EGFR mutation status and survival after diagnosis of brain metastasis in nonsmall cell lung cancer

Clinical factors associated with mortality within three months after radiosurgery of asymptomatic brain metastases from non-small cell lung cancer

PURPOSE

Routine brain MRI surveillance frequently diagnoses small, asymptomatic brain metastases from non-small cell lung cancer (NSCLC) that are effectively treated with stereotactic radiosurgery (SRS). A subset of patients, however, may die prior to the onset of symptoms. This study identifies clinical features that distinguish neurologically-asymptomatic NSCLC brain metastases patients that die prior to routine 3 month follow-up after SRS.

METHODS

Retrospective chart review from 2007 to 2017 identified 18 patients with neurologically-asymptomatic NSCLC brain metastases who died < 3 months after SRS. Twenty-eight additional patients meeting criteria and surviving > 6 months after SRS were identified. Clinical factors were examined to determine characteristics correlated with survival using cox proportional hazards and nominal logistic regression models. Logistic regression models using salient factors were trained with 10-fold cross-validation and compared to the graded prognostic assessment (GPA) and score index of radiosurgery (SIR) using the AUC from receiver operant characteristic curves.

RESULTS

The median survival following SRS was 1.4 and 9.2 months for the < 3 months and > 6 months groups, respectively. Age, number of brain metastases, and Karnofsky performance status were associated with overall survival while gender and interval between primary cancer and first brain metastasis diagnoses were associated with < 3 months and > 6 months survival, respectively. Models using GPA and SIR performed poorly compared to preliminary metrics generated in this study for prognosis of both < 3 months and > 6 months survival.

CONCLUSION

Physicians require data to provide high-value, cost-conscious health care. Clinical metrics can screen patients with asymptomatic NSCLC brain metastases likely to die prior to the standard screening interval and observation could be considered.

Efficacy of brain radiotherapy plus EGFR-TKI for EGFR-mutated non-small cell lung cancer patients who develop brain metastasis

INTRODUCTION

To analyze the appropriate treatment methods or timing to use epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and brain radiation treatment (RT) for symptomatic and asymptomatic brain metastases (BM) in patients with EGFR mutation non-small cell lung cancer (NSCLC).

MATERIAL AND METHODS

We retrospectively studied patients diagnosed with EGFR gene mutated NSCLC who developed brain metastasis between June 2006 and December 2015 at Zhejiang Cancer Hospital. Treatment data were assessed in 181 patients with 49 symptomatic BM and 132 asymptomatic BM retrospectively.

RESULTS

In 49 symptomatic BM patients, the median OS of the stereotactic radiosurgery (SRS)-treated group was longer than in the whole brain radiotherapy (WBRT) group (37.7 vs. 21.1 months) (p = 0.194). In the group of 132 asymptomatic brain metastasis patients, the median overall survival (mOS) was longer in upfront brain radiotherapy compared with the upfront TKI group (24.9 vs. 17.4 months) (p = 0.035). In further analysis regarding the timing of using radiotherapy, out of all 74 patients, 33 underwent concurrent TKI and brain radiation, 13 received TKI after first-line RT treatment and 28 patients received radiotherapy after TKI failure. The intracranial progression free survival (iPFS) of the three groups was 11.1 months, 11.3 months and 8.1 months (p = 0.032), respectively. The mOS of the three groups was 21.9 months, 26.2 months and 17.1 months, respectively (p = 0.085).

CONCLUSIONS

Our research indicated that delayed brain RT may result in inferior iPFS in EGFR mutated NSCLC patients with asymptomatic brain metastases, but no OS benefit was obtained. In addition, our study revealed that patients treated with SRS had a significantly longer OS for symptomatic BM. Future prospective study of the optimal management strategy with WBRT or SRS and TKI for this patient cohort is urgently needed.

Treating EGFR-Mutated Oncogene-Addicted Advanced Non-Small-Cell Lung Cancer in the Era of Economic Crisis in Greece: Challenges and Opportunities

PURPOSE

Because of the profound financial crisis that commenced in Greece in 2010, severe cuts in health care spending and other restriction measures led to significant delays in the reimbursement of novel antineoplastic agents. In 2011, the Hellenic Society of Medical Oncology initiated a program of early access to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors for the treatment of patients with advanced, EGFR-mutant non-small-cell lung cancer (NSCLC). We evaluated treatment patterns and clinical outcomes in patients with EGFR-mutant or wild-type disease treated at a large center in Greece throughout the period of financial crisis.

PATIENTS AND METHODS

From 2011 through 2015, 252 patients with newly diagnosed advanced NSCLC were treated at the Department of Medical Oncology of the Papageorgiou Hospital, a tertiary cancer center in northern Greece. We retrospectively reviewed patient medical records to obtain clinicopathologic characteristics, EGFR mutation status, and follow-up data. The primary end point was time to treatment failure.

RESULTS

Of the 198 evaluable patients, 25 (12%) had EGFR mutations. All patients with EGFR mutations except one received treatment with an EGFR tyrosine kinase inhibitor. Median times to treatment failure for patients with EGFR-mutant and wild-type disease were 15.8 and 7.1 months, respectively (hazard ratio, 0.58; 95% CI, 0.35 to 0.95; P = .031). There was no difference in overall survival between the two groups ( P = .293). No deviation from treatment guidelines or discontinuation of treatment regimens occurred because of logistic reasons or drug shortages.

CONCLUSION

Despite restrictions in the reimbursement policy and accompanying controls in the use of high-cost medicines, the national program enabled treatment of patients with EGFR-mutant NSCLC according to established guidelines. Therefore, the clinical outcomes of such patients treated in Greece during the economic crisis were in accordance with international standards.

Clinicopathological and genetic characteristics associated with brain metastases from lung adenocarcinoma and utility as prognostic factors

Brain metastases (BM) are common in patients with lung adenocarcinoma, and represent a significant cause of morbidity in the disease. A more comprehensive understanding of the clinicopathological characteristics that serve as prognostic factors for survival in patients with BM from lung adenocarcinoma may aid in informing treatment strategies for this patient population. In the present study, clinicopathological factors, including EGFR mutation status, were evaluated in 59 patients who were diagnosed with BM from lung adenocarcinoma, and underwent BM resection between January 1985 and December 2014 at Fukuoka University Hospital. The most frequent subtype of BM from lung adenocarcinoma was solid adenocarcinoma (57.6%), followed by papillary adenocarcinoma (22.0%) and acinar adenocarcinoma (18.6%). A total of 14 patients (23.7%) exhibited EGFR mutations, which were significantly associated with female sex (9/14, 64.3%), non-smoker status (8/14, 57.1%), BM in the frontal lobes (9/14, 64.3%) and papillary adenocarcinoma (5/14, 35.7%). Statistical analysis revealed a significant association between non-smoker status and BM in the frontal lobes, and more favorable disease prognosis. The results of the present study suggest that histological and genetic analysis of tissue from BM provides information useful for managing treatment of patients with resectable BM arising from lung adenocarcinoma.

CNS Metastases in Epidermal Growth Factor Receptor Mutation-Positive Non-Small-Cell Lung Cancer: Impact on Health Resource Utilization

PURPOSE

Patients with epidermal growth factor receptor (EGFR) mutation-positive (EGFRm) non-small-cell lung cancer commonly experience disease progression in the CNS. Here, we assess the impact of CNS disease on resource utilization and outcomes in patients who are EGFRm.

METHODS

We completed a retrospective review of all advanced patients who were EGFRm, referred to BC Cancer, and treated with a first- and/or second-generation EGFR tyrosine kinase inhibitor from 2010 to 2015. Baseline characteristics, systemic treatment, and CNS management were collected. We compared health resource utilization (HRU) between patients with CNS-negative disease and those with CNS metastases from the median time of CNS metastases diagnosis to death or last follow-up (9.1 months) and at 9 months preceding death or last follow-up for the CNS-negative group.

RESULTS

Four hundred ninety-nine patients were referred, of which 68% were female; 51% were of Asian ethnicity; and 57%, 37%, and 6% were exon 19, 21, or other, respectively; with a median age of 66 years. Two hundred twenty-nine (46%) of 499 patients developed CNS metastases-39% at diagnosis and 61% over the course of disease. CNS metastases were managed with surgery with or without whole-brain radiotherapy (WBRT; 13%) WBRT alone (73%), stereotactic radiosurgery with or without WBRT (5%), or no CNS-directed therapy (9%). The median time from the development of CNS metastases diagnosis to death was 9.1 months. CNS-negative patients used less HRU versus patients that were CNS-positive in the 9 months preceding death or last follow-up-in the average number of clinic visits (8.53 v 12.71, respectively; P < .001), hospitalizations (0.43 v 0.76, respectively; P < .001), CNS imaging investigations (0.52 v 2.65, respectively; P < .001), emergency room visits (0.03 v 0.14, respectively; P = .001), palliative care unit admission (8% v 10%, respectively; P = .64), and hospice admission (3% v 19%, respectively; P < .001).

CONCLUSION

The incidence of CNS metastases in patients with EGFRm is high and associated with increased HRU. Prevention or delay of CNS metastases with newer systemic therapy options may translate into lower resource utilization.

[Research Progress of Immunotherapy for Brain Metastases in Patients with Drive Gene Negative NSCLC]

脑转移是非小细胞肺癌（non-small cell lung cancer, NSCLC）常见的转移部位和导致死亡的主要原因。酪氨酸激酶抑制剂（tyrosine kinase inhibitor, TKI）改善了驱动基因阳性NSCLC患者的生存，同时也为驱动基因阳性NSCLC脑转移患者带来了福音，然而对于驱动基因阴性脑转移NSCLC仍然缺少有效的治疗手段。近年来，免疫靶向治疗取得突破性进展，成为晚期NSCLC，尤其是驱动基因阴性患者一、二线治疗选择。免疫靶向治疗在NSCLC的特殊人群——脑转移患者尤其是驱动基因阴性患者中发挥怎样的作用已经成为研究者关注的焦点。本文将总结免疫靶向治疗在NSCLC脑转移尤其是驱动基因阴性患者中的研究进展，分析现有研究的局限和未来面临的挑战。

Osimertinib for EGFR-Mutant Lung Cancer with Brain Metastases: Results from a Single-Center Retrospective Study

INTRODUCTION

Osimertinib is a third-generation tyrosine kinase inhibitor, initially approved for epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) with T790M acquired resistance, and now approved in the first-line setting. However, data supporting the use of osimertinib in untreated brain metastases are limited, although it has established central nervous system (CNS) activity. Our study compares the clinical outcomes of patients experiencing progressing brain metastases treated with cranial irradiation and osimertinib with those treated with osimertinib alone.

METHODS

Forty patients who were treated with osimertinib at the Stanford Cancer Center from November 2015 to December 2016 were identified by searching an electronic medical record database. Eleven patients had progressing brain metastases and did not receive radiation (group A), 9 patients had progressing brain metastases and received radiation when starting osimertinib (group B), and 20 patients had stable brain metastases at the time of initiating osimertinib (group C). Patient and disease characteristics, radiographic responses, and survival outcomes were evaluated retrospectively for the three groups.

RESULTS

The CNS response rate was 32.3%. Median time to treatment failure (TTF), overall progression-free survival (PFS), and overall survival (OS) were 10.0 months (95% confidence interval [CI], 4.5-11.8), 8.8 months (95% CI, 6.2-12.1), and 16.2 months, respectively. Median TTF was 15.1 months for group A (95% CI, 1.7-28.5), 7.7 months for group B (95% CI, 0-15.5), and 10.7 months for group C (95% CI, 9.0-12.5). The median PFS was 8.8 months for group A (95% CI, 4.3-13.4), not reached for group B, and 8.4 months for group C (95% CI, 5.6-11.1). The median OS was not reached for group A and C, and was 16.2 months for group B. There was no apparent difference in TTF, PFS, or OS between the three groups.

CONCLUSION

Receiving radiation prior to starting osimertinib for patients with progressing brain metastases did not prolong TTF, PFS, or OS in our series. To minimize the risks of radiation-related toxicity, delaying radiation could be considered for some patients with EGFR-mutant NSCLC with brain metastases who initially respond to osimertinib in the second-line setting.

IMPLICATIONS FOR PRACTICE

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor recently approved for the first-line treatment of EGFR-mutant non-small cell lung cancer. Although it appears to have central nervous system (CNS) activity, most clinical trials have excluded patients with untreated, progressing brain metastases. This study included patients with stable and progressing CNS metastases treated with osimertinib and found no apparent differences in median time to treatment failure, time to progression, and overall survival in patients who received osimertinib alone compared with those who received osimertinib and radiosurgery. This may support a clinician's decision to defer radiation for selected patients with untreated brain metastases who are candidates for osimertinib therapy.

Non-small cell lung cancer leptomeningeal metastases treated with intrathecal therapy plus osimertinib and temozolomide and whole-brain radiation therapy: a case report

RATIONALE

Leptomeningeal metastasis (LM) is an important cause of mortality in patients with non-small cell lung cancer (NSCLC). As the symptoms of LM and its early clinical manifestations are nonspecific, early diagnosis of LM is difficult. However, there are few treatment options for LM, which leads to a poor prognosis; thus, increased clinical attention is necessary. The effects of most systemic chemotherapies on metastatic brain tumors (brain metastases and LMs) are limited as they cannot pass the blood-brain barrier; therefore, whole-brain radiation therapy is a therapeutic option. Osimertinib is a potent and irreversible third-generation oral epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). It binds to EGFR with high affinity when the EGFR T790M mutation is present together with sensitizing mutations. The clinical efficacy of osimertinib in NSCLC patients carrying the T790M mutation has been demonstrated in clinical trial NCT02468661. Intrathecal injection of chemotherapeutic drugs can be directed to a specific lesion. Temozolomide is one such drug, and its effect has been confirmed.

PATIENT AND INTERVENTIONS

We treated a 38-year-old patient with NSCLC who carried the EGFR L858R mutation. We administered a combination of oral osimertinib and oral temozolomide plus an intrathecal injection of cytarabine and whole-brain radiation therapy for symptomatic multiple brain metastases.

OUTCOMES

The patient showed a marked response to this combination therapy. To date (after ~18 months), no recurrence or new lesions have been observed and he is asymptomatic. His disease-free survival surpasses that achieved with any monotherapy for LM.

LESSONS

This is the first report to demonstrate the response to combination therapy in an NSCLC patient with LM. These findings indicate the potential utility of chemotherapy combined with radiotherapy combined with targeted therapy combined with local treatment, as each treatment acts via a different mechanism, enhancing their therapeutic effects.

Impact of number versus location of metastases on survival in stage IV M1b non-small cell lung cancer

BACKGROUND

To assess the impact of location versus number of extra-pulmonary metastatic sites (EPMS) on survival in stage IV non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Retrospective analysis was conducted on patients diagnosed during 1999-2013 with stage IV, M1b (AJCC 7th edition) NSCLC using the large, institutional Glans-Look Database, which contains patient demographic, clinical, pathological, treatment, and outcome information. We assessed the impact of location and number of EPMS and identified correlates of overall survival using the Kaplan-Meier method and Cox regression.

RESULTS

We identified a total of 2065 NSCLC patients with EPMS. Median age was 67 (IQR 58-75) years, 52% were men, and 78% were current or former smokers. 60% had one EPMS, and 40% had two or more EPMS. Among those with only one EPMS, most frequent organ involvement included bone (40%), brain (32%), and liver (13%). Median overall survival (mOS) was worst in those with liver metastasis and best in those with adrenal metastasis (2.0 vs. 5.2 months, p = 0.015). However, outcomes based on site of organ involvement were not significantly different in multivariable analysis. Compared to patients with one EPMS, individuals with two or more EPMS experienced worse outcomes (mOS ≤ 2.9 vs. 3.9 months, p < 0.001), and were associated with worse prognosis in Cox regression analysis (HR 1.5, 95% CI 1.3-1.7, p < 0.001).

CONCLUSIONS

Number rather than location of EPMS is a prognostic factor in patients with stage IV M1b NSCLC. This information is relevant for accurate prognostication, stratification of participants in future clinical trials, and timely and appropriate advanced care planning.

A consensus on the role of osimertinib in non-small cell lung cancer from the AME Lung Cancer Collaborative Group

The first- and second-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have brought substantial clinical benefit to patients with advanced non-small cell lung cancer (NSCLC) and sensitizing EGFR mutation. However, acquired resistance is inevitable since the vast majority of patients experience disease relapse within ~1-2 years. Osimertinib is a novel irreversible, covalent third-generation EGFR-TKI and potent inhibitor of EGFR T790M mutation, the most common mechanism of acquired resistance to first-generation EGFR-TKIs. Several trials have consistently demonstrated the superior clinical activity and safety of osimertinib in patients with advanced NSCLC and acquired EGFR T790M mutation after treatment with a first-generation EGFR-TKI. Recently, the efficacy of osimertinib in a first-line setting was demonstrated to be clearly superior to standard-first line treatment in patients with EGFR-mutant NSCLC regardless of T790M mutation status. Nevertheless, this advance, several unresolved issues of osimertinib should be emphasized including the molecular mechanisms of acquired resistance to osimertinib, the feasibility of testing EGFR T790M mutation from plasma circulating tumor DNA, its efficacy to patients with central nervous system (CNS) metastases or exon 20 mutations, its combination with other therapeutic strategies such as immune checkpoint inhibitors and its role in adjuvant therapy.

Medical Treatment Options for Patients with Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer Suffering from Brain Metastases and/or Leptomeningeal Disease

Brain metastases and/or leptomeningeal disease (LMD) with associated central nervous system (CNS) metastases are known complications of advanced epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC). It is important, therefore, to assess the activity of EGFR tyrosine kinase inhibitors (TKIs) versus such CNS complications. This review explores the literature reporting the intracranial activity of EGFR TKIs, and finds that there is evidence for varying efficacy of the approved agents, erlotinib, gefitinib, afatinib, and osimertinib in patients with CNS metastases. Other EGFR TKIs in development, such as AZD3759, may have a future role as therapeutic options in this setting. Emerging evidence indicates that the second- and third-generation EGFR TKIs, afatinib and osimertinib, effectively penetrate the blood-brain barrier, and therefore represent viable treatment options for CNS lesions, and can reduce the risk of CNS progression. These agents should therefore be considered as first-line treatment options in patients with EGFR mutation-positive NSCLC who have brain metastases and/or LMD. While there are currently no prospective data comparing the intracranial efficacy of second- and third-generation EGFR TKIs in this setting, CNS activity and protection offered by different EGFR TKIs should be an additional consideration when making decisions about the optimal sequence of treatment with EGFR TKIs in order to maximize survival benefit in individual patients.

Systemic Therapy of Lung Cancer CNS Metastases Using Molecularly Targeted Agents and Immune Checkpoint Inhibitors

Central nervous system (CNS) metastases most commonly arise from lung cancer, with the majority of patients affected during their disease course. The prognosis for patients with untreated brain metastases is poor, with surgical resection and/or radiotherapy as classic therapeutic options. However, the value of systemic therapy in the management of CNS metastases from lung cancer is growing. Novel targeted agents for the treatment of non-small cell lung cancer (NSCLC) have demonstrated activity in treating patients with CNS involvement, and are potential alternatives to radiation and surgery. These agents include anaplastic lymphoma kinase (ALK) inhibitors such as alectinib, crizotinib, ceritinib, lorlatinib, and others; epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, including the recently developed third-generation inhibitor osimertinib, and even immune checkpoint inhibitors such as nivolumab, pembrolizumab, and atezolizumab. This review summarizes current activity of systemic agents in the management of CNS metastases from NSCLC, as well as potential mechanisms of action of these small and large molecules.

Biomarkers predict enhanced clinical outcomes with afatinib versus methotrexate in patients with second-line recurrent and/or metastatic head and neck cancer

Background

In the phase III LUX-Head & Neck 1 (LUX-H&N1) trial, second-line afatinib significantly improved progression-free survival (PFS) versus methotrexate in patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). Here, we evaluated association of prespecified biomarkers with efficacy outcomes in LUX-H&N1.

Patients and methods

Randomized patients with R/M HNSCC and progression following ≥2 cycles of platinum therapy received afatinib (40 mg/day) or methotrexate (40 mg/m2/week). Tumor/serum samples were collected at study entry for patients who volunteered for inclusion in biomarker analyses. Tumor biomarkers, including p16 (prespecified subgroup; all tumor subsites), EGFR, HER2, HER3, c-MET and PTEN, were assessed using tissue microarray cores and slides; serum protein was evaluated using the VeriStrat® test. Biomarkers were correlated with efficacy outcomes.

Results

Of 483 randomized patients, 326 (67%) were included in the biomarker analyses; baseline characteristics were consistent with the overall study population. Median PFS favored afatinib over methotrexate in patients with p16-negative [2.7 versus 1.6 months; HR 0.70 (95% CI 0.50-0.97)], EGFR-amplified [2.8 versus 1.5 months; HR 0.53 (0.33-0.85)], HER3-low [2.8 versus 1.8 months; HR 0.57 (0.37-0.88)], and PTEN-high [1.6 versus 1.4 months; HR 0.55 (0.29-1.05)] tumors. Afatinib also improved PFS in combined subsets of patients with p16-negative and EGFR-amplified tumors [2.7 versus 1.5 months; HR 0.47 (0.28-0.80)], and patients with p16-negative tumors who were EGFR therapy-naïve [4.0 versus 2.4 months; HR 0.55 (0.31-0.98)]. PFS was improved in afatinib-treated patients who were VeriStrat 'Good' versus 'Poor' [2.7 versus 1.5 months; HR 0.71 (0.49-0.94)], but no treatment interaction was observed. Afatinib improved tumor response versus methotrexate in all subsets analyzed except for those with p16-positive disease (n = 35).

Conclusions

Subgroups of HNSCC patients who may achieve increased benefit from afatinib were identified based on prespecified tumor biomarkers (p16-negative, EGFR-amplified, HER3-low, PTEN-high). Future studies are warranted to validate these findings.

Clinical trial registration

NCT01345682.

Targeted DNA sequencing of non-small cell lung cancer identifies mutations associated with brain metastases

Introduction

This study explores the hypothesis that dominant molecular oncogenes in non-small cell lung cancer (NSCLC) are associated with metastatic spread to the brain.

Methods

NSCLC patient groups with no evidence of metastasis, with metastatic disease to a non-CNS site, who developed brain metastasis after diagnosis, and patients with simultaneous diagnosis of NSCLC and metastatic brain lesions were studied using targeted sequencing.

Results

In patients with brain metastasis versus those without, only 2 variants (one each in BCL6 and NOTHC2) were identified that occurred in ≥ 4 NSCLC of patients with brain metastases but ≤ 1 of the NSCLC samples without brain metastases. At the gene level, 20 genes were found to have unique variants in more than 33% of the patients with brain metastases. When analyzed at the patient level, these 20 genes formed the basis of a predictive test to discriminate those with brain metastasis. Further analysis showed that PI3K/AKT signaling is altered in both the primary and metastases of NSCLC patients with brain lesions.

Conclusion

While no single variant was associated with brain metastasis, this study describes a potential gene panel for the identification of patients at risk and implicates PI3K/AKT signaling as a therapeutic target.

Association of molecular status and metastatic organs at diagnosis in patients with stage IV non-squamous non-small cell lung cancer

OBJECTIVES

Biological predisposition for specific metastatic organs might differ between molecular subgroups of lung cancer. We aimed to assess the association between molecular status and metastatic organs at diagnosis in a nationwide stage IV non-squamous non-small cell lung cancer ((ns)-NSCLC) cohort.

METHODS

All ns-NSCLC from 2013 that were stage IV at diagnosis were identified from the Netherlands Cancer Registry, which records information on metastatic organs at diagnosis. Tumors were matched to the Dutch Pathology Registry (PALGA) from which data on molecular status established in routine practice was extracted. Four molecular subgroups (EGFR+, KRAS+, ALK+, triple-negative) were identified. For each metastatic organ, proportions of tumors metastasized to this organ were, per molecular subgroup, compared to triple-negative tumors by multivariable logistic regression analyses (adjusted odds ratios (OR) with 95% confidence intervals (CI)), taking clinicopathological variables into account.

RESULTS

160 EGFR+ (exon 19 del, exon 21 L858R), 784 KRAS+, 42 ALK+, and 1008 triple-negative tumors were identified. Most frequent metastatic organs were the bone (34%), pleura (24%), lung (23%), and brain (22%). Compared to triple-negatives, EGFR+ tumors had more often metastases to the bone (31.5 vs 53.8%; OR 2.55 (95% CI 1.80-3.62)) and pleura (24.1 vs 37.5%; OR 2.06 (1.42-2.98)), and less often to the brain (22.0 vs 12.5%; OR 0.53 (0.32-0.88)) and adrenal glands (19.1 vs 7.5%; OR 0.46 (0.28-0.75)). Compared to triple-negatives, KRAS+ and ALK+ tumors had at diagnosis metastasized more often to the lung (20.3 vs 26.7%; OR 1.40 (1.12-1.76)) and the liver (13.1 vs 23.8%; OR 2.07 (1.00-4.32)), respectively.

CONCLUSION

NSCLC molecular status was associated with metastatic pattern at diagnosis. 54% of stage IV EGFR+ ns-NSCLC patients had bone metastases at diagnosis. These observational results are hypothesis generating, and call for a prospective study where EGFR+ patients are screened for bone metastases, and treated to prevent skeletal related events.

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.

Analyzing EGFR mutations and their association with clinicopathological characteristics and prognosis of patients with lung adenocarcinoma

Epidermal growth factor receptor (EGFR) is an important gene in the development of lung adenocarcinoma. However, there is controversy regarding the association between EGFR mutations and survival time of patients with lung adenocarcinoma. In the present study, tissue specimens and clinical data were collected from 219 patients with lung adenocarcinoma who had not undergone prior radiotherapy or chemotherapy. EGFR mutations were detected using a fluorescence polymerase chain reaction method, and the association between EGFR mutations and clinicopathological characteristics was analyzed. Overall survival (OS) curves were constructed using the Kaplan-Meier method and the influence of clinicopathological characteristics on OS was analyzed using the Cox regression model. The EGFR mutation rate was 50.7%, and the most common mutations were the L858R substitution mutation in exon 21 (L858R; 54.9%) and the deletion mutation in exon 19 (19-Del; 36%). The presence of EGFR mutations varied significantly with sex, smoking history, T stage, vascular invasion and adenocarcinoma subtypes (P<0.05). The survival time was significantly longer for female, young (<60 years-old), non-smokers or patients exhibiting EGFR mutations (G719X, 19-Del, L858R and L861Q). The survival time was also significantly longer for patients with a 19-Del mutation, early stage tumors, tyrosine kinase inhibitors targeted therapy-treated patients, for those not exhibiting nerve or vascular invasion, and for those without disease recurrence (P<0.05). Multivariate analysis revealed that tumor pathological Tumor-Node-Metastasis (pTNM) stage, nerve invasion, vascular invasion, EGFR mutation and the 19-Del mutation were independent predictors (P<0.05). Therefore, tumor pTNM stage, nerve invasion, vascular invasion and EGFR mutation status, particularly that of 19-Del, were independent prognostic factors for patients with lung adenocarcinoma.

Role of Epidermal Growth Factor Receptor (EGFR) Inhibitors and Radiation in the Management of Brain Metastases from EGFR Mutant Lung Cancers

The growth of genotype-directed targeted therapies, such as inhibitors of the epidermal growth factor receptor (EGFR), has revolutionized treatment for some patients with oncogene-addicted lung cancer. However, as systemic control for these patients has improved, brain metastases remain an important source of morbidity and mortality. Traditional treatment for brain metastases has been radiotherapy, either whole-brain radiation or stereotactic radiosurgery. The growing availability of drugs that can cross the blood-brain barrier and have activity in the central nervous system (CNS) has led to many studies investigating whether targeted therapy can be used in combination with or in lieu of radiation. In this review, we summarize the key literature about the incidence and nature of EGFR-mutant brain metastases (EGFR BMs), the data about the activity of EGFR inhibitors in the CNS, and whether they can be used as front-line therapy for brain metastases. Although initial use of tyrosine kinase inhibitors for EGFR BMs can often be an effective treatment strategy, multidisciplinary evaluation is critical, and prospective studies are needed to clarify which patients may benefit from early radiotherapy.

IMPLICATIONS FOR PRACTICE

Management of brain metastases in epidermal growth factor receptor (EGFR) mutant lung cancer is a common clinical problem. The question of whether to start initial therapy with an EGFR inhibitor or radiotherapy (either whole-brain radiotherapy or stereotactic radiosurgery) is controversial. The development of novel EGFR inhibitors with enhanced central nervous system (CNS) penetration is an important advance in the treatment of CNS disease. Multidisciplinary evaluation and evaluation of extracranial disease status are critical to choosing the best treatment option for each patient.

Lung cancer in never smokers from the Princess Margaret Cancer Centre

Introduction

Lung cancer in never smokers represents a distinct epidemiological, clinical, and molecular entity.

Results

Most 712 never smoking lung cancer patients were female (72%) with a median age at diagnosis of 62.2 years (18–94). Caucasians (46%), East Asians (42%), adenocarcinoma histology (87%) and presentation with metastatic disease at diagnosis (59%) were common. Of 515 patients with available archival tissue, the most common identified single mutations were EGFR (52.2%), followed by ALK (7.5%), KRAS (2.3%), TP53 (1.3%), ERBB2 (1%), BRAF (0.4%), PIK3CA (0.4%), SMAD4 (0.4%), CTNNB1 (0.2%), AKT1 (0.2%), and NRAS (0.2%); 8% tumors had multiple mutations, while 25.8% had none identified. Median overall survival (mOS) was 42.2 months (mo) for the entire cohort. Patients with mutations in their tumors had significantly better mOS (69.5 mo) when compared to those without (31.0 mo) (HR = 0.59; 95% CI: 0.44–0.79; p < 0.001). Earlier stage (p < 0.001), adenocarcinoma histology (p = 0.012), good performance status (p < 0.001) and use of targeted therapy (p < 0.001) were each independently associated with longer survival. Patients with ALK-translocation-positive tumours have significantly longer OS compared to those without any mutations (p = 0.0029) and to those with other and null mutations (p = 0.022).

Conclusions

Lung cancer in never smokers represents a distinct clinical and molecular entity characterized by a high incidence of targetable mutations and long survival.

Methods

We analyzed retrospectively the data from electronic patient records of never smokers diagnosed with lung cancer treated at the Princess Margaret Cancer Centre (Toronto) between 1988–2015 to characterize demographic and clinical features, pathology, molecular profile (using hotspot or targeted sequencing panels), treatment and survival.

COL5A1 may contribute the metastasis of lung adenocarcinoma

BACKGROUND

Lung cancer leads to the largest number of cancer-related deaths worldwide and is usually accompanied with metastasis which is the primary cause of those death and correlated with poor prognosis. However, the mechanism of lung cancer metastasis is still lack of definition.

METHODS

We compared the primary lung adenocarcinoma (AD) and its metastasis tissues induced by overexpression of Kras^G12D and inactivation of P53 in mouse lungs by analyzing GSE40222 about the differentially expressed genes (DEGs), pathways and hub genes. And human lung AD databases are used to verify the conversed changes of identified key gene and then followed functional studies are performed to explore the functions of key gene.

RESULTS

We identified 165 genes differentially expressed in lung AD metastasis compared to primary AD. Pathway analysis identified 649 GO biological processes and 8 KEGG pathways, such as ECM-receptor interaction. Biological network interaction identified the hub genes during lung adenocarcinoma metastasis, such as the up-regulated COL5A1, a novel gene in AD metastasis. We found it's also increased in human AD and advanced stage. Knockdown of COL5A1 in human AD metastatic cells inhibited cell growth and invasion, and induced cell apoptosis. Notably, higher expression of COL5A1 was observed in the lung AD patients with recurrence and short survive.

CONCLUSION

By analyzing mouse lung AD and its metastases, we identified the potential key genes and pathways regulating lung AD metastasis, such as COL5A1. The following analysis of COL5A1 in human AD database and cells explores its functions, holding the implications of target therapy in AD metastasis and also providing more clues for future studies.

A retrospective analysis in patients with EGFR-mutant lung adenocarcinoma: is EGFR mutation associated with a higher incidence of brain metastasis?

Lung adenocarcinomas are more commonly associated with brain metastases (BM). Epidermal growth factor receptor (EGFR) mutations have been demonstrated to be both predictive and prognostic for patients with lung adenocarcinoma. We aimed to explore the potential association between EGFR mutation and the risk of BM in pulmonary adenocarcinoma patients. Data of 234 patients from 2007 to 2014 were retrospectively reviewed. A total of 108 patients had EGFR mutations in the entire cohort. Among them, 76 patients developed BM during their disease course. The incidence of BM was statistically higher in patients with EGFR mutations both at initial diagnosis (P=0.014) and at last follow-up (P<0.001). Multivariate logistic regression analysis revealed that EGFR mutation significantly increased the risk of BM at initial diagnosis (OR=2.515, P=0.022). In patients without BM at initial diagnosis, the accumulative rate of subsequent BM was significantly higher with EGFR mutations (P=0.001). Multivariate Cox regression analysis identified EGFR mutation as the only independent risk factor for subsequent BM (HR=3.036, P=0.001). Patients with EGFR mutations demonstrated longer overall survival (OS) after BM diagnosis than patients with wild-type EGFR (P=0.028). Our data suggest that EGFR mutation is an independent predictive and prognostic risk factor for BM and a positive predictive factor for OS in patients with BM.

Influence of EGFR mutational status on metastatic behavior in non squamous non small cell lung cancer

Epidermal Growth Factor Receptor (EGFR) mutated Non Small Cell Lung Cancers (NSCLCs) are a molecularly subgroup of patients with peculiar clinic-pathological characteristics. Previous studies have suggested a possible interaction between oncogene status and metastatic behavior in non squamous NSCLCs with conflicting results. The aim of this study was to compare the different metastatic patterns, at baseline and during the course of the disease, in a cohort of 137 Caucasian patients with non-squamous NSCLC according to the EGFR mutational status and survival differences according to the different metastatic behavior. We observed unique metastatic distributions between EGFR-mutated and EGFR wild type non-squamous NSCLCs. These data support the hypothesis that tumor bio-molecular characteristics and genotype may influence the metastatic process in NSCLC and might help the development of enrichment strategies for tumor genotyping in these tumors, especially in the presence of limited tissue availability.

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.

Identifying candidates for gamma knife radiosurgery among elderly patients with brain metastases

We investigated the outcomes of gamma knife radiosurgery (GKRS) for elderly patients (≥ 65 years) with brain metastases, and identified survival-associated factors. We retrospectively analyzed data from 115 patients treated with GKRS for 1-15 brain metastases. The median patient age was 72 years; most primary tumors were pulmonary (n = 83). The mean lesion volume was 2.1 ± 4.8 mL. A mean dose of 19.3 Gy was delivered to the mean 63.9% isodose line. The median overall survival (OS) was 5.3 months (95% confidence interval [CI] 3.5-7.1). During follow-up (median, 5.1 months), 91 patients died of primary cancer progression while 1 died of unknown causes. The 6- and 12-month local control rates were 94.9 and 88.1%, respectively. On multivariate analysis, female sex (p = 0.005, hazard ratio [HR] 0.533, 95% CI 0.343-0.827) and a controlled primary tumor (p < 0.001, HR 0.328, 95% CI 0.180-0.596) were significantly favorable prognostic factors. Of non-small cell lung cancer patients with EGFR mutations, 76.5% were women (p = 0.005). The median OS of EGFR-mutant and EGFR-wildtype patients were 19.1 and 4.7 months, respectively (p = 0.080). Brain metastases < 3 mL showed better local control rates after GKRS (p = 0.005). GKRS produces favorable outcomes in women with brain metastases who are ≥ 65 years and have controlled primary tumors. Such patients are therefore suitable candidates for GKRS.

Diffusion-Weighted Imaging of Brain Metastasis from Lung Cancer: Correlation of MRI Parameters with the Histologic Type and Gene Mutation Status

BACKGROUND AND PURPOSE

Development of noninvasive imaging biomarkers indicating the histology and the gene mutation status of brain metastasis from lung cancer is important. We aimed to investigate diffusion-weighted imaging parameters as predictors of the histology and gene mutations of brain metastasis from lung cancer.

MATERIALS AND METHODS

DWI data for 74 patients with brain metastasis from lung cancer were retrospectively reviewed. The patients were first grouped according to the primary tumor histology (adenocarcinoma, small-cell lung cancer, squamous cell carcinoma), and those with adenocarcinoma were further divided into epidermal growth factor receptor (EFGR) mutation-positive and wild type groups. Sex; age; number, size, and location of brain metastasis; DWI visual scores; the minimum ADC; and the normalized ADC ratio were compared among groups using χ² and ANOVA. Multiple logistic regression analysis was performed to determine independent predictors of the EGFR mutation.

RESULTS

The minimum ADC was lower in the small-cell lung cancer group than in the other 2 groups, though the difference was not significant. Furthermore, minimum ADC and the normalized ADC ratio were significantly lower in the EGFR mutation-positive group than in the wild type group (P = .021 and .014, respectively). Multivariate analysis revealed that minimum ADC and the normalized ADC ratio were independently associated with the EGFR mutation status (P = .028 and .021, respectively).

CONCLUSIONS

Our results suggest that DWI parameters (minimum ADC and normalized ADC ratio) for the solid components of brain metastasis from lung cancer are not correlated with their histology, whereas they can predict the EGFR mutation status in brain metastasis from lung adenocarcinoma.

Systemic therapy for brain metastases

Central nervous system metastases cause grave morbidity in patients with advanced malignancies. Lung cancer, breast cancer, and melanoma are the three most common causes of brain metastases. Although the exact incidence of brain metastases is unclear, there appears to be an increasing incidence which has been attributed to longer survival, better control of systemic disease, and better imaging modalities. Until recently surgical resection of solitary or symptomatic brain metastases, and radiation therapy (either whole-brain radiation therapy or stereotactic radiation) were the mainstay of treatment for patients with brain metastases. The majority of traditional chemotherapies have shown limited activity in the central nervous system, which has been attributed to the blood-brain barrier and the molecular structure of the used agents. The discovery of driver mutations and drugs targeting these mutations has changed the treatment landscape. Several of these targeted small-molecule tyrosine kinase inhibitors do cross the blood-brain barrier and/or have shown activity in the central nervous system. Another major advance in the care of brain metastases has been the advent of new immunotherapeutic agents, for which initial studies have shown intracranial activity. In this chapter, we will review the unique challenges in the treatment of brain metastases. The pertinent clinical studies of chemotherapy in brain metastases will be discussed. The currently reported clinical trials and evidence for use of targeted therapies and immunotherapeutic agents will be emphasized.

Overview of metastatic disease of the central nervous system

In 2016, the American Society of Clinical Oncology reported that 1.7 million Americans were diagnosed with cancer; this number will rise to 2.3 million in the United States and 22 million worldwide in 2030. This rising need is being met by an explosion of new cancer therapies, including: immune checkpoint inhibitors, T-cell therapies, tumor vaccines, antiangiogenic therapies, and various targeted therapies. This armamentarium of targeted therapies has led to better systemic control of disease and longer patient overall survival (OS). The incidence of metastatic disease to the central nervous system (CNS) is rising as patients are living longer with these more effective systemic therapies. Prolonged OS allows increased time to develop CNS metastases. The CNS is also a sanctuary for metastatic tumor cells that are protected from full exposure to therapeutic concentrations of most anticancer agents by the blood-brain barrier, the tumor microenvironment, and immune system. In addition, CNS metastases often develop late in the course of the disease, so patients are frequently heavily pretreated, resulting in drug resistance. Although genomic profiling has led to more effective therapies for systemic disease, the same therapy may not be effective in treating CNS disease, not only due to failure of blood-brain barrier penetration, but from discordance between the molecular profile in systemic and CNS tumor.

Epidermal growth factor receptor mutation and pattern of brain metastasis in patients with non-small cell lung cancer

BACKGROUND/AIMS

We investigated the time taken for patients with metastatic non-small cell lung cancer (NSCLC) to develop brain metastases (BM), as well as their subsequent overall median survival following diagnosis, considering the epidermal growth factor receptor (EGFR) mutational status.

METHODS

We retrospectively investigated the medical records of 259 patients diagnosed with advanced NSCLC from January 2010 to August 2013, who were tested for EGFR mutations. The time from the diagnosis of advanced NSCLC to the development of BM and the overall median survival after BM development (BM-OS) were evaluated and compared by EGFR mutational status.

RESULTS

Sixty-seven patients (25.9%) developed BM. Synchronous BM occurred more often in patients with EGFR mutation type (MT) (n = 20, 27.4%) compared with EGFR wild type (WT) (n = 27, 14.5%, p < 0.009). The median BM-OS was significantly longer in patients with EGFR MT than in those with EGFR WT (25.7 months vs. 3.8 months, p < 0.001), and a similar trend was noticed for patients with synchronous BM (25.7 months for EGFR MT vs. 6.8 months for EGFR WT, p < 0.001). However, in patients with metachronous BM development, the difference in BM-OS between patients with EGFR MT (14.6 months) and EGFR WT (2.5 months) did not reach statistical significance (p = 0.230).

CONCLUSIONS

Synchronous BM was more common in NSCLC patients with EGFR MT than in those with EGFR WT. However, EGFR mutations were associated with significantly longer median BM-OS, especially when the brain was the first metastatic site.

AZD3759, a BBB-penetrating EGFR inhibitor for the treatment of EGFR mutant NSCLC with CNS metastases

Non-small-cell lung cancer patients with activating mutations in epidermal growth factor receptor (EGFR) respond to EGFR tyrosine kinase inhibitor (TKI) treatment. Nevertheless, patients often develop central nervous system (CNS) metastases during treatment, even when their extracranial tumors are still under control. In the absence of effective options, much higher doses of EGFR TKIs have been attempted clinically, with the goal of achieving high enough drug concentrations within the CNS. Although limited tumor responses have been observed with this approach, the toxicities outside the CNS have been too high to tolerate. We report the discovery and early clinical development of AZD3759, a selective EGFR inhibitor that can fully penetrate the blood-brain barrier (BBB), with equal free concentrations in the blood, cerebrospinal fluid, and brain tissue. Treatment with AZD3759 causes tumor regression in subcutaneous xenograft, leptomeningeal metastasis (LM), and brain metastasis (BM) lung cancer models and prevents the development of BM in nude mice. An early clinical study in patients with BM and LM treated with AZD3759 confirms its BBB-penetrant properties and antitumor activities. Our data demonstrate the potential of AZD3759 for the treatment of BM and LM and support its further clinical evaluation in larger trials.

Current progress and outcomes of clinical trials on using epidermal growth factor receptor-tyrosine kinase inhibitor therapy in non-small cell lung cancer patients with brain metastases

Non-small cell lung cancer (NSCLC) continues to be one of the major causes of cancer-related deaths worldwide, and brain metastases are the major cause of death in NSCLC patients. With recent advances in understanding the underlying molecular mechanism of NSCLC development and progression, mutations in epidermal growth factor receptor (EGFR) have been recognized as a key predictor of therapeutic sensitivity to EGFR tyrosine kinase inhibitors (TKIs). Using EGFR-TKI alone or in combination with standard treatments such as whole-brain radiotherapy and surgery has been an effective strategy for the management of brain metastasis. Particularly, a newer generation of EGFR-TKIs, including osimertinib and AZD3759, has been developed. These new EGFR-TKIs can cross the blood-brain barrier and potentially treat EGFR-TKI resistance and improve prognosis. In this article, current progress and outcomes of clinical trials on the use of EGFR-TKIs for treating NSCLC patients with brain metastasis will be reviewed.

Targeted therapy of brain metastases: latest evidence and clinical implications

Brain metastases (BM) occur in 20-40% of patients with cancer and 60-75% of patients with BM become symptomatic. Due to an aging population and advances in the treatment of primary cancers, patients are living longer and are more likely to experience complications from BM. The diagnosis of BM drastically worsens long-term survival rates, with multiple metastases being a poor prognostic factor. Until recently, the mainstay of treatment consisted of stereotactic radiosurgery (SRS), surgical resection, whole brain radiation therapy (WBRT), or a combination of these modalities. Systemic chemotherapy has been felt largely ineffective in the treatment of BM due to the presence of the blood-brain barrier (BBB), which includes efflux pumps on brain capillaries. Over the past decade however, researchers have identified therapeutic agents that are able to cross the BBB. These findings could make a multimodality treatment approach possible, consisting of surgery, radiation, immunotherapy, and targeted therapy, which could lead to better disease control in this patient population and prolong survival. In this review, we discuss present evidence on available targeted therapies and their role in the treatment of BM from primary tumors with the highest prevalence of central nervous system (CNS) involvement, specifically non-small cell lung cancer (NSCLC), breast cancer melanoma, and renal cell carcinoma.

An individualized gene expression signature for prediction of lung adenocarcinoma metastases

Our laboratory previously reported an individual‐level signature consisting of nine gene pairs, named 9‐GPS. This signature was developed by training on microarray expression data and validated using three independent integrated microarray data sets, with samples of stage I non‐small‐cell lung cancer after complete surgical resection. In this study, we first validated the cross‐platform robustness of 9‐GPS by demonstrating that 9‐GPS could significantly stratify the overall survival of 213 stage I lung adenocarcinoma (LUAD) patients detected with RNA‐sequencing platform in The Cancer Genome Atlas (TCGA; log‐rank P = 0.0318, C‐index = 0.55). Applying 9‐GPS to all the 423 stage I‐IV LUAD samples in TCGA, the predicted high‐risk samples were significantly enriched with clinically diagnosed metastatic samples (Fisher's exact test, P = 0.0015). We further modified the voting rule of 9‐GPS and found that the modified 9‐GPS had a better performance in predicting metastasis states (Fisher's exact test, P < 0.0001). With the aid of the modified 9‐GPS for reclassifying the metastasis states of patients with LUAD, the reclassified metastatic samples presented clearer transcriptional and genomic characteristics compared to the reclassified nonmetastatic samples. Finally, regulator network analysis identified TP53 and IRF1 with frequent genomic aberrations in the reclassified metastatic samples, indicating their key roles in driving tumor metastasis. In conclusion, 9‐GPS is a robust signature for identifying early‐stage LUAD patients with potential occult metastasis. This occult metastasis prediction was associated with clear transcriptional and genomic characteristics as well as the clinical diagnoses.

Development of metastatic brain disease involves progression through lung metastases in EGFR mutated non-small cell lung cancer

Lung cancer is often classified by the presence of oncogenic drivers, such as epidermal growth factor receptor (EGFR), rather than patterns of anatomical distribution. While metastatic spread may seem a random and unpredictable process, we explored the possibility of using its quantifiable nature as a measure of describing and comparing different subsets of disease. We constructed a database of 664 non-small cell lung cancer (NSCLC) patients treated at the University of Southern California Norris Comprehensive Cancer Center and the Los Angeles County Medical Center. Markov mathematical modeling was employed to assess metastatic sites in a spatiotemporal manner through every time point in progression of disease. Our findings identified a preferential pattern of primary lung disease progressing through lung metastases to the brain amongst EGFR mutated (EGFR m) NSCLC patients, with exon 19 deletions or exon 21 L858R mutations, as compared to EGFR wild type (EGFR wt). The brain was classified as an anatomic "sponge", with a higher ratio of incoming to outgoing spread, for EGFR m NSCLC. Bone metastases were more commonly identified in EGFR wt patients. Our study supports a link between the anatomical and molecular characterization of lung metastatic cancer. Improved understanding of the differential biology that drives discordant patterns of anatomic spread, based on genotype specific profiling, has the potential to improve personalized oncologic care.

Novel Treatment Strategies for Brain Metastases in Non-small-cell Lung Cancer

OPINION STATEMENT

Brain metastases are common in patients with non-small cell lung cancer (NSCLC), and due to associated poor prognosis, this field is an important area of need for the development of innovative medical therapies. Therapies including local approaches through surgical intervention and/or radiation and evolving systemic therapies have led to improvements in the treatment of brain metastases in patients with lung cancer. Strategies that consider applying advanced radiation techniques to minimize toxicity, intervening early with effective systemic therapies to spare radiation/surgery, testing radiosensitization combinations, and developing drug penetrant molecules have and will continue to define new practice patterns. We believe that in carefully considered asymptomatic patients, first-line systemic therapy may be considered before radiation therapy and small-molecule targeted therapy may provide an opportunity to defer radiation therapy for recurrence or progression of disease. The next several years in oncology drug development will see the reporting on of brain penetrant molecules in oncogene-defined non-small cell lung cancer. Ongoing studies will evaluate immunotherapies in patients with brain metastases with associated endpoints. We hope that continued drug development and carefully designed clinical trials may afford an opportunity to improve the lives of patients with brain metastases.

Evaluation on efficacy and safety of the addition of X-knife therapy to gefitinib in NSCLC patients with symptomatic brain metastases

Background

Stereotactic radiosurgery (SRS) is a widely used therapy for brain metastases(BMs) in Non-small cell lung cancer(NSCLC). However, its role in symptomatic patients with EGFR mutation remains unclear. We have retrospectively reviewed the clinical data of patients with symptomatic BMs whom received SRS as a salvage approach and concurrent gifitinib therapy.

Methods

Seven patients with primary NSCLC, symptomatic BMs, and EGFR mutation were identified in a retrospective review of patients treated with SRS using X-knife at Guangdong 999 Brain Hospital between 1 January 2012 and 31 August 2014. The median follow-up of these patients was 16 months. Image fusion technique was used to determine cumulative doses to targeted lesions, whole brain, and critical brain structures. Toxicities and complications were identified by clinical records.

Results

SRS(X-knife) was selected to be performed on seven patients (two males and five females) diagnosed with NSCLC and EGFR mutation due to the presence of encephaledema, compression of ventricles, or other complications. Neurological symptoms (such as paresis, aphasia, sensory and visual disturbances) were not present in any patients before or after SRS treatment, and the postoperative Karnofsky performance status(KPS) was improved in all patients. Median overall survival(OS) was 16 months and median progression free survival(PFS) was 10 months.

Conclusions

The improvement of KPS and survival were reliable by SRS(X-knife) with concurrent gifitinib therapy in NSCLC patients with symptomatic BMs, and EGFR mutation. Given the small sample size, further prospective studies with a greater number of patients are warranted to confirm our results.

A Neuro-oncologist's Perspective on Management of Brain Metastases in Patients with EGFR Mutant Non-small Cell Lung Cancer

Management of non-small cell lung cancer (NSCLC) with brain metastasis (BrM) has been revolutionized by identification of molecular subsets that have targetable oncogenes. Historically, survival for NSCLC with symptomatic BrM was weeks to months. Now, many patients are surviving years with limited data to guide treatment decisions. Tumors with activating mutations in epidermal growth factor receptor (EGFRact+) have a higher incidence of BrM, but a longer overall survival. The high response rate of both systemic and BrM EGFRact+ NSCLC to tyrosine kinase inhibitors (TKIs) has led to the rapid incorporation of new therapies but is outpacing evidence-based decisions for BrM in NSCLC. While whole brain radiation therapy (WBRT) was the foundation of management of BrM, extended survival raises concerns for the subacute and late effects radiotherapy. We favor the use of TKIs and delaying the use of WBRT when able. At inevitable disease progression, we consider alternative dosing schedules to increase CNS penetration (such as pulse dosing of erlotinib) or advance to next generation TKI if available. We utilize local control options of surgery or stereotactic radiosurgery (SRS) for symptomatic accessible lesions based on size and edema. At progression despite available TKIs, we use pemetrexed-based platinum doublet chemotherapy or immunotherapy if the tumor has high expression of PDL-1. We reserve the use of WBRT for patients with more than 10 BrM and progression despite TKI and conventional chemotherapy, if performance status is appropriate.

Correlation between EGFR mutation status and the incidence of brain metastases in patients with non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Numerous studies have been performed to investigate the correlation between epidermal growth factor receptor (EGFR) mutation status and the incidence of brain metastases (BMs) in patients with non-small cell lung cancer (NSCLC), however, the outcomes were inconsistent. Thus, we performed this study to establish the role of EGFR mutation status in BMs.

METHODS

Electronic databases PubMed, Embase, Cochrane Library, CBM, WanFang, CNKI were searched to identify relevant trials. The primary endpoint was the incidence of BMs in EGFR mutations or wild type NSCLC and the secondary endpoint was overall survival calculated from the BMs emerging (BMOS).

RESULTS

Twenty-two studies incorporating 8,152 participants were eligible. EGFR mutations group possessed a significantly higher risk of BMs (OR =1.99; 95% CI, 1.59-2.48; P=0.000) than EGFR wild type group. In the stratified analysis, compared with EGFR wild type group, EGFR mutations group had a significant higher incidence (OR =2.01; 95% CI, 1.56-2.59; P=0.000) of subsequent BMs while only a trend of increasing the incidence of initial BMs (OR =1.38; 95% CI, 0.98-1.94; P=0.066). Moreover, exon 19 deletion had a trend of increasing the incidence of BMs than exon 21 mutation (OR =1.44; 95% CI, 0.77-2.68; P=0.252). Compared with EGFR wild type group, EGFR mutations group possessed a prolonged overall BMOS (HR =0.68; 95% CI, 0.47-0.98; P=0.038) and a longer BMOS in initial BMs (HR =0.50; 95% CI, 0.31-0.80; P=0.004) but no significant difference in NSCLC with subsequent BMs (HR =0.95; 95% CI, 0.42-2.15; P=0.901).

CONCLUSIONS

Patients with EGFR mutations were more susceptible to develop into BMs than those with EGFR wild type, especially during the course of disease.

Can we define the optimal sequence of epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of epidermal growth factor receptor-mutant nonsmall cell lung cancer?

PURPOSE OF REVIEW

The most common mechanism of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is acquisition of the T790M gatekeeper mutation. Third-generation EGFR TKIs irreversibly inhibit EGFR mutants (EGFRm), especially T790M, while sparing wild-type EGFR. There are several third-generation EGFR TKIs under development, including osimertinib, CO-1686 (rociletinib), HM61713 (olmutinib), ASP8273, and EGF816. These third-generation EGFR TKIs have shown promising efficacy with favorable toxicity profiles in the management of advanced nonsmall cell lung cancer (NSCLC) with an acquired T790M mutation (EGFR). In the present review, we will discuss the evolving treatment landscape of EGFRm NSCLC.

RECENT FINDINGS

The LUX-Lung 7 study demonstrated superior progression-free survival, time-to-treatment failure, and objective response rate with afatinib versus gefitinib, but no significant overall survival improvement in TKI-naïve EGFRm NSCLC patients. In EGFRm NSCLC patients harboring T790M after treatment with first-generation or second-generation EGFR TKIs, third-generation EGFR TKIs showed robust efficacy with tolerable toxicity. The updated results of phase I studies have demonstrated encouraging activity of first-line osimertinib in patients with EGFRm NSCLC.

SUMMARY

Following progression with first-generation or second-generation EGFR TKIs, osimertinib was recently approved for the treatment of EGFR NSCLC. Encouraging early results with osimertinib have sparked interest in first-line treatment of EGFRm NSCLC, and head-to-head comparison studies of third-generation versus first-generation EGFR TKIs are being developed.

The Current Role of Whole Brain Radiation Therapy in Non-Small Cell Lung Cancer Patients

The incidence of brain metastases has increased in patients with NSCLC as a result of better systemic disease control and advances in imaging modalities. Whole brain radiotherapy (WBRT) has been the mainstay treatment of multiple symptomatic brain metastases for years. A number of recent publications have questioned its place in the absence of a survival and quality of life benefit and the possible risk for long-term neurotoxicity. Omission or deferral of WBRT and strategies consisting of stereotactic radiosurgery or delivery of systemic therapies alone are being proposed more and more. However, critical analysis of the literature shows that WBRT still has relevant indications in well-selected patients. Within this review, we discuss the place of WBRT in the modern management of patients with NSCLC.

The effectiveness of EGFR-TKIs against brain metastases in EGFR mutation-positive non-small-cell lung cancer

Brain metastases are usual in non-small-cell lung cancer (NSCLC) with poor prognosis and few available therapeutic options. This retrospective study aims to evaluate the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) against brain metastases from NSCLC harboring activating EGFR mutation. A total of 148 patients with brain metastases from EGFR mutation-positive NSCLC were analyzed retrospectively. The patients were orally given gefitinib (250 mg) or erlotinib (150 mg) once a day until intracranial disease progression, death, or intolerable side effects. A survival analysis was done using the Kaplan–Meier analysis and log-rank test. Objective response rate and disease control rate within brain lesions were 36.5% and 87.2%, respectively, with a median progression-free survival (PFS) and overall survival (OS) of 11.2 months (95% confidence interval [CI], 10.1–12.3) and 13.6 months (95% CI, 12.3–14.9), respectively. The patients’ characteristics were not statistically associated with PFS and OS. EGFR-TKIs showed promising antitumor activity against brain metastases in NSCLC patients with activating EGFR mutation and might be the treatment choice in this clinical setting.

Efficacy of Second-line Tyrosine Kinase Inhibitors in the Treatment of Metastatic Advanced Non-small-cell Lung Cancer Harboring Exon 19 and 21 EGFR Mutations

Background: Although superior clinical benefits of first-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in the treatment of advanced non-small-cell lung cancer (NSCLC) had been reported with different sensitivity, the sensitivity of second-line TKIs in NSCLC patients with different EFGR mutations was unknown. The purpose of this study is to investigate the clinical outcome of second-line EGFR-TKIs in the treatment of NSCLC patients according to different EGFR genotypes.

Methods: The treatment outcomes of 166 NSCLC patients with different EGFR mutations treated by second-line TKIs were retrospectively reviewed. The efficacy was evaluated with Pearson chi-square or Fisher's exact tests, Log-rank test and Cox proportional hazards model.

Results: The disease control rate (DCR) and objective response rate (ORR) of enrolled NSCLC patients were 77.7% and 11.4%, respectively. The exon 19 deletion group had a significantly longer median progression-free survival (PFS) (6.7 vs. 4.5 months, P=0.002) and overall survival (OS) (13.7 vs. 11.7 months, P=0.02) compared with the exon 19 L858R mutation group for NSCLC patients, as well for patients with brain metastasis [PFS: (6.7 vs. 3.9 months, p<0.001), OS: (13.7 vs. 7.9 months, p=0.006)]. No significant difference on PFS and OS was observed between exon 19 deletion and L858R mutation group for patients with bone metastasis. EGFR genotype and ECOG PS were independent predictors of PFS. Never smoking, exon 19 deletion, EGOC PS (0-1) and no brain metastasis were correlated with longer OS. No significant difference on side effect between exon 19 and 21 mutation group was observed.

Conclusions: NSCLC patients harboring exon 19 deletion achieved better PFS and OS than those with L858R mutation, indicating that EGFR mutation is a significant prognostic factor for advanced NSCLC patients with and without brain metastasis receiving second-line EGFR-TKIs treatment.

Pulsatile Erlotinib in EGFR-Positive Non-Small-Cell Lung Cancer Patients With Leptomeningeal and Brain Metastases: Review of the Literature

Patients with epidermal growth factor receptor (EGFR)-positive (EGFR⁺) non-small-cell lung cancer (NSCLC) show improved response rates when treated with tyrosine kinase inhibitors (TKIs) such as erlotinib. However, standard daily dosing of erlotinib often does not reach therapeutic concentrations within the cerebrospinal fluid (CSF), resulting in progression of central nervous system (CNS) disease. Intermittent, high-dose administration of erlotinib reaches therapeutic concentrations within the CSF and is well tolerated in patients. Experience with "pulsatile" dosing, however, is limited. We review the literature on the pharmacology and clinical outcomes of pulsatile erlotinib in the treatment of EGFR⁺ NSCLC with brain and leptomeningeal metastases, and include available data on the use of next-generation TKIs in CNS progression. We also provide our institution's experience with patients treated with pulsatile erlotinib for CNS metastasis, and propose clinical criteria for its use. Pulsatile erlotinib is a reasonable alternative in EGFR⁺ patients with new or worsening CNS disease, without evidence of systemic progression, and without confirmed T790M resistance mutations within the CNS.

Role of epidermal growth factor receptor in lung cancer and targeted therapies

Lung cancer is the foremost cause of cancer-related deaths world-wide. Both, the major forms of lung cancer, Non-small cell lung cancer (NSCLC) and Small cell lung cancers (SCLC), have responded effectively to chemo-, radiation and adjuvant-therapies. Tumor removal through surgery also appeared as a good therapeutic strategy. However, these therapies demonstrated unfavourable side-effects, and hence novel drugs targeting lung cancer emerged essential. Activation of epidermal growth factor receptor (EGFR)-tyrosine kinases is a key reason for lung cancer progression. Two important strategies that have attenuated lung cancers were through treatments with EGFR-tyrosine kinase-inhibitors, erlotinib and gefitinib, or EGFR-neutralizing antibodies, cetuximab and bevacizumab. A major advantage with erlotinib and gefitinib was their role in second and third-line treatments following chemotherapies. Phase II/III clinical trials showed that combinatorial treatment of tyrosine kinase (TK)-inhibitors with chemotherapeutics, such as docetaxel and pemetrexed, caused significant improvements in progression-free survival and overall survival.Phase I and II clinical studies also revealed that combination of tyrosine kinase-inhibitors with the EGFR-targeted antibodies was an effective approach for treating lung cancer. However, patients having T790M-mutations within EGFR gene were resistant to erlotinib and gefitinib. Alternatively, another second-generation EGFR-tyrosine kinase-inhibitor, afatinib, that could circumvent the problem of drug resistance has been developed as lung cancer therapy. The current review focuses on the role of EGFR in lung cancer progression and apprises about the EGFR-targeted therapies. The review also informs on the adverse side-effects of these therapies and enlightens the need for safer therapeutic regimens to eradicate this dreaded disease.

Predictive factors of early distant brain failure after gamma knife radiosurgery alone in patients with brain metastases of non-small-cell lung cancer

The objective of this study was to elucidate the predictive factors for early distant brain failure in patients with brain metastases of non-small-cell lung cancer (NSCLC) who were treated with gamma knife radiosurgery (GKRS) without previous whole-brain radiotherapy (WBRT) or surgery. We retrospectively reviewed clinical and imaging data of 459 patients with brain metastases of NSCLC who underwent GKRS from June 2008 to December 2013. The primary end-point was early distant brain failure, defined as the detection of newly developed metastatic lesions on magnetic resonance imaging (MRI) 3 months after GKRS. Factors such as tumor pathology subtype, concurrent systemic chemotherapy, epidermal growth factor receptor (EGFR) mutation status, use of EGFR tyrosine kinase inhibitors (TKIs), systemic disease status, presence of a metastatic lesion only in delayed MRI, and volume and number of metastases were analyzed. There were no statistically significant differences with respect to pathologic subtype, concurrent systemic chemotherapy, EGFR mutation, and early distant brain failure. Patients treated with EGFR-TKIs (p = 0.004), with a stable systemic disease status (p = 0.028) and 3 or fewer brain lesions (p = 0.000) experienced a significantly lower incidence of early distant brain failure. This study suggests that GKRS alone could be considered for patients treated with EGFR-TKIs who have a stable systemic disease status and 3 or fewer brain lesions. WBRT should be considered for other patients.

The impact of tumor biology on survival and response to radiation therapy among patients with non-small cell lung cancer brain metastases

PURPOSE

To investigate the natural history and response to radiation therapy among ALK-rearranged, EGFR-mutated, wild-type adenocarcinoma, and squamous cell non-small cell lung cancer (NSCLC) brain metastases.

METHODS AND MATERIALS

Patients with NSCLC brain metastasis diagnosed from 1989 through 2014 at a single tertiary-care institution were included. The primary outcome was overall survival, whereas secondary outcomes included local failure, distant intracranial failure, and radiation necrosis. Cox proportional hazards regression was used to model overall survival; multivariate competing risks regression was used to model secondary outcomes.

RESULTS

Within the study period, 1920 patients presented with 6312 brain metastases. Squamous histology was associated with poorer median survival compared with adenocarcinomas (5.4 vs 8.8 months, P < .01). Median survival was greatest among ALK+ patients (49.2 months), followed by EGFR+ (20.3 months), and wild-type adenocarcinomas (10.0 months, P < .01). Treatment with estimated glomerular filtration rate inhibitors (hazard ratio [HR], 0.66; P < .01) and vascular endothelial growth factor antibodies (HR, 0.65; P < .01) increased survival independent of mutational status. Among 2056 lesions treated with stereotactic radiosurgery, the 12-month cumulative incidence of local failure was significantly greater among squamous cell carcinomas relative to adenocarcinomas (15% vs 10%, HR, 1.26; P = .04). Patients with ALK+ metastases experienced higher rates of local failure (10%; HR, 2.00; P = .05), distant failure (39%; HR, 2.94; P < .01), and radiation necrosis (18%; HR, 5.77; P < .01), whereas EGFR+ patients experienced the lowest rates of local failure (5%; HR, 0.46; P = .04) and distant failure (3%; HR, 0.13; P = .04).

CONCLUSIONS

Advances in precision medicine have increased survival among select patients with NSCLC. In the present investigation, ALK+ and EGFR+ status were associated with improved survival. However, patients with ALK+ metastases have poor intracranial control relative to EGFR+ metastases, possibly because of limited intracranial penetration of crizotinib compared with estimated glomerular filtration rate inhibitors. Future investigations are warranted to determine the optimal management of ALK+ brain metastases with the introduction of second-generation ALK inhibitors.