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

The relationship between cerebrospinal fluid metastasis and gene mutations in non-small-cell lung cancer patients

OBJECTIVE

The aim of this study was to use cerebrospinal fluid (CSF) cytology to give undiagnosed patients admitted to the hospital with severe neurological symptoms and without any anti-tumor treatment history a definitive diagnosis. Further, the aim was to explore the relationship between the frequency of gene mutations and mortality on the incidence of CSF metastasis in advanced non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

30 patients diagnosed with NSCLC through CSF cytology were retrospectively analyzed. We analyzed 30 CSF metastasis patients and a control group of 20 advanced NSCLC patients without CSF metastasis.

RESULTS

30 patients were diagnosed with CSF metastasis using CSF cytology and immunocytopathology. The frequencies of EGFR mutations and ALK fusion in the CSF metastasis group were higher than they were in the non-CSF metastasis group (80% and 50% respectively, P<0.05). The incidence of CSF metastasis with gene mutations was higher than it was with wild-type genes (70.6% and 37.5%, P<0.05), OR 4.0 (95% CI 1.14~13.99). The median survival time of the CSF metastasis group was 4.8 months (95% CI 4.2~5.3). However, the median survival time in the non-CSF metastasis group was 9.2 months (95% CI 3.3~15.1). The mortality of the CSF metastasis group (n=13, 43.3%) was significantly higher than it was in the non-CSF metastasis group (n=6, 30%).

CONCLUSIONS

CSF metastasis in NSCLC patients has a higher frequency of gene mutations and mortality. EGFR mutation and ALK fusion patients have a higher incidence of CSF metastasis. EGFR mutations and ALK fusion may promote CSF metastasis and may be a predictor of prognosis in NSCLC patients.

Management of CNS metastases in patients with EGFR mutation-positive NSCLC

Central nervous system (CNS) metastases are a frequent and severe complication associated with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). The first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) have shown considerable efficacy in EGFR-mutated NSCLC. However, their limited potential to cross the blood-brain barrier (BBB) renders them less effective in the management of CNS metastases in NSCLC. Osimertinib, a third-generation irreversible EGFR-TKI with good potential to cross the BBB, has shown significant clinical activity and acceptable safety profile in patients with EGFR-positive NSCLC brain and leptomeningeal metastases. The progression-free survival (PFS) of up to 15.2 months in CNS metastases patients in the FLAURA trial and the CNS objective response rates (ORRs) of 54% and 43% in the AURA/AURA2 and BLOOM trials, respectively, have established the role of osimertinib in patients with NSCLC with CNS metastases. The AURA3 trial also reported a PFS of 8.5 months and overall ORR of 71%. These data have supported osimertinib to be recognized as a "preferred" first-line treatment for EGFR-positive metastatic NSCLC by the National Comprehensive Cancer Network (NCCN). With limited treatment options available, upfront administration of osimertinib in patients with NSCLC irrespective of EGFR T790M and CNS metastases may improve the overall response rate and potentially reduce the adverse effects of radiotherapy. Our review focuses on the management of EGFR-mutated NSCLC CNS metastases in the context of recent NCCN guidelines.

Brain metastases from non-small cell lung cancer with EGFR or ALK mutations: A systematic review and meta-analysis of multidisciplinary approaches

BACKGROUND AND PURPOSE

To analyze outcomes of non-small cell lung cancer (NSCLC) patients with brain metastases harboring EGFR or ALK mutations and examine for differences between tyrosine kinase inhibitors (TKIs) alone, radiotherapy (RT) alone (either whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS)), or combined TKIs and RT.

MATERIALS AND METHODS

Thirty studies were identified.

PATIENTS

with brain metastases from NSCLC.

INTERVENTION

initial TKIs alone with optional salvage RT, RT alone, or TKIs and RT.

CONTROL

wild-type NSCLC and TKIs alone for mutational and treatment analysis, respectively.

OUTCOMES

overall survival (OS) and intracranial progression-free survival (PFS).

SETTING

studies with mutation information.

RESULTS

A total of 2649 patients were included. Patients with ALK and EGFR mutations had significantly higher median OS (48.5 months, p < 0.0001; and 20.9 months; p = 0.0006, respectively) compared to wild-type patients (9.9 months). Similar median OS was noted between TKIs and RT (28.3 months), RT alone (32.2 months; p = 0.22), or TKIs alone (23.9 months; p = 0.2). Patients treated with TKIs and RT had higher median PFS (18.6 months; p = 0.06) compared to TKIs alone (13.6 months) with no difference between TKIs and RT vs. RT alone (16.9 months; p = 0.72). No PFS difference was found between WBRT and TKI (23.2 months; p = 0.72) vs. WBRT alone (24 months) or SRS and TKI (16.7 months; p = 0.56) vs. SRS alone (13.6 months).

CONCLUSION

NSCLC patients with brain metastases harboring EGFR or ALK mutations have superior OS compared to wild-type patients. No PFS or OS benefit was found with the addition of TKIs to RT.

Metastases to the central nervous system: Molecular basis and clinical considerations

BACKGROUND

Metastatic tumors are the most common malignancies of the central nervous system (CNS) in adults. CNS metastases are associated with unfavorable prognosis, high morbidity and mortality. Lung cancer is the most common source of brain metastases, followed by breast cancer and melanoma. Rising incidence is primarily due to improvements in systemic control of primary malignancies, prolonged survival and advances in cancer detection.

PURPOSE

To provide an overview of the metastatic cascade and the role of angiogenesis, neuroinflammation, metabolic adaptations, and clinical details about brain metastases from different primary tumors.

METHODS

A review of the literature on brain metastases was conducted, focusing on the pathophysiology and clinical aspects of the disease. PubMed was used to search for relevant articles published from January 1975 through December 2019 using the keywords brain metabolism, brain metastasis, metastatic cascade, molecular mechanisms, incidence, risk factors, and prognosis. 146 articles met the criteria and were included in this review.

DISCUSSION

Some primary tumors have a higher tendency to metastasize to the CNS. Establishing a suitable metastatic microenvironment is important in maintaining tumor cell growth and survival. Magnetic resonance imaging (MRI) is a widely used tool for diagnosis and treatment monitoring. Available treatments include surgery, radiotherapy, stereotactic radiosurgery, chemotherapy, immunotherapy, and systemic targeted therapies.

CONCLUSIONS

Prevention of metastases to the CNS remains a difficult challenge. Advances in screening of high-risk patients and future development of novel treatments may improve patient outcomes.

Metastasis Patterns and Prognosis of Octogenarians with NSCLC: A Population-based Study

Non-small cell lung cancer (NSCLC) is the most common cancer and the leading cause of cancer-related deaths worldwide. Age at diagnosis of advanced NSCLC is much older, but studies describing the practice patterns for octogenarians with distant metastasis NSCLC are limited. A retrospective, population-based study using national representative data from the Surveillance, Epidemiology, and End Results (SEER) program was conducted to evaluate 34 882 NSCLC patients with extrathoracic metastases from 2010 to 2013. Patients were classified into three groups (older group: ≥80 yrs, middle-aged group: 60-79 yrs, and younger group: ≤59 yrs). The role of different age at diagnosis of NSCLC in metastasis patterns was investigated, and survival of different age groups of metastatic NSCLC was assessed. The analysis revealed that older patients were more likely to only have bone or liver metastasis (p< 0.001), but less likely to have brain only metastasis (p<0.001) and multiple metastatic sites (p< 0.001) than other two groups. Age at diagnosis was an independent risk factor for different metastasis types. Older group had the worst overall survival (p<0.001) and cancer-specific survival (p<0.001). Furthermore, older age patients with only bone metastasis had the best cancer specific survival (p<0.05) while younger patients with only brain metastasis had the best prognosis (p<0.001). Over 60% octogenarians with metastatic NSCLC did not receive anti-cancer therapy and had the highest rate of cancer deaths among all patients. Our results may help clinicians make positive decisions regarding personalized treatment of metastatic NSCLC in the elderly.

Micropapillary pattern is associated with the development of brain metastases and the reduction of survival time in EGFR-mutation lung adenocarcinoma patients with surgery

OBJECTIVE

The role of micropapillary pattern (MIP) in EGFR-mutated NSCLC patients with brain metastases (BM) after complete surgical resection still remains unclear. Therefore, a retrospective study was conducted to evaluate the role of MIP in those patients.

METHODS

This study included 332 stage I-III patients with EGFR-mutant lung adenocarcinoma and complete resection. Patients were classified in four groups: the MIP-positive patients without BM development, the MIP-negative patients without BM development, the MIP-positive patients with BM development and the MIP-negative patients with BM development. Intracranial disease-free survival (iDFS), systemic disease-free survival (DFS) and overall survival (OS) were evaluated.

RESULTS

The median OS in the whole group was 70 months. The patients with MIP show inferior DFS (13 months vs. 22 months; P < 0.001) and OS (56 months vs. 74 months; P < 0.001). Furthermore, BM development was more likely to be found in patients with MIP (P = 0.001). In addition, the MIP-positive patients showed a significantly shorter iDFS compared with MIP-negative patients (14.5 months vs. 26 months; P < 0.001). Furthermore, the MIP-positive patients had significantly inferior iDFS in both BM as first line development groups (13 months vs. 19 months; P < 0.001) and BM as non-first line development groups (18 months vs. 33 months; P = 0.007).

CONCLUSIONS

MIP was related to the earlier recurrence and shortened survival time. In addition, MIP was an independent poor prognostic factor for the increase of BM rate and the shortened time of BM development after surgery.

Frequency and outcomes of brain metastases in patients with HER2-mutant lung cancers

BACKGROUND

Mutations in human epidermal growth factor receptor 2 (HER2; also known as ERBB2) are found in approximately 2% of lung adenocarcinomas. The frequency and clinical course of brain metastases in this oncogenic subset are ill defined.

METHODS

Baseline and subsequent development of brain metastases was evaluated in consecutive patients with HER2-mutant (n = 98), epidermal growth factor receptor (EGFR)-mutant (n = 200), and KRAS-mutant lung cancers (n = 200).

RESULTS

At metastatic diagnosis, the odds ratio (ORs) for brain metastases was similar for patients whose tumors harbored HER2 mutations (19%) in comparison with patients with KRAS mutations (24%; OR for HER2 vs KRAS, 0.7; P = .33) but lower compared to patients with EGFR mutations (31%; OR for HER2 vs EGFR, 0.5; P = .03). Patients with lung cancer and HER2 mutations developed more brain metastases on treatment than patients with KRAS mutations (28% vs 8%; hazard ratio [HR], 5.2; P < .001) and trended more than patients with EGFR mutations (28% vs 16%; HR, 1.7; P = .06). Patients with HER2 YVMA mutations also developed more brain metastases on treatment than patients with KRAS mutations (HR, 5.9; P < .001). The median overall survival (OS) was shorter for patients with HER2-mutant (1.6 years; P < .001) or KRAS-mutant lung cancers (1.1 years; P < .001) than patients with EGFR-mutant lung cancers (3.0 years). Brain metastases occurred in 47% of patients with HER2-mutant lung cancers, which imparted shorter OS (HR, 2.7; P < .001).

CONCLUSIONS

These data provide a framework for brain imaging surveillance in patients with HER2-mutant lung cancers and underpin the need to develop HER2-targeted agents with central nervous system activity.

Brain MRI imaging characteristics predict treatment response and outcome in patients with de novo brain metastasis of EGFR-mutated NSCLC

Patients with non-small cell lung cancer (NSCLC) and de novo brain metastasis (BM) have poor prognosis. We aim to investigate the characteristic of brain magnetic resonance (MR) imaging and the association with the treatment response of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for lung cancer with BM.EGFR-mutated NSCLC patients with BM from October 2013 to December 2017 in a tertiary referral center were retrospectively analyzed. Patient's age, sex, cell type, EGFR mutation status, treatment, and characteristics of BM were collected. Survival analysis was performed using Kaplan-Meier method. The efficacy of different EGFR-TKIs were also analyzed.Among the 257 eligible patients, 144 patients with Exon 19 deletion or Exon 21 L858R were included for analysis. The erlotinib group had the best progression free survival (PFS) (median PFS 13 months, P = .04). The overall survival (OS) revealed no significant difference between three EGFR-TKI groups. Brain MR imaging features including tumor necrosis, rim enhancement and specific tumor locations (frontal lobe, putamen or cerebellum) were factors associated with poor prognosis. Patients with poor prognostic imaging features, the high-risk group, who received erlotinib had the best PFS (median PFS 12 months, P < .001). However, the OS revealed no significant difference between 3 EGFR-TKI groups. The low risk group patients had similar PFS and OS treated with three different EGFR-TKIs.In NSCLC patients with common EGFR mutation and de novo BM, those with poor prognostic brain MR characteristics, erlotinib provided better PFS than afatinib or gefitinib.

Combination of Whole-Brain Radiotherapy with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Improves Overall Survival in EGFR-Mutated Non-Small Cell Lung Cancer Patients with Brain Metastases

Brain metastases (BM) cause morbidity and mortality in patients with non-small cell lung cancer (NSCLC). The use of upfront epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and withholding of whole-brain radiation therapy (WBRT) is controversial. We aim to investigate the impact of WBRT on overall survival (OS). After screening 1384 patients, a total of 141 EGFR-mutated patients with NSCLC and BM were enrolled. All patients received EGFR-TKIs between 2011 and 2015. Ninety-four patients (66.7 %) were treated with WBRT (TKI + WBRT group). With a median follow-up of 20.3 months (95% confidence interval (CI), 16.9-23.7), the median OS after the diagnosis of BM was 14.3 months (95% CI, 9.5 to 18.3) in the TKI + WBRT group and 2.3 months (95% CI, 2 to 2.6) in the TKI alone group. On multivariate analysis, WBRT (p < 0.001), female, surgery to primary lung tumor, and surgery to BM were associated with improved OS. The 1-year OS rate was longer in the TKI+WBRT group than that in the TKI alone group (81.9% vs 59.6%, p = 0.002). In conclusion, this is the first study to demonstrate the negative survival impact from the omission of WBRT in patients with EGFR-mutant NSCLC.

Epidermal Growth Factor Receptor (EGFR)-Tyrosine Kinase Inhibitors (TKIs) Combined with Chemotherapy Delay Brain Metastasis in Patients with EGFR-Mutant Lung Adenocarcinoma

BACKGROUND

Whether epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) combined with chemotherapy can delay the occurrence of brain metastasis (BM) is unclear.

OBJECTIVE

This retrospective study aimed to evaluate whether EGFR-TKIs combined with chemotherapy can delay BM and decrease the incidence of BM as initial progression.

PATIENTS AND METHODS

The data of 100 patients with EGFR-mutant advanced lung adenocarcinoma were retrospectively reviewed. The patients had no BM at initial diagnosis, and BM occurred during the treatment. Patients received EGFR-TKI only or EGFR-TKI combined with chemotherapy. Intracranial progression-free survival (iPFS), systemic progression-free survival (PFS), and overall survival (OS) were evaluated.

RESULTS

The overall median OS was 39 months (95% confidence interval (CI), 35.6-42.4 months). The median OS of EGFR-TKI combined with chemotherapy and EGFR-TKI only are 41 months (95% CI 35.5-46.5 months) and 39 months (95% CI 36.8-41.2 months), respectively. Patients in the combination treatment group had longer PFS (16 vs. 10 months; P = 0.030) and iPFS (21 vs. 14 months; P = 0.026). Further, as initial progression, fewer patients developed BM in the combined treatment group compared with the EGFR-TKI-only group (30.6% vs. 52.9%, P = 0.002) with a hazard ratio of 0.64 (95% CI 0.43-0.96). After controlling for significant covariables in a multivariable model, the different treatment strategies were independently associated with improved iPFS.

CONCLUSIONS

In this retrospective analysis, EGFR-TKIs combined with chemotherapy could improve PFS. Further, the combined treatment could delay BM occurrence and decrease the incidence of BM as initial progression.

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

•

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

•

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

•

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.

Osimertinib Regresses an EGFR-Mutant Cisplatinum- Resistant Lung Adenocarcinoma Growing in the Brain in Nude Mice

The goal of the present study was to determine the efficacy of osimertinib (AZD9291), a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor for the treatment of aggressive EGFR-mutant non-small cell lung cancer (NSCLC), compared to cisplatinum (CDDP) + pemetrexed (PEM). The NSCLC cell line PC-9 expressing green fluorescence protein (PC-9-GFP) was implanted in the brain of nude mice and was treated with CDDP + PEM or AZD9291. Tumors were observed by non-invasive fluorescence imaging. AZD9291 treatment caused tumor regression in contrast to CDDP + PEM which had only a slight inhibitory effect. These results suggest that AZD9291 is a promising clinical option for NSCLC patients with brain metastasis.

The role of EGFR mutation as a prognostic factor in survival after diagnosis of brain metastasis in non-small cell lung cancer: a systematic review and meta-analysis

Background

The brain is a common site for metastasis in non-small-cell lung cancer (NSCLC). This study was designed to evaluate the relationship between the mutational of the epidermal growth factor receptor (EGFR) and overall survival (OS) in NSCLC patients with brain metastases.

Methods

Searches were performed in PubMed, EmBase, and the Cochrane Library to identify studies evaluating the association of EGFR mutation with OS in NSCLC patients through September 2017.

Results

4373 NSCLC patients with brain metastases in 18 studies were involved. Mutated EGFR associated with significantly improved OS compared with wild type. Subgroup analyses suggested that this relationship persisted in studies conducted in Eastern, with retrospective design, with sample size ≥500, mean age of patients ≥65.0 years, percentage male < 50.0%, percentage of patients receiving tyrosine kinase inhibitor ≥30.0%. Finally, although significant publication bias was observed using the Egger test, the results were not changed after adjustment using the trim and fill method.

Conclusions

This meta-analysis suggests that EGFR mutation is an important predictive factor linked to improved OS for NSCLC patients with brain metastases. It can serve as a useful index in the prognostic assessment of NSCLC patients with brain metastases.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5331-z) contains supplementary material, which is available to authorized users.

EGFR first- and second-generation TKIs-there is still place for them in EGFR-mutant NSCLC patients

Identification of epidermal growth factor receptor (EGFR) as a molecular target has radically changed the treatment of metastatic non-small cell lung cancer (NSCLC) from standard chemotherapy to personalized, targeted therapy. First-, second- and third-generation EGFR tyrosine kinase inhibitors (TKIs) are now available for the treatment of EGFR-mutant NSCLC patients. This review will focus on the clinical development of first- and second-generation EGFR TKIs. We will emphasize on essential points like the head-to-head comparison among EGFR TKIs, their activity on brain metastases, mechanisms of resistance, as well as their combination with anti-angiogenic compounds, other targeted therapies, or immunotherapy. The efficacy of first- and second-generation EGFR TKIs in early-stage EGFR-mutant NSCLC will be also finally reviewed.

Incidence of brain metastasis in lung adenocarcinoma at initial diagnosis on the basis of stage and genetic alterations

OBJECTIVE

Patients with lung adenocarcinoma (ADC) are at higher risk of the development of brain metastasis (BM), and genetic alterations are associated with BM.

PATIENTS AND METHODS

A total of 598 patients with lung ADC in our institution between January 2014 and December 2014 were reviewed retrospectively. We evaluated the incidence of BM by stage and genetic alterations.

RESULTS

Of the 598 patients, 97 (16.2%) had BM, which occurred across all stages. The incidence of BM showed a tendency to increase as the stage increased (p < 0.001, trend test). Although patients with EGFR mutations had BM across all stages, those with ALK or K- mutations had BM only in stage III and IV diseases. Regardless of types of mutations, the incidence of BM showed a tendency to increase as the T or N staging increased (p < 0.001 for each of EGFR, ALK, and K-RAS mutations, trend test). Whereas BM incidence showed a tendency to increase as the M staging increased in patients with EGFR-mutant lung ADC (p < 0.001, trend test), there was no linear trend between M staging and ALK (p = 0.469, trend test) or K-RAS mutations (p = 0.066, trend test). After adjusting covariables, EGFR mutations were associated with BM in never-smokers (adjusted OR = 2.07, 95% CI = 1.02-4.34) and K-RAS mutations were risk factors for BM in males (adjusted OR = 3.86, 95% CI = 1.01-14.43).

CONCLUSIONS

BM occurred in approximately 16% of lung ADC patients, including 3% with stage I diseases. Whereas EGFR-mutant lung ADC had BM across all stages, ALK- or K-RAS-mutant lung ADC had BM only in advanced stages. EGFR mutations were risk factors for BM among never-smokers and K-RAS mutations were risk factors among males.

Upfront Cranial Radiotherapy vs. EGFR Tyrosine Kinase Inhibitors Alone for the Treatment of Brain Metastases From Non-small-cell Lung Cancer: A Meta-Analysis of 1465 Patients

Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is revolutionizing the management of brain metastases (BMs). This study was to explore the value of upfront cranial radiotherapy (RT) in EGFR-mutated non-small cell lung cancer (NSCLC) with BMs compared with EGFR-TKIs alone. Methods: We searched all topic-related comparative articles in public databases (MEDLINE, EMBASE, Cochrane Library, and Web of Science) and conference proceedings. Outcomes of interest were intracranial objective response rate (ORR), overall survival (OS), and intracranial progression-free survival (PFS). Statistical analyses were calculated using Review Manager 5.3 software. Results: Thirteen comparative studies that included a total of 1,456 patients were eligible. Upfront brain RT had significantly higher OS (HR = 0.78, 95% CI = 0.65-0.93, P = 0.005) than EGFR-TKI alone. Upfront RT plus TKI had superior OS (HR = 0.71, 95% CI = 0.58-0.86, P = 0.0005) and intracranial PFS (HR = 0.69, 95% CI = 0.49-0.99, P = 0.04). The pooled data favored upfront whole brain RT (WBRT) plus TKI in terms of intracranial PFS (HR = 0.64, 95% CI = 0.48-0.85, P = 0.002) and OS (HR = 0.75, 95% CI = 0.57-1, P = 0.05). Upfront stereotactic radiosurgery (SRS) was associated with better OS (HR = 0.37, 95% CI = 0.26-0.54, P < 0.00001). Similar results were observed when analysis was restricted to the use of erlotinib or geftinib. Conclusions: The upfront use of brain RT seemed critical, especially for SRS. Upfront administration of upfront WBRT plus EGFR-TKI had better survival outcomes and seemed superior to EGFR-TKI alone.

Epidermal Growth Factor Receptor Mutation Detection in Cerebrospinal Fluid of Lung Adenocarcinoma Patients with Leptomeningeal Metastasis

BACKGROUND

Epidermal growth factor receptor (EGFR) mutations are associated with leptomeningeal metastases (LM) of nonsmall cell lung cancer and sensitivity to tyrosine kinase inhibitor (TKI) treatment. Owing to the difficulty of obtaining carcinomatous meningeal tissue for analysis, cerebrospinal fluid (CSF) might be an alternative.

OBJECTIVE

To investigate the EGFR mutation detection in the CSF of lung adenocarcinoma patients with LM.

METHODS

Twenty-five lung adenocarcinoma patients with LM diagnosed by CSF cytology were retrospectively evaluated. The results of EGFR mutation detection in CSF, the treatment plan, and clinical outcome information were recorded.

RESULTS

Nineteen patients had a known EGFR status in their primary tumors. Twenty patients received EGFR mutation analysis in CSF after LM diagnosis and 14 of them with a known EGFR mutation status of both primary tumors and CSF. Ten (71.4%) had the same EGFR gene status. In primary tumors, no T790M mutations were detected, whereas in CSF, 2 L858R cases and 1 19del case had T790M mutations at the same time. The detection rate of T790M mutations in CSF was 18.1% (2 of 11) in all cases with EGFR-sensitive mutations in the primary lesion.

CONCLUSIONS

EGFR mutation detection in CSF of lung adenocarcinoma patients with LM might be an alternative when leptomeningeal biopsy cannot be applied and may help to guide TKI treatments.

[Association between EGFR, ALK and KRAS Gene Status and Synchronous Distant Organ Metastasis in Non-small Cell Lung Cancer]

肺癌是我国恶性肿瘤的首位死亡疾病，据统计大约57%的肺癌患者就诊时已经出现了远处转移，临床预后较差。抗肺癌转移是当前治疗晚期转移性肺癌的新方向和思路。既往研究表明肿瘤的生物学改变在一定程度上能够影响肿瘤的转移行为和侵袭扩散模式，而目前的基础及临床研究尚未阐明导致肺癌相关信号转导途径中发生特异性器官转移的分子机制，有关驱动基因突变与器官转移之间相关性的研究也较为罕见。本篇综述旨在对近几年有关非小细胞肺癌表皮生长因子受体（epidermal growth factor receptor, EGFR）、间变性淋巴瘤激酶（anaplastic lymphoma kinase, ALK）、Kristen鼠肉瘤病毒原癌基因同源体（V-Ki-ras2 Kirsten rat sarcoma viral oncogene homologue, KRAS）驱动基因表达的特点以及与转移器官分布之间相关性的文献进行小结。

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

Introduction

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

Methods

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

Results

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

Conclusions

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