision makers to find the probability despite incomplete evidence and information; and the sensitivity of the proposed BN is the highest among all standard machine learning methods.

Prophylactic cranial irradiation: recent outcomes and innovations

Brain metastases represent a frequent problem in several malignancies. They can shorten survival while causing significant morbidity and impairment in the patient's quality of life. Prophylactic cranial irradiation (PCI) has become an integral part of the standard of care in small cell lung cancer (SCLC), yet its role in other malignancies remains the subject of significant discussion. Its role has been extensively investigated in non-small cell lung cancer and less so for breast cancer and other malignancies. Improvements in medical care as well as in whole brain radiotherapy (WBRT) techniques may improve the risk-benefit ratio of this therapy so as to expand its role in cancer care. The use of memantine in WBRT patients as well as the use of hippocampal avoidance techniques are of particular interest in this effort. Herein, we review the history of PCI, its current use, and areas of investigation in the application of PCI.

Potential toxicities of prophylactic cranial irradiation

Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brain metastasis (BM) and increases survival of patients with limited and extensive-disease small-cell lung cancer (SCLC) that showed any response to chemotherapy. PCI is currently not applied in non-small-cell lung cancer (NSCLC) since it has not proven to significantly improve OS rates in stage IIIA/B, although novel data suggest that subgroups that could benefit may exist. Here we briefly review potential toxicities of PCI which have to be considered before prescribing PCI. They are mostly difficult to delineate from pre-existing risk factors which include preceding chemotherapy, patient age, paraneoplasia, as well as smoking or atherosclerosis. On the long run, this will force radiation oncologists to evaluate each patient separately and to estimate the individual risk. Where PCI is then considered to be of benefit, novel concepts, such as intensity-modulated radiotherapy and/or neuroprotective drugs with potential to lower the rates of side effects will eventually be superior to conventional therapy. This in turn will lead to a re-evaluation whether benefits might then outweigh the (lowered) risks.

A nomogram to predict brain metastasis as the first relapse in curatively resected non-small cell lung cancer patients

OBJECTIVES

Development of brain metastasis results in a significant reduction in overall survival. However, there is no an effective tool to predict brain metastasis in non-small cell lung cancer (NSCLC) patients. We conducted this study to develop a feasible nomogram that can predict metastasis to the brain as the first relapse site in patients with curatively resected NSCLC.

MATERIAL AND METHODS

A retrospective review of NSCLC patients who had received curative surgery at National Cancer Center (Goyang, South Korea) between 2001 and 2008 was performed. We chose metastasis to the brain as the first relapse site after curative surgery as the primary endpoint of the study. A nomogram was modeled using logistic regression.

RESULTS

Among 1218 patients, brain metastasis as the first relapse developed in 87 patients (7.14%) during the median follow-up of 43.6 months. Occurrence rates of brain metastasis were higher in patients with adenocarcinoma or those with a high pT and pN stage. Younger age appeared to be associated with brain metastasis, but this result was not statistically significant. The final prediction model included histology, smoking status, pT stage, and the interaction between adenocarcinoma and pN stage. The model showed fairly good discriminatory ability with a C-statistic of 69.3% and 69.8% for predicting brain metastasis within 2 years and 5 years, respectively. Internal validation using 2000 bootstrap samples resulted in C-statistics of 67.0% and 67.4% which still indicated good discriminatory performances.

CONCLUSION

The nomogram presented here provides the individual risk estimate of developing metastasis to the brain as the first relapse site in patients with NSCLC who have undergone curative surgery. Surveillance programs or preventive treatment strategies for brain metastasis could be established based on this nomogram.