Impact of EGFR Mutation and ALK Translocation on Recurrence Pattern After Definitive Chemoradiotherapy for Inoperable Stage III Non-squamous Non–small-cell Lung Cancer

Targeted treatment for unresectable EGFR mutation-positive stage III non-small cell lung cancer: Emerging evidence and future perspectives

Epidermal growth factor receptor (EGFR) mutations are detected in up to one third of patients with unresectable stage III non-small cell lung cancer (NSCLC). The current standard of care for unresectable stage III NSCLC is consolidation durvalumab for patients who have not progressed following concurrent chemoradiotherapy (the 'PACIFIC regimen'). However, the benefit of immunotherapy, specifically in patients with EGFR mutation-positive (EGFRm) tumors, is not well characterized, and this treatment approach is not recommended in these patients, based on a recent ESMO consensus statement. EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated significant improvements in patient outcomes in EGFRm metastatic NSCLC. The benefits of these agents have also translated to patients with EGFRm early-stage resectable disease as adjuvant therapy. The role of EGFR-TKIs has yet to be prospectively characterized in the unresectable setting. Preliminary efficacy signals for EGFR-TKIs in unresectable EGFRm stage III NSCLC have been reported from a limited number of subgroup and retrospective studies. Several clinical trials are ongoing assessing the safety and efficacy of EGFR-TKIs in this patient population. Here, we review the current management of unresectable EGFRm stage III NSCLC. We outline the rationale for investigating EGFR-TKI strategies in this setting and discuss ongoing studies. Finally, we discuss the evidence gaps and future challenges for treating patients with unresectable EGFRm stage III NSCLC.

Generating immunogenomic data-guided virtual patients using a QSP model to predict response of advanced NSCLC to PD-L1 inhibition

Generating realistic virtual patients from a limited amount of patient data is one of the major challenges for quantitative systems pharmacology modeling in immuno-oncology. Quantitative systems pharmacology (QSP) is a mathematical modeling methodology that integrates mechanistic knowledge of biological systems to investigate dynamics in a whole system during disease progression and drug treatment. In the present analysis, we parameterized our previously published QSP model of the cancer-immunity cycle to non-small cell lung cancer (NSCLC) and generated a virtual patient cohort to predict clinical response to PD-L1 inhibition in NSCLC. The virtual patient generation was guided by immunogenomic data from iAtlas portal and population pharmacokinetic data of durvalumab, a PD-L1 inhibitor. With virtual patients generated following the immunogenomic data distribution, our model predicted a response rate of 18.6% (95% bootstrap confidence interval: 13.3-24.2%) and identified CD8/Treg ratio as a potential predictive biomarker in addition to PD-L1 expression and tumor mutational burden. We demonstrated that omics data served as a reliable resource for virtual patient generation techniques in immuno-oncology using QSP models.

Generating immunogenomic data-guided virtual patients using a QSP model to predict response of advanced NSCLC to PD-L1 inhibition

Generating realistic virtual patients from a limited amount of patient data is one of the major challenges for quantitative systems pharmacology modeling in immuno-oncology. Quantitative systems pharmacology (QSP) is a mathematical modeling methodology that integrates mechanistic knowledge of biological systems to investigate dynamics in a whole system during disease progression and drug treatment. In the present analysis, we parameterized our previously published QSP model of the cancer-immunity cycle to non-small cell lung cancer (NSCLC) and generated a virtual patient cohort to predict clinical response to PD-L1 inhibition in NSCLC. The virtual patient generation was guided by immunogenomic data from iAtlas portal and population pharmacokinetic data of durvalumab, a PD-L1 inhibitor. With virtual patients generated following the immunogenomic data distribution, our model predicted a response rate of 18.6% (95% bootstrap confidence interval: 13.3-24.2%) and identified CD8/Treg ratio as a potential predictive biomarker in addition to PD-L1 expression and tumor mutational burden. We demonstrated that omics data served as a reliable resource for virtual patient generation techniques in immuno-oncology using QSP models.

Real-world treatment patterns and clinical outcomes in EGFR-mutant locally advanced lung adenocarcinoma: A multi-center cohort study

Objective

To investigate the optimal management of patients with epidermal growth factor receptor gene (EGFR) mutant locally advanced non-small cell lung cancer (LA-NSCLC).

Methods

Patients with unresectable stage III lung adenocarcinoma (LAC) harboring EGFR mutations from 2012 to 2018 were analyzed retrospectively, and were categorized into three groups according to the primary treatment: chemoradiotherpy (CRT) (group 1), combined radiation therapy (RT) and EGFR-tyrosine kinase inhibitors (TKI) with/without chemotherapy (group 2), and EGFR-TKI alone until tumor progression (group 3). Inverse probability of multiple treatment weighting (IPTW) of propensity score was used to compare overall survival (OS) and progression free survival (PFS) between treatments and account for confounding.

Results

A total of 104, 105, and 231 patients were categorized into groups 1, 2, and 3, respectively. After IPTW adjustment, the median PFS for each group was 12.4, 26.2, and 16.2 months (log-rank P < 0.001), and the median OS was 51.0, 67.4 and 49.3 months (log-rank P = 0.084), respectively. Compared with those in group 1, patients in group 2 had significantly improved PFS [adjusted hazard ratio HR (aHR), 0.40; 95% confidence interval (CI): 0.29, 0.54; P < 0.001] and OS (aHR, 0.61; 95% CI: 0.38, 0.98; P = 0.039). Patients in group 3 had prolonged PFS (aHR, 0.66; 95% CI: 0.50, 0.87; P = 0.003), but not OS (aHR, 0.90; 95% CI: 0.62, 1.32; P = 0.595). Doubly robust IPTW analysis and multivariable Cox regression analysis yielded similar findings.

Conclusions

EGFR-TKIs after chemoradiation or combined with radiation alone correlated with the longest PFS and OS (versus CRT or TKIs alone) in patients with EGFR-mutant unresectable LA-NSCLC. Well-designed prospective trials were warranted.

Stereotactic ablative radiotherapy for acquired resistance to EGFR therapy in metastatic non-small cell lung cancer

The advent of targeted therapy has transformed the treatment paradigm and survival of patients with metastatic non-small cell lung cancer (NSCLC) with driver mutations. The development of acquired resistances during treatment with tyrosine kinase inhibitors (TKIs) impedes a prolonged survival in many patients. This fact is leading to the use of locally ablative therapies such as stereotactic ablative radiotherapy (SABR) to counter these resistances. SABR is a non-invasive treatment that can be delivered in multiple locations and has already proven effective in oligometastatic disease. Clinical evidence suggests that the combination of SABR with TKIs prolongs progression-free survival (PFS) in metastatic NSCLC patients with mutations in epidermal growth factor receptor (EGFR), with international guidelines recommending their use in unfavorable scenarios such as oligoprogressive disease. In this publication, we have reviewed the available evidence on EGFR-TKIs resistance mechanisms and the combination of SABR with TKI in metastatic NSCLC with EGFR mutations. We also describe the utility and clinical recommendations of this combination in oligometastatic and oligoprogressive disease.

Pattern of failure and clinical value of local therapy for oligo‐recurrence in locally advanced non‐small cell lung cancer after definitive chemoradiation: Impact of driver mutation status

INTRODUCTION

Considerable differences of treatment response and pattern of failure may exist between definitive chemoradiation (CRT) treated locally advanced non-small cell lung cancer (LA-NSCLC) patients. The clinical value of additional tyrosine kinase inhibitors (TKIs) before disease recurrence and salvage local therapy after initial recurrent disease remain controversial.

METHODS AND MATERIALS

Consecutive LA-NSCLC patients receiving definitive CRT and having definite results about driver mutations (EGFR, ALK and ROS1) were retrospectively reviewed. Initial recurrent disease was classified as in-field recurrence, out-of-field recurrence and distant metastasis. Recurrent disease occurred only in the brain or limited to ≤3 extra-cranial organs and ≤5 extra-cranial lesions, was defined as oligo-recurrence. Progression free survival and overall survival (OS) were calculated from diagnosis to disease progression or death, and to death, respectively. OS2 was measured from initial disease recurrence to death among patients who had recurrent disease.

RESULTS

Of the 153 enrolled patients, 39 had driver mutations and 13 received additional TKI therapy besides definitive CRT. Patients harboring driver mutations but without additional TKI therapy had a similar PFS and significantly longer OS (p = 0.032) than those without driver mutations. Additional TKI therapy prolonged PFS (p = 0.021) but not OS among patients with driver mutations. No significant difference of pattern of failure was observed between patient subgroups stratified by the status of driver mutations and the usage of additional TKI therapy. Furthermore, 57 of the 95 patients with initial recurrent disease developed oligo-recurrence and salvage local therapy significantly improved OS2 (p = 0.01) among patients with oligo-recurrence disease.

CONCLUSION

LA-NSCLC patients receiving definitive CRT generally had similar PFS and pattern of treatment failure, regardless of driver mutation status. Additional TKI therapy besides definitive CRT could prolong PFS but not OS. The majority of recurrent disease after definitive CRT belongs to oligo-recurrence and salvage local therapy may provide survival benefit.

Radioresistance of Non-Small Cell Lung Cancers and Therapeutic Perspectives

Survival in unresectable locally advanced stage non-small cell lung cancer (NSCLC) patients remains poor despite chemoradiotherapy. Recently, adjuvant immunotherapy improved survival for these patients but we are still far from curing most of the patients with only a 57% survival remaining at 3 years. This poor survival is due to the resistance to chemoradiotherapy, local relapses, and distant relapses. Several biological mechanisms have been found to be involved in the chemoradioresistance such as cancer stem cells, cancer mutation status, or the immune system. New drugs to overcome this radioresistance in NSCLCs have been investigated such as radiosensitizer treatments or immunotherapies. Different modalities of radiotherapy have also been investigated to improve efficacity such as dose escalation or proton irradiations. In this review, we focused on biological mechanisms such as the cancer stem cells, the cancer mutations, the antitumor immune response in the first part, then we explored some strategies to overcome this radioresistance in stage III NSCLCs with new drugs or radiotherapy modalities.

Improved survival in patients with unresectable stage III EGFR-mutant adenocarcinoma with upfront EGFR-tyrosine kinase inhibitors

BACKGROUND

Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have been the standard treatment for advanced EGFR-mutant adenocarcinoma, the effects of upfront EGFR-TKI use in unresectable stage III EGFR-mutant adenocarcinoma remain unexplored. Here, we conducted a retrospective study to compare different treatment strategies in these patients.

METHODS

From October 2010 to June 2019, patients with unresectable stage III adenocarcinoma who received treatment at a tertiary referral center were enrolled. Patients were classified into three groups: EGFR-mutant adenocarcinoma treated with concurrent chemoradiotherapy (group 1) or EGFR-TKI (group 2) and EGFR wild-type adenocarcinoma treated with concurrent chemoradiotherapy (group 3). Progression-free survival, progression-free survival-2, and overall survival were estimated and compared using Kaplan-Meier and log-rank tests.

RESULTS

A total of 92 patients were enrolled; 10, 40, and 42 patients were assigned to groups 1, 2, and 3, respectively. Patients with EGFR mutations who received upfront EGFR-TKIs had significantly longer progression-free and overall survival than those who received upfront concurrent chemoradiotherapy (hazard ratio 0.33 vs. 0.34, p = 0.006 vs. 0.031) according to a Cox model adjusted for possible confounders. Moreover, upfront concurrent chemoradiotherapy did not lead to higher survival rates in patients with EGFR mutations than in those with EGFR wild-type adenocarcinoma (progression-free survival; hazard ratio 0.37, p = 0.036; overall survival; hazard ratio 0.35, p = 0.080) by Cox regression analysis.

CONCLUSION

This current study suggests that EGFR-TKIs is a better choice for patients with unresectable stage III EGFR-mutant adenocarcinoma. However, further randomized studies are required to validate the results.

Development and validation of a prediction model using molecular marker for long-term survival in unresectable stage III non-small cell lung cancer treated with chemoradiotherapy

Background

This study aimed to establish a predictive nomogram integrating epidermal growth factor receptor (EGFR) mutation status for 3‐ and 5‐year overall survival (OS) in unresectable/inoperable stage III non‐small cell lung cancer (NSCLC) treated with definitive chemoradiotherapy.

Methods

A total of 533 stage III NSCLC patients receiving chemoradiotherapy from 2013 to 2017 in our institution were included and divided into training and testing sets (2:1). Significant factors impacting OS were identified in the training set and integrated into the nomogram based on Cox proportional hazards regression. The model was subject to bootstrap internal validation and external validation within the testing set and an independent cohort from a phase III trial. The accuracy and discriminative capacity of the model were examined by calibration plots, C‐indexes and risk stratifications.

Results

The final multivariate model incorporated sex, smoking history, histology (including EGFR mutation status), TNM stage, planning target volume, chemotherapy sequence and radiation pneumonitis grade. The bootstrapped C‐indexes in the training set were 0.688, 0.710 for the 3‐ and 5‐year OS. For external validation, C‐indexes for 3‐ and 5‐year OS were 0.717, 0.720 in the testing set and 0.744, 0.699 in the external testing cohort, respectively. The calibration plots presented satisfying accuracy. The derivative risk stratification strategy classified patients into distinct survival subgroups successfully and performed better than the traditional TNM staging.

Conclusions

The nomogram incorporating EGFR mutation status could facilitate survival prediction and risk stratification for individual stage III NSCLC, providing information for enhanced immunotherapy decision and future trial design.

Update on adjuvant therapy in completely resected NSCLC patients

In patients with completely resected non‐small cell lung cancer (NSCLC), postoperative adjuvant chemotherapy has been associated with improvement in survival by minimizing the risk of recurrence. For years, systemic chemotherapy including platinum based regimen has been a mainstay treatment modality of adjuvant treatment after complete resection. ADAURA study showed that among completely resected IB to IIIA NSCLC, disease‐free survival was significantly better in patients under adjuvant osimertinib than a placebo group. After the advent of a variety of new treatment regimens, such as third generation TKI and immunotherapy, the landscape of postoperative adjuvant treatment has been changing. In this review, we discuss some key issues regarding choice of adjuvant treatment after complete resection in NSCLC, and provide further updates on recent advances in treatment modalities.

Comparative Efficacy of Systemic Agents for Brain Metastases From Non-Small-Cell Lung Cancer With an EGFR Mutation/ALK Rearrangement: A Systematic Review and Network Meta-Analysis

BACKGROUND

Brain metastases (BM) from non-small-cell lung cancer (NSCLC) are frequent and carry significant morbidity, and current management options include varying local and systemic therapies. Here, we performed a systematic review and network meta-analysis to determine the ideal treatment regimen for NSCLC BMs with targetable EGFR-mutations/ALK-rearrangements.

METHODS

We searched MEDLINE, EMBASE, Web of Science, ClinicalTrials.gov, CENTRAL and references of key studies for randomized controlled trials (RCTs) published from inception until June 2020. Comparative RCTs including ≥10 patients were selected. We used a frequentist random-effects model for network meta-analysis (NMA) and assessed the certainty of evidence using the GRADE approach. Our primary outcome of interest was intracranial progression-free survival (iPFS).

RESULTS

We included 24 studies representing 19 trials with 1623 total patients. Targeted tyrosine kinase inhibitors (TKIs) significantly improved iPFS, with second-and third- generation TKIs showing the greatest benefit (HR=0.25, 95%CI 0.15-0.40). Overall PFS was also improved compared to conventional chemotherapy (HR=0.47, 95%CI 0.36-0.61). In EGFR-mutant patients, osimertinib showed the greatest benefit in iPFS (HR=0.32, 95%CI 0.15-0.69) compared to conventional chemotherapy, while gefitinib + chemotherapy showed the greatest overall PFS benefit (HR=0.26, 95%CI 0.10-0.70). All ALKi improved overall PFS compared to conventional chemotherapy, with alectinib having the greatest benefit (HR=0.13, 95%CI 0.07-0.24).

CONCLUSIONS

In patients with NSCLC BMs and EGFR/ALK mutations, targeted TKIs improve intracranial and overall PFS compared to conventional modalities such as chemotherapy, with greater efficacy seen using newer generations of TKIs. This data is important for treatment selection and patient counseling, and highlights areas for future RCT research.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=179060.

Recent advances and new insights in the management of early-stage epidermal growth factor receptor-mutated non-small-cell lung cancer

Patients with early-stage non-small-cell lung cancer (NSCLC) are candidates for curative surgery; however, despite multiple advances in lung cancer management, recurrence rates remain high. Adjuvant chemotherapy has been demonstrated to significantly prolong overall survival (OS), but this benefit is modest and there is an urgent need for effective new therapies to provide a cure for more patients. The high efficacy of tyrosine kinase inhibitors (TKIs) against epidermal growth factor receptor-mutated (EGFR) in patients with advanced EGFR-mutated NSCLC has led to the evaluation of these agents in early stages of the disease. Multiple clinical trials have evaluated the safety and efficacy of EGFR TKIs as an adjuvant treatment, in patients with resected EGFR-mutated NSCLC, and shown that they significantly prolong disease-free survival (DFS), but this benefit does not translate to OS. Recently, an interim analysis of the ADAURA trial demonstrated that, surprisingly, osimertinib improved DFS. This led to the study being stopped early, leaving many unanswered questions about its potential effect on OS and its incorporation as a standard adjuvant treatment in this patient subgroup. These targeted agents are also being evaluated in locally-advanced disease, with promising results, although prospective studies with larger sample sizes are needed to confirm these results. In this article, we review the most relevant studies on the role of EGFR TKIs in the management of early-stage EGFR-mutated NSCLC.

EGFR-mutated stage IV non-small cell lung cancer: What is the role of radiotherapy combined with TKI?

Lung cancer is the leading cause of cancer‐related death globally and poses a considerable threat to public health. Asia has the highest prevalence of epidermal growth factor receptor (EGFR) mutations in patients with non‐small cell lung cancer (NSCLC). Despite the reasonable response and prolonged survival associated with EGFR‐tyrosine kinase inhibitor (TKI) therapy, the acquisition of resistance to TKIs remains a major challenge. Additionally, patients with EGFR mutations are at a substantially higher risk of brain metastasis compared with those harboring wild‐type EGFR. The role of radiotherapy (RT) in EGFR‐mutated (EGFRm) stage IV NSCLC requires clarification, especially with the advent of next‐generation TKIs, which are more potent and exhibit greater central nervous system activity. In particular, the feasible application of RT, including the timing, site, dose, fraction, and combination with TKI, merits further investigation. This review focuses on these key issues, and provides a flow diagram with proposed treatment options for metastatic EGFRm NSCLC, aiming to provide guidance for clinical practice.

Gefitinib induction followed by chemoradiotherapy in EGFR-mutant, locally advanced non-small-cell lung cancer: LOGIK0902/OLCSG0905 phase II study

Background

The role of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) induction coupled with standard concurrent chemoradiotherapy (CRT) is unclear in unresectable, stage III, EGFR-mutant non-small-cell lung cancer (NSCLC). Therefore, a phase II trial was conducted to evaluate the efficacy and safety of gefitinib induction followed by CRT in this disease setting.

Patients and methods

Patients with unresectable, EGFR-mutant, stage III NSCLC were administered gefitinib monotherapy (250 mg/day) for 8 weeks. Subsequently, patients without disease progression during induction therapy were administered cisplatin and docetaxel (40 mg/m² each) on days 1, 8, 29, and 36 with concurrent radiotherapy at a total dose of 60 Gy. The primary endpoint was the 2-year overall survival (OS) rate, which was hypothesized to reach 85%, with a threshold of the lower limit of 60%.

Results

Twenty patients (median age: 66 years; male/female: 9/11; histology: 20 adenocarcinoma; stage IIIA/IIIB: 9/11; and exon 19/21: 10/10) were enrolled. The 2-year OS rate was 90% (90% confidence interval: 71.4% to 96.8%), indicating that this trial met the primary objective. The overall response rate and 1- and 2-year progression-free survival rates were 85.0%, 58.1%, and 36.9%, respectively. Grade ≥3 adverse events (>10%) included hepatic toxicity during the induction phase and neutropenia and febrile neutropenia in the CRT phase. Radiation pneumonitis grade ≥3 or treatment-related death did not occur.

Conclusions

This is the first prospective study to demonstrate the favorable efficacy and safety of EGFR-TKI induction followed by standard CRT in EGFR-mutant, stage III NSCLC. Further confirmatory studies are needed.

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This is the first prospective study evaluating gefitinib induction followed by CRT in EGFR-mutated, locally advanced NSCLC.

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The 2-year OS rate was 90% (90% confidence interval: 71.4% to 96.8%), indicating that this trial met the primary objective.

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The objective response rate throughout the treatment protocol was 85.0% (17 of 20).

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The safety findings were consistent with the known safety profiles of all agents administered.

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Our results might raise a critical point that needs to be evaluated in further studies to improve the cure rate.

Narrative review of the emerging role of molecular biomarkers in guiding the definitive management of unresectable non-small cell lung cancer

The addition of PD-L1 targeting consolidation therapy to previously standard of care concurrent chemoradiation for locally advanced, unresectable non-small cell lung cancer resulted in dramatic improvements in clinical outcomes. However, in contrast to patients with metastatic disease, the application of immunotherapies is not currently guided by molecular characteristics of patient tumors. Furthermore, despite increasing awareness of predictive and/or prognostic genomic alterations in patients with locally advanced disease, the utility of targeted therapies, such as those aimed at alterations in EGFR or ALK, remains unclear in this subset of patients. As a result, patients with unresectable, locally advanced non-small cell lung cancer are treated uniformly according to histology, regardless of other molecular features despite the potential for treatment-associated risks without a clear benefit. Here, we first discuss the advantages of utilizing molecular biomarkers to guide treatment of non-small cell lung cancer based on treatment outcomes in the metastatic setting. Next, we review preclinical and retrospective clinical data that supports potential further personalization of these treatment strategies in earlier stages of disease. Finally, we discuss some of the ongoing clinical trials attempting to address these hypotheses prospectively.

Differences in failure patterns according to the EGFR mutation status after proton beam therapy for early stage non-small cell lung cancer

We analyzed 135 patients (including 27 EGFR-mutant and 29 EGFR-wild) with T1-3N0M0 non-squamous NSCLC treated by PBT. Considering the 3-year cumulative incidence, the EGFR-mutant group showed a significantly lower infield failure rate (9% vs 27%, p = 0.02) and higher out-of-field failure rate (67% vs 40%, p = 0.02) than the EGFR-wild group.

Predictive model of the first failure pattern in patients receiving definitive chemoradiotherapy for inoperable locally advanced non-small cell lung cancer (LA-NSCLC)

Purpose

To analyze patterns of failure in patients with LA-NSCLC who received definitive chemoradiotherapy (CRT) and to build a nomogram for predicting the failure patterns in this population of patients.

Materials and methods

Clinicopathological data of patients with LA-NSCLC who received definitive chemoradiotherapy and follow-up between 2013 and 2016 in our hospital were collected. The endpoint was the first failure after definitive chemoradiotherapy. With using elastic net regression and 5-fold nested cross-validation, the optimal model with better generalization ability was selected. Based on the selected model and corresponding features, a nomogram prediction model was built. This model was also validated by ROC curves, calibration curve and decision curve analysis (DCA).

Results

With a median follow-up of 28 months, 100 patients experienced failure. There were 46 and 54 patients who experience local failure and distant failure, respectively. Predictive model including 9 factors (smoking, pathology, location, EGFR mutation, age, tumor diameter, clinical N stage, consolidation chemotherapy and radiation dose) was finally built with the best performance. The average area under the ROC curve (AUC) with 5-fold nested cross-validation was 0.719, which was better than any factors alone. The calibration curve revealed a satisfactory consistency between the predicted distant failure rates and the actual observations. DCA showed most of the threshold probabilities in this model were with good net benefits.

Conclusion

Clinicopathological factors could collaboratively predict failure patterns in patients with LA-NSCLC who are receiving definitive chemoradiotherapy. A nomogram was built and validated based on these factors, showing a potential predictive value in clinical practice.

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.