Epidermal growth factor receptor mutations in needle biopsy/aspiration samples predict response to gefitinib therapy and survival of patients with advanced nonsmall cell lung cancer

Germline EGFR mutations in lung cancer (Review)

Lung cancer is the leading cause of cancer-related death and familial lung cancer is a potential contributing factor. Epidermal growth factor receptor (EGFR) mutations are important events in carcinogenesis. The present study summarized the common germline mutations of EGFR, including T790M, V843I, R776H and P848L, and provided detailed information regarding each mutation site and potential treatment strategies. Individuals with germline mutations may develop lung cancer upon exposure to environmental stimuli such as smoking, air pollution or radiological contamination, or due to the occurrence of another somatic mutation. The present study recommends regular physical examinations as well as population-wide germline mutation screening for early detection and diagnosis of lung cancer.

Different treatment efficacies and T790M acquisition of EGFR-TKIs on NSCLC patients with variable Del-19 subtypes of EGFR

EGFR exon 19 deletion (Del-19) comprises multiple advanced NSCLC subtypes. EGFR-tyrosine kinase inhibitor (TKI) efficacy and T790M acquisition in various Del-19 subtypes is unknown. We prospectively collected tissue samples from patients harboring NSCLC with Del-19 between 2006 and 2020. We evaluated EGFR-TKI treatment effectiveness among the different Del-19 subtypes. We collected 1391 NSCLC samples from 892 patients with Del-19, and the most common subtype was del E746-A750 (67.5%). 741 patients had taken first- or second-generation EGFR-TKIs. There were no significant differences in response rates between patients with different Del-19 subtypes (P = .630). Patients with indel E746 had the longest median PFS (14.6 months), but those with non-LRE deletions had the shortest PFS (8.9 months; P = .002). For OS analysis, patients with indel E746 also had the longest OS (34.1 months), but those with non-LRE deletions had the shortest OS (21.1 months; P = .046). Patients with different Del-19 subtypes showed no significant differences in the T790M acquisition rates (P = .443). Among the 151 patients with acquired T790M who received third-generation EGFR-TKIs, the Del-19 subtype was not associated with different RR and PFS. In vitro cellular viability and activation of the EGFR pathway analysis were consistent with the clinical findings. In conclusion, compared with del E746-A750, indel E746 was associated with longer PFS and OS, but the non-LRE subtype was correlated with shorter survival prognosis. There were no significant differences in the acquired T790M rate and treatment effectiveness of subsequent third-generation EGFR-TKIs between various Del-19 subgroups.

Gamma Knife Radiosurgery Irradiation of Surgical Cavity of Brain Metastases: Factor Analysis and Gene Mutations

(1) Background: Surgical resection for the removal of brain metastases often fails to prevent tumor recurrence within the surgical cavity; hence, researchers are divided as to the benefits of radiation treatment following surgical resection. This retrospective study assessed the effects of post-operative stereotactic radiosurgery (SRS) on local tumor control and overall survival. (2) Methods: This study examined the demographics, original tumor characteristics, and surgical outcomes of 97 patients who underwent Gamma Knife Radiosurgery (GKRS) treatment (103 brain metastases). Kaplan-Meier plots and Cox regression were used to correlate clinical features to tumor control and overall survival. (3) Results: The overall tumor control rate was 75.0% and overall 12-month survival was 89.6%. Tumor control rates in the radiation group versus the non-radiation group were as follows: 12 months (83.1% vs. 57.7%) and 24 months (66.1% vs. 50.5%). During the 2-year follow-up period after SRS, the intracranial response rate was higher in the post-craniotomy radiation group than in the non-radiation group (p = 0.027). Cox regression multivariate analysis determined that post-craniotomy irradiation of the surgical cavity is predictive of tumor control (p = 0.035). However, EGFR mutation was not predictive of overall survival or tumor control. (4) Conclusions: Irradiating the surgical cavity after surgery can enhance local tumor control; however, it does not have a significant effect on overall survival.

Correlation of EGFR G873R mutation with prognosis of docetaxel in non-small cell lung cancer

Background

Clinical features of epidermal growth factor receptor (EGFR) mutations have been commonly recognized in variant cancers. The role of EGFR mutations in non-small cell lung cancer (NSCLC) has spurred research and drug development efforts. However, there are still mutations that have not been widely reported, and their influences on NSCLC have not been fully elucidated; EGFR G873R mutation is just one of them. The aim of this study was to investigate the correlation between EGFR G873R mutation and the prognosis of chemotherapy in NSCLC.

Methods

A total of 54 patients with NSCLC were enrolled in this study. Immunohistochemical staining was used to detect the expression of EGFR. A DNA extraction kit (GeneRead DNA FFPE Kit) was used to extract total DNA from resected cancer tissues. Genomic DNA targets were amplified by polymerase chain reaction (PCR), and then the amplicons were purified and sequenced. Statistical methods were performed to detect the relationship between EGFR G873R mutation and various clinicopathological features and the effect of EGFR G873R mutation on the prognosis of chemotherapy.

Results

EGFR G873R mutation did not show statistical significance, with EGFR high expression identified in 30 cases (P>0.05). Patients with EGFR G873R mutation had a significantly favorable prognosis of docetaxel (P=0.032), and for patients treated with docetaxel, EGFR G873R mutation was significantly correlated with better 5-year disease-free survival (DFS; P=0.026) and overall survival (OS; P=0.026). However, there was no statistical significance found between EGFR G873R mutation and the prognosis of vinorelbine (P>0.05), and for patients treated with vinorelbine, EGFR G873R mutation had no statistical significance with 5-year DFS (P>0.05) and OS (P>0.05).

Conclusions

EGFR G873R mutation was remarkably correlated with the prognosis of docetaxel in NSCLC, which indicates that EGFR G873R may be employed as a promising biomarker to identify individuals with better prognosis of docetaxel and as an antitumor target for NSCLC treatment.

Antitumor activity of everolimus in recurrent metastatic endometrial cancer with PTEN deletion: a case report

Endometrial cancer (EC) is one of the most common gynecological tumors. The first-line treatment for advanced EC is chemoradiotherapy. However, patients in poor health, such as those with intestinal obstruction, have limited tolerance for the side effects of chemoradiotherapy. Individualized precision treatment may bring new hope to these patients. Herein, we have reported on a 56-year-old female patient with metastatic EC combined with severe intestinal obstruction. Due to her inability to tolerate needle biopsy and standard treatment protocols, next-generation sequencing (NGS)-based circulating tumor DNA (ctDNA) testing was performed and PTEN deletion was found. Following, the patient commenced everolimus (10 mg, qd) treatment and partial shrinkage of metastases was observed one month later. Then, everolimus (10 mg, qd) plus carboplatin (100 mg d1, 8, 15, q28d) for 2 cycles, everolimus (10 mg, qd) plus carboplatin (200 mg d1, 8, q21d) for 2 cycles, and everolimus (10 mg, qd) plus carboplatin (200 mg d1, 2, q21d) for 2 cycles were performed, and the patient got partial response for 10 months. From June 2019, the patient continued to benefit from everolimus and subsequently experienced continued benefit for more than 12 months. This is the first reported case of an EC patient who benefited from everolimus as a first-line treatment based on PTEN deletion. This case provides important clinical experience for the precision treatment of patients with advanced EC.

The effectiveness of afatinib in patients with lung adenocarcinoma harboring complex epidermal growth factor receptor mutation

Background and aims:

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are effective against classical EGFR mutations in lung cancer. However, their effectiveness and the prognosis of lung cancer patients with complex EGFR mutations are not well delineated. Therefore, we aimed to investigate the treatment effectiveness of different EGFR TKIs in patients with complex EGFR mutations.

Patients and methods:

From 2005 to 2020, we collected lung adenocarcinoma tissue samples for EGFR mutation analysis using direct Sanger sequencing. Patients with EGFR mutations treated with EGFR TKIs as first-line treatment were enrolled. Clinical characteristics, EGFR mutation status, treatment response, progression-free survival (PFS), and overall survival (OS) were analyzed.

Results:

Among 2675 patients with EGFR mutations, 239 (8.9%) had complex EGFR mutations, of whom 125 received EGFR TKI treatment as first-line treatment. Multivariate analysis revealed that afatinib was a more favorable factor for PFS than gefitinib [hazard ratio (HR), 2.01; 95% confidence interval (CI), 1.11–3.62] and erlotinib (HR, 2.61; 95% CI, 1.31–5.22), especially in patients with uncommon mutation patterns. Afatinib treatment as first-line treatment was also associated with longer OS compared with erlotinib (HR, 2.48; 95% CI, 1.20–5.12). Classical mutation pattern was associated with longer PFS (p = 0.001) and OS (p = 0.020). Secondary T790M was detected in 22 of 52 (42.3%) patients who had re-biopsied tissue samples after acquiring resistance to EGFR TKIs. There was no significant difference in secondary T790M formation after acquired resistance to the three EGFR TKIs (p = 0.261). Furthermore, three (5.8%) patients had small-cell lung cancer transformation.

Conclusion:

Afatinib is an effective first-line treatment for patients with lung adenocarcinoma harboring complex EGFR mutations, especially those with uncommon mutation patterns.

The emerging treatment landscape of targeted therapy in non-small-cell lung cancer

Lung cancer is one of the most common cancer in the world. In 2018, there were over 2 million new cases of lung cancer and over 1.7 million deaths were attributed to lung cancer. Targeted therapy has emerged as an important mean of the disease management for patients with non-small-cell lung cancer (NSCLC). Herein, we review and analyze recent literature, discuss the targeting pathways and ongoing clinical trials in lung cancer. Chemotherapy is no longer the best available treatment for all patients. Therapeutic decisions should be guided by an understanding of the molecular features of patient's tumor tissues. The future gains will likely emerge from finding optimal ways of combining targeted therapy, immunotherapy, and chemotherapy.

Update on liquid biopsy in clinical management of non-small cell lung cancer

Lung cancer, a leading cause of cancer-related mortality, has a low rate of early diagnosis and a poor prognosis for advanced stages. Recent advances in further mastery of the biology of tumors promote the diagnosis and therapy, especially for non-small cell lung cancer (NSCLC). However, tumor tissue-based information is often not available in most cases due to the invasive and high risk nature of the tumor biopsy procedures. Liquid biopsy, based on the multiple liquid samples including circulating tumor cells (CTC), circulating tumor DNA (ctDNA), and tumor-derived exosome obtained from blood or urine as well as other body fluids, can also provide valuable tumor-related information, playing an important role in management of NSCLC in clinical practice. It is widely believed that concordance of detection for tumor by liquid samples in comparison with tissue biopsy for both early and advanced stage NSCLC patients is optimistic. We herein review the current and future clinical application of liquid biopsy, including early diagnosis and management of precise personalized treatment in lung cancer. The future directions of development for liquid biopsy are also discussed in this review.

Clinical Impact of Rare and Compound Mutations of Epidermal Growth Factor Receptor in Patients With Non-Small-Cell Lung Cancer

BACKGROUND

Standard therapy of advanced non-small-cell lung cancer harboring an activating mutation in the epidermal growth factor receptor (EGFR) gene is treatment with tyrosine kinase inhibitors (TKI). However, for rare and compound mutations of the EGFR gene, the clinical evidence of TKI therapy is still unclear.

PATIENTS AND METHODS

A total of 2906 lung cancer samples were analyzed for EGFR mutations during routine analysis between 2010 and 2017. The samples have been investigated by Sanger sequencing and since 2014 by next-generation sequencing.

RESULTS

We detected EGFR mutations in 408 specimens (14%). Among these, we found 41 samples with rare and 22 with compound mutations. In these 63 samples, 56 different rare EGFR mutations occurred. Information about the clinical outcome was available for 37. Among those with rare mutations, only one patient harboring the mutation p.G874D had disease that responded to first-generation TKI therapy. In contrast, the disease of all patients with compound mutations responded to first- or second-generation TKI therapy. Furthermore, we collected data on clinical relevance regarding TKI therapy from different databases and from an additional literature search, and only found data for 36 of the 56 detected rare mutations.

CONCLUSION

Information about the clinical outcome of patients with rare and compound EGFR mutations remains limited. At present, second- and third-generation TKIs are available, which may represent new treatment strategies for these patients. Therefore, it is becoming increasingly important to maintain databases concerning rare EGFR mutations.

Conventional transbronchial needle aspiration is promising for identifying EGFR mutations in lung adenocarcinoma

Background

Conventional transbronchial needle aspiration (TBNA) is advantageous for the one‐step diagnosis and staging of lung adenocarcinoma under topical anesthesia and conscious sedation. We examined its efficacy for identifying EGFR mutations.

Methods

Forty‐seven patients with proven or suspected lung adenocarcinoma indicated for hilar‐mediastinal lymph node (LN) staging between June 2011 and December 2017 were enrolled. The cellblock was prepared using the plasma‐thrombin method. TaqMan PCR was used to detect mutations. Considering cost effectiveness, only the sample with the highest tumor cell fraction in the same patient was chosen for analysis.

Results

TBNA provided positive results of malignancy in 27 patients. Seventeen patients (63.0%) had cellblocks eligible for mutation testing. Bronchial biopsy (n = 6), neck LN fine needle aspiration (n = 1), and brushing (n = 1), provided higher tumor cell fractions for analysis in eight patients. TBNA was the exclusive method used in nine patients (19.1%). For patients with an inadequate TBNA cellblock, bronchial biopsy (n = 5), neck LN fine needle aspiration (n = 3), computed tomography‐guided transthoracic needle biopsy (n = 1), and brushing (n = 1) were used for analysis. Modification to specimen processing to prevent exhaustion by cytology after June 2016 improved the adequacy of cellblock samples (9/10, 90% vs. 8/17, 47.1%; P = 0.042).

Conclusions

These findings suggest the promising role of conventional TBNA and highlight the challenges of doing more with less in an era of precision medicine.

Differences in the genomic profiles of cell-free DNA between plasma, sputum, urine, and tumor tissue in advanced NSCLC

Liquid biopsy has provided an efficient way for detection of gene alterations in advanced non-small-cell lung cancer (NSCLC). However, the correlation between systematic determination of somatic genomic alterations in liquid biopsy and tumor biopsy still remained unclear, and the concordance rate between cell-free DNA (cfDNA) and matched tumor tissue DNA needs to be increased. A prospective study was performed to detect differences in genetic profiles of cfDNA in sputum, plasma, urine, and tumor tissue from 50 advanced NSCLC patients in parallel by the same next-generation sequencing (NGS) platform. Driver genes alterations were identified in cfDNA sample and matched tumor sample, with an overall concordance rate of 86% in plasma cfDNA, 74% in sputum cfDNA, 70% in urine cfDNA, and 90% in cfDNA of combination of plasma, sputum, and urine. And the concordant rate of cfDNA in sputum in patients with smoking history was higher than that in patients without history of smoking (89% vs. 66%, P = 0.033) and equal to that in plasma cfDNA of the smoking patients (89% vs. 89%). In conclusion, sputum cfDNA can be considered as an alternative medium to liquid biopsy, while the complementarity of genomic profiles in cfDNA among plasma, sputum, and urine was beneficial to detect more diver genes alterations and improve the utility of liquid biopsy in advanced NSCLC (Liquid Biopsy for Detection of Driver Mutation in NSCLC; NCT02778854).

First-generation EGFR tyrosine kinase inhibitor therapy in 106 patients with compound EGFR-mutated lung cancer: a single institution's clinical practice experience

Background

The antitumour efficacy of tyrosine kinase inhibitors (TKIs) in lung cancer patients with compound epidermal growth factor receptor (EGFR) mutations has not been resolved. Our study summarizes a single institutional experience of first-generation TKI therapy for lung cancers with compound EGFR mutations.

Methods

A total of 106 consecutive patients with tumours bearing compound EGFR mutations were identified between January 2012 and May 2016; all patients received first-generation TKI therapy. Deletions in exon 19 and the L858R point mutation in exon 21 were considered common mutations; T790M was considered separately because of its association with TKIs resistances. Any other mutation was defined as a rare mutation. Patients were divided as follows: double common mutations (group A); common plus T790M mutations (group B); common plus rare mutations (group C); double rare mutations (group D); and rare plus T790M mutations (group E). A separate group of 115 consecutive patients with a single common mutation was created for comparative analysis (group F).

Results

The frequency of patients with compound EGFR was 2.9% (114/3925) and their response rate to first-generation TKIs was 50.9%, which was not significantly different from group F (67.0%, P = 0.088). The progression-free survival (PFS) of the 106 patients receiving TKI therapy was worse than that of group F (median, 9.1 vs. 13.0 months, respectively; P < 0.001). The PFS of the compound mutation group was shorter than that of the single common mutation group (median, 10.1 months in group A, P = 0.240; 9.1 months in group B, P < 0.001; 9.6 months in group C, P = 0.010; 6.5 months in group D, P = 0.048; 5.4 months in group E, P = 0.017). Patients with a co-occurring mutation in exon 20 (excluding T790M) exhibited significantly worse PFS than the patients with other compound mutations or with a single common mutation (median, 6.5 vs. 9.1 vs. 13.0 months, respectively, P = 0.002).

Conclusions

There was significant heterogeneity among the compound EGFR mutations and their response to first-generation TKIs. Individualized treatment in clinical practice should be considered for each case.

The value of radial endobronchial ultrasound-guided bronchial brushing in peripheral non-squamous non-small cell lung cancer

Radial endobronchial ultrasound (R-EBUS) is one important diagnostic approach in non-small cell lung cancers (NSCLC). However, the small samples obtained from R-EBUS-guided transbronchial biopsies are sometimes insufficient for pathological and molecular diagnosis. Herein, we investigated the suitability of R-EBUS-guided bronchial brushing specimens for NSCLC diagnosis and EGFR genotyping. We enrolled 941 consecutive patients with peripheral pulmonary lesions who underwent R-EBUS. Cytology-positive brushing specimens from non-squamous NSCLC patients were tested for EGFR mutations. Non-squamous NSCLC was diagnosed in 624 patients (66.3%). Positive cytology was documented in the brushing samples of 376 patients (60.3%). Higher diagnostic yields were obtained in patients exhibiting bronchus signs on chest tomography, and those with R-EBUS probe located within the lesion. EGFR genotyping was successfully performed in 363 samples (96.5% of cytology-positive brushing samples). EGFR genotyping concordance between brushing specimens and matched tissue samples was 88.7% (kappa = 0.745, P < 0.001). Furthermore, 144 non-squamous NSCLC patients (23.1%) with failed pathological diagnosis or EGER sequencing by R-EBUS-guided transbronchial biopsy required repeat biopsies. However, it was achieved successfully from the brushing specimens of 57 patients (39.6%). In conclusion, for patients with peripheral lung cancer, R-EBUS-guided bronchial brushing could provide an additional sampling method for diagnosis and EGFR genotyping.

EGFR-activating mutations, DNA copy number abundance of ErbB family, and prognosis in lung adenocarcinoma

In this study, EGFR-activating mutation status and DNA copy number abundances of members of ErbB family were measured in 261 lung adenocarcinomas. The associations between DNA copy number abundances of ErbB family, EGFR-activating mutation status, and prognosis were explored. Results showed that DNA copy number abundances of EGFR, ERBB2, ERBB3, and ERBB4 had associations with overall survival in lung adenocarcinoma with EGFR-activating mutations. In the stratification analysis, only ERBB2 showed significant discrepancy in patients carrying wild type EGFR and other members of ErbB family in patients carrying EGFR-activating mutation. This indicated that CNAs of ErbB family had effect modifications of EGFR-activating mutation status. Findings of this study demonstrate potential molecular guidance of patient management of lung adenocarcinoma with or without EGFR-activating mutations.

Epidermal growth factor receptor mutation enhances expression of vascular endothelial growth factor in lung cancer

Epidermal growth factor receptor (EGFR) activation has been demonstrated to have a critical role in tumor angiogenesis. In the present study, the correlation between EGFR mutations and vascular endothelial growth factor (VEGF) was investigated in lung cancer cell lines and non-small-cell lung cancer (NSCLC) tumor tissues. VEGF levels were significantly increased in culture medium of lung cancer cells and NSCLC tissues with EGFR mutations (H1650 vs. A549, P=0.0399; H1975 vs. A549, P<0.0001). Stable lung cancer cell lines expressing mutant (exon 19 deletion, E746-A750; exon 21 missense mutation, L858R) and wild-type EGFR genes were established. Significantly increased expression of VEGF and stronger inhibitory effects of gefitinib to VEGF expression were observed in exon 19 deletion stable lung cancer cells (exon 19 deletion vs. wild-type EGFR, P=0.0005). The results of the present study may provide an insight into the association of mutant EGFR and VEGF expression in lung cancer, and may assist with further development of targeted therapy for NSCLC in the future.

Effectiveness of tyrosine kinase inhibitors on uncommon E709X epidermal growth factor receptor mutations in non-small-cell lung cancer

BACKGROUND

Clinical features of epidermal growth factor receptor (EGFR) mutations: L858R, deletions in exon 19, T790M, insertions in exon 20, G719X, and L861X in non-small-cell lung cancer (NSCLC) are well-known. The clinical significance of other uncommon EGFR mutations, such as E709X, is not well understood. This study aimed to improve the understanding of E709X, and the clinical response to tyrosine kinase inhibitors (TKIs) of NSCLC patients with such an uncommon mutation.

METHODS

Specimens from 3,146 patients were tested for EGFR mutations. We surveyed the clinical data and the effectiveness of TKI treatment in NSCLC patients with EGFR mutations E709X.

RESULTS

Of the 3,146 patients, 1,689 (53.7%) had EGFR mutations. This included 726 patients with deletions in exon 19, 733 patients with L858R, and 230 (13.6%) patients with other EGFR mutations. In the 230 patients who had mutations other than single deletion in exon 19 or single L858R in exon 21, 25 (1.5%) patients had the uncommon E709X mutations. Twenty patients had complex E709X mutations and five had single E709X mutation: delE709-T710insD. Of these 25 patients, 18 received either gefitinib or erlotinib treatment. The response rate of TKIs treatment was 50.0%, and the median progression-free survival was 6.2 months. All 5 patients who had delE709-T710insD were non-responders to TKI treatments.

CONCLUSION

E709X EGFR mutations constituted a small part of the whole group of EGFR mutations. Most patients had complex mutations. The mutation delE709-T710insD was a single mutation and was not associated with good response to TKI treatment.

Implementation and Quality Control of Lung Cancer EGFR Genetic Testing by MALDI-TOF Mass Spectrometry in Taiwan Clinical Practice

Molecular diagnostics in cancer pharmacogenomics is indispensable for making targeted therapy decisions especially in lung cancer. For routine clinical practice, the flexible testing platform and implemented quality system are important for failure rate and turnaround time (TAT) reduction. We established and validated the multiplex EGFR testing by MALDI-TOF MS according to ISO15189 regulation and CLIA recommendation in Taiwan. Totally 8,147 cases from Aug-2011 to Jul-2015 were assayed and statistical characteristics were reported. The intra-run precision of EGFR mutation frequency was CV 2.15% (L858R) and 2.77% (T790M); the inter-run precision was CV 3.50% (L858R) and 2.84% (T790M). Accuracy tests by consensus reference biomaterials showed 100% consistence with datasheet (public database). Both analytical sensitivity and specificity were 100% while taking Sanger sequencing as the gold-standard method for comparison. EGFR mutation frequency of peripheral blood mononuclear cell for reference range determination was 0.002 ± 0.016% (95% CI: 0.000–0.036) (L858R) and 0.292 ± 0.289% (95% CI: 0.000–0.871) (T790M). The average TAT was 4.5 working days and the failure rate was less than 0.1%. In conclusion, this study provides a comprehensive report of lung cancer EGFR mutation detection from platform establishment, method validation to clinical routine practice. It may be a reference model for molecular diagnostics in cancer pharmacogenomics.

Clinical and the prognostic characteristics of lung adenocarcinoma patients with ROS1 fusion in comparison with other driver mutations in East Asian populations

INTRODUCTION

The prevalence, demographic features, and clinical outcomes of lung adenocarcinoma patients with novel ROS1 oncogenic rearrangement in East Asian populations are not clear. This study aimed to investigate the clinical and prognostic characteristics of lung adenocarcinoma in patients with ROS1 fusion compared with other driver mutations.

METHODS

Multiplex reverse transcription-polymerase chain reaction was used to detect the ROS1 fusion gene in lung adenocarcinoma cases. Immunohistochemistry was used to confirm the expression of ROS1. The demographic data and clinical outcomes of patients with the ROS1 fusion gene were compared with those of patients without the ROS1 fusion gene, including those with the EGFR mutation, EML4-ALK fusion, KRAS mutation, and quadruple-negative patients.

RESULTS

Of 492 patients with lung adenocarcinoma, 12 (2.4%) had the ROS1 fusion gene. Their median age was 45.0 years, significantly younger than that of the ROS1 fusion-negative cohorts (p < 0.001). Acinar (including cribriform) and solid patterns were the two most common histologic subtypes in the ROS1 fusion tumors (7 of 12, 58.3%) and were predominantly seen in CD74-ROS1 fusion tumors (66.7%). There was no significant survival difference between the ROS1 fusion-positive and ROS1 fusion-negative cohorts in surgical group, but ROS1 fusion-positive patients might have worse outcomes than EGFR-mutant patients in the stage IV group.

CONCLUSIONS

The ROS1 fusion gene can be successfully detected in East Asian patients with lung adenocarcinoma using multiplex reverse transcription-polymerase chain reaction. These patients tend to be younger and have characteristic histologic subtypes. Due to the small number of ROS1 fusion patients, the prognostic value of ROS1 fusion need further studies to confirm.

V843I, a lung cancer predisposing EGFR mutation, is responsible for resistance to EGFR tyrosine kinase inhibitors

INTRODUCTION

We previously demonstrated that a family predisposed to lung cancer harbored a V843I substitution in the epidermal growth factor receptor (EGFR) protein. We report here the further characterization of this mutant EGFR protein in the context of tumorigenicity and resistance to tyrosine kinase inhibitors (TKIs) of EGFR activity.

METHODS

Phosphorylation of EGFR and downstream signaling proteins of lung adenocarcinoma cell lines with EGFR mutations was assayed by flow cytometry. Susceptibility to TKIs of these cell lines, with or without suppression of mutant EGFR expression by small inhibitory RNA (siRNA), was investigated using a cellular viability assay. Furthermore, protein modeling was used to predict TKI binding to EGFR protein carrying the V843I mutation.

RESULTS

Phosphorylation of EGFR and downstream signaling proteins was elevated upon transfection with an EGFR gene with the V843I. Although the cell line with V843I + L858R demonstrated resistance to EGFR-TKIs, the cells became susceptible to TKIs upon incubation with siRNA specific for the V843I allele. The structural analysis suggested that TKI binding to EGFR would be sterically hindered by Arg841 in the double-mutant (V843I + L858R) EGFR.

CONCLUSIONS

The V843I mutation contributes to tumorigenesis by promoting phosphorylation of EGFR and its downstream signaling proteins. This mutation also appears to provide resistance to EGFR-TKIs through structural modification of EGFR. These features are comparable with those in EGFR T790M mutation, suggesting that cases with germ-line V843I or T790M mutations could be categorized as a class of familial lung cancer syndrome with resistance to EGFR-TKIs.

Blood as a Substitute for Tumor Tissue in Detecting EGFR Mutations for Guiding EGFR TKIs Treatment of Nonsmall Cell Lung Cancer: A Systematic Review and Meta-Analysis

Tumor tissues are often absent or insufficient for testing epidermal growth factor receptor (EGFR) mutations to guide EGFR tyrosine kinase inhibitors (TKIs) treatment of patients with nonsmall cell lung cancer (NSCLC). We conducted this systematic review and meta-analysis to assess whether blood can be used as a substitute for tumor tissue in detecting EGFR mutations. MEDLINE, EMBASE, and the Cochrane Library were searched for studies that provided data to estimate the accuracy of blood testing against tissue testing in NSCLC patients and/or those directly compared the efficacy of EGFR TKIs in EGFR mutant and wild-type patients according to sources of specimens. Sensitivity, specificity, and concordance rate were used as measures of the accuracy. Risk ratio (RR) for objective response and hazard ratio (HR) for progression-free survival (PFS) and overall survival (OS) were used as measures for treatment efficacy. We combined the effects by using the fixed-effects model unless there was evidence of heterogeneity, in which case a random-effects mode was used. This systematic review included 25 studies with 2605 patients. The pooled overall sensitivity, specificity, and concordance rate were 0.61, 0.90, and 0.79, respectively. Serum showed lower sensitivity (0.56 vs 0.65) but higher specificity (0.95 vs 0.85) and higher concordance (0.86 vs 0.74) than plasma. EGFR mutations (exon 19 or 21) in blood were significantly associated with objective response (RR: 4.08; 95% confidence interval [CI] 2.48-6.70), PFS (HR: 0.72; 95% CI 0.64-0.80), and OS (HR: 0.71; 95% CI 0.50-0.99). Importantly, the association of the mutations with the 3 clinical outcomes for serum was similar to that for tumor tissue and higher than that for plasma. Blood, in particular serum, is a good substitute when tumor tissue is absent or insufficient for testing EGFR mutations to guide EGFR TKIs treatment in patients with NSCLC. EGFR mutation positivity in blood could be used to recommend EGFR TKIs treatment, but the absence of blood positivity should not necessarily be construed with confirmed negativity.

Comparison of uncommon EGFR exon 21 L858R compound mutations with single mutation

Non-small-cell lung cancer with epidermal growth factor receptor (EGFR) mutation is sensitive to EGFR tyrosine kinase inhibitors (TKIs). But little is known about the response to EGFR TKIs and the prognostic role of compound mutations. This study compared the uncommon EGFR exon 21 L858R compound mutations with single mutation to characterize EGFR compound mutations and investigated their response to EGFR TKI treatment. We retrospectively screened 799 non-small-cell lung cancer patients from August 1, 2009 to June 1, 2012 by EGFR mutation testing. EGFR mutations were detected in 443 patients, with 22 (4.97%) compound mutations. Subsequently, six patients with EGFR exon 21 L858R compound mutations and 18 paired patients with single L858R mutation were well characterized. Finally, we also analyzed the EGFR TKI treatment response and patients’ outcomes of compound or single L858R mutations. There was no differential treatment effect on the disease control rate and objective response rate between the L858R compound mutations and single mutation groups. No significant difference in overall survival or progression-free survival of these two groups was found by log-rank test. In conclusion, we demonstrated that no significant difference was detected in the response to EGFR TKIs and patients’ outcomes in the compound and single mutation groups.

Comparison of epidermal growth factor receptor mutations between primary tumors and lymph nodes in non-small cell lung cancer: a review and meta-analysis of published data

BACKGROUND

Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) can predict the clinical response to tyrosine kinase inhibitor (TKI) therapy. However, EGFR mutations may be different in primary tumors (PT) and metastatic lymph nodes (MLN). The aim of this study was to compare EGFR mutations between PT and the corresponding MLN in NSCLC patients, and provide some guidelines for clinical treatment using TKI therapy.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed with several research databases. Relative risk (RR) with the 95% confidence interval (CI) were used to investigate the EGFR mutation status between PT and the corresponding MLN. A random-effects model was used.

RESULTS

9 publications involving 707 patients were included in the analysis. It was found that activation of EGFR mutations identified in PT and the corresponding MLN was 26.4% (187/707) and 19.9% (141/707), respectively. The overall discordance rate in our meta-analysis was 12.2% (86/707). The relative risk (RR) for EGFR mutation in PT relative to MLN was 1.33 (95%CI: 1.10-1.60; random-effects model). There was no significant heterogeneity between the studies (I2=5%, p=0.003).

CONCLUSIONS

There exists a considerable degree of EGFR mutation discrepancy in NSCLC between PT and corresponding MLN, suggesting that tumor heterogeneity might arise at the molecular level during the process of metastasis.

HER family kinase domain mutations promote tumor progression and can predict response to treatment in human breast cancer

Resistance to HER2-targeted therapies remains a major obstacle in the treatment of HER2-overexpressing breast cancer. Understanding the molecular pathways that contribute to the development of drug resistance is needed to improve the clinical utility of novel agents, and to predict the success of targeted personalized therapy based on tumor-specific mutations. Little is known about the clinical significance of HER family mutations in breast cancer. Because mutations within HER1/EGFR are predictive of response to tyrosine kinase inhibitors (TKI) in lung cancer, we investigated whether mutations in HER family kinase domains are predictive of response to targeted therapy in HER2-overexpressing breast cancer. We sequenced the HER family kinase domains from 76 HER2-overexpressing invasive carcinomas and identified 12 missense variants. Patients whose tumors carried any of these mutations did not respond to HER2 directed therapy in the metastatic setting. We developed mutant cell lines and used structural analyses to determine whether changes in protein conformation could explain the lack of response to therapy. We also functionally studied all HER2 mutants and showed that they conferred an aggressive phenotype and altered effects of the TKI lapatinib. Our data demonstrate that mutations in the finely tuned HER kinase domains play a critical function in breast cancer progression and may serve as prognostic and predictive markers.

Biospecimen repositories and cytopathology

Biospecimen repositories are important for the advancement of biomedical research. Literature on the potential for biobanking of fine-needle aspiration, gynecologic, and nongynecologic cytology specimens is very limited. The potential for biobanking of these specimens as valuable additional resources to surgically excised tissues appears to be excellent. The cervicovaginal specimens that can be used for biobanking include Papanicolaou-stained monolayer preparations and residual material from liquid-based cytology preparations. Different types of specimen preparations of fine-needle aspiration and nongynecologic specimens, including Papanicolaou-stained and Diff-Quik-stained smears, cell blocks. and dedicated passes/residual material from fine-needle aspiration stored frozen in a variety of solutions, can be used for biobanking. Because of several gaps in knowledge regarding the standard of operative procedures for the procurement, storage, and quality assessment of cytology specimens, further studies as well as national conferences and workshops are needed not only to create awareness but also to facilitate the use of cytopathology specimens for biobanking.

Molecular diagnostic testing of cytology specimens: current applications and future considerations

Molecular mechanisms of pathogenesis continue to be discovered, accelerating significant expansion of the spectrum of clinically useful molecular diagnostic tests and their incorporation into patient care algorithms. Currently, molecular assays facilitate identification of infectious processes, detection of specific constitutional and somatically acquired pathogenic mutations, guidance of therapy selection, and monitoring of treatment response and disease progression. The correlation of genomic test results with clinical, morphologic, and immunophenotypic findings has defined the practice of "precision medicine" with wide-reaching implications for health care. As novel promising techniques such as microarrays and next-generation sequencing are adopted by health care providers, new practice standards are being developed for incorporation into practice. Cytology specimens are good sources of high-quality nucleic acids. Although sometimes limited in quantity, in many cases such specimens are well suited for molecular diagnostic testing, which is capable of maximizing the number of tests from small amounts of sample. The pathologist continues to serve as a central resource for diagnostic testing and consultation regarding appropriate use of molecular tests. Understanding current methodologies, clinical utility of currently available nucleic acid tests, validation requirements for test implementation, quality assurance metrics, and future technology trends is essential to the practice of contemporary molecular pathology.

New targeted molecular therapies for cancer: radiological response in intrathoracic malignancies and cardiopulmonary toxicity: what the radiologist needs to know

The emergence of new novel therapeutic agents which directly target molecules that are uniquely or abnormally expressed in cancer cells (molecular targeted therapy, MTT) has changed dramatically the treatment of cancer in recent years. The clinical benefit associated with these agents is typically limited to a subset of treated patients, who in many cases are defined by a specific genomic mutations and expression lesion within their tumor cells. All these new therapy modalities represent new challenges to radiologists as their mechanism of action and side effect profiles differ from conventional chemotherapy agents. In this article we will discuss radiological patterns of response to molecular targeted therapies MTT in lung cancer, typical and atypical radiological responses of targeted molecular therapy for other intra thoracic malignancies, cardiopulmonary toxicity and other side effects of molecular targeted therapy MTT in the thorax.

CT-guided needle lung biopsy is possible during apneic oxygenation: a case series

Background

It can be difficult to perform CT guided biopsy of small pulmonary nodules especially if the position is behind a costa or close to the diaphragm and respiratory movements may hamper the procedure. During apneic oxygenation with a pulmonary standstill these movements can be hindered.

Methods

Six patients with decreased lung function and suspicious lung nodules are presented. Under general anesthesia including a muscle relaxant and a cuffed tube in the trachea CT guided biopsy was prepared. Just before the biopsy the ventilation mode was switched to a continuous positive airway pressure of 5–10 cm H₂O, maintaining 100% oxygen delivery without ventilation. If the position of the lung nodule was inconvenient for biopsy the pressure was increased to up to 17 cm H₂O to expand the lungs to a better biopsy position. After retrieving the biopsy controlled ventilation was re-established and a finishing control CT-scan was performed. Blood gas analyses were performed with few minutes interval.

Results

All biopsies were diagnostic. All patients survived the procedure with no major complications, but 3 patients developed pneumothorax. The length of apneic oxygenation was median 10 minutes (8–10 minutes). No major changes in vital parameters were observed, and in all patients the peripheral oxygen saturation was 100% throughout the procedure. The arterial oxygen tension rose to very high values and the lowest pH was 7.18.

Conclusions

It is possible to perform lung biopsies in selected patients with decreased lung function during apneic oxygenation in at least 10 minutes in a safe way.

Feasibility of image-guided transthoracic core-needle biopsy in the BATTLE lung trial

BACKGROUND

As therapy for non-small-cell lung cancer (NSCLC) patients becomes more personalized, additional tissue in the form of core-needle biopsies (CNBs) for biomarker analysis is increasingly required for determining appropriate treatment and for enrollment into clinical trials. We report our experience with small-caliber percutaneous transthoracic (PT) CNBs for the evaluation of multiple molecular biomarkers in BATTLE (biomarker-integrated approaches of targeted therapy for lung cancer elimination), a personalized, targeted therapy NSCLC clinical trial.

METHODS

The medical records of patients who underwent PTCNB for consideration of enrollment in BATTLE were reviewed for diagnostic yield of 11 predetermined molecular markers and procedural complications. Univariate and multivariate analyses of factors related to patient and lesion characteristics were performed to determine possible influences on diagnostic yield.

RESULTS

One hundred and seventy PTCNBs were performed using 20-gauge biopsy needles in 151 NSCLC patients screened for the trial. The biopsy specimens of 82.9% of the patients were found to have adequate tumor tissue for analysis of the required biomarkers. On multivariate analysis, metastatic lesions were 5.4 times more likely to yield diagnostic tissue as compared with primary tumors (p = 0.0079). Pneumothorax and chest tube insertion rates were 15.3% and 9.4%, respectively.

CONCLUSIONS

Image-guided 20-gauge PTCNB is safe and provides adequate tissue for analysis of multiple biomarkers in the majority of patients being considered for enrollment into a personalized, targeted therapy NSCLC clinical trial. Metastatic lesions are more likely to yield diagnostic tissue as compared with primary tumors.

EGFR and KRAS mutation analyses from specimens obtained by bronchoscopy and EBUS-TBNA

BACKGROUD

Procurement of tumor tissue is mandatory for a mutation analysis in patients with non-small cell lung cancer. The purpose of this study was to evaluate the usefulness of bronchoscopic biopsy and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy for detecting epidermal growth factor receptor (EGFR) and KRAS mutations in routine practice.

METHODS

Tumor DNA was extracted from formalin-fixed paraffin-embedded tissues, and amplifications of exons 18-21 of EGFR and codons 12, 13 and 61 of KRAS were performed using polymerase chain reaction (PCR). PCR products were subjected to direct sequencing in both directions.

RESULTS

Of 211 consecutive specimens, 201 (95.3%) were available for EGFR mutation analysis, and 196 (92.9%) were adequate for KRAS mutation analysis. EGFR and KRAS mutations were detected in 14.9% and 5.4%, respectively. A median of 16 days was spent from biopsy to the final report for either EGFR or KRAS mutation status. The detection rates for both mutations were similar between bronchoscopic biopsy and EBUS-TBNA (P > 0.05). Female gender (53.3%), never smoker (63.3%), and adenocarcinoma (96.7%) were predominant in patients with EGFR mutations. Among patients with adenocarcinoma (n = 104), the frequencies of EGFR and KRAS mutations were 27.9% and 10.6%, respectively.

CONCLUSIONS

Small tissue samples obtained by bronchoscopic biopsy and EBUS-TBNA are sufficient for detecting EGFR and KRAS mutations in routine practice. Therefore, concurrent mutational analyses of small tissue samples should be considered at the time of initial diagnosis.

Phosphorylated insulin-like growth factor-1 receptor (pIGF1R) is a poor prognostic factor in brain metastases from lung adenocarcinomas

A greater understanding of brain metastases is imperative for developing novel therapeutic strategies. Our previous study showed that insulin-like growth factor (IGF) signaling pathway was activated in brain-tropic cancer cells. In this study, we investigated the clinical relevance of activated (phosphorylated) IGF-1 receptor (pIGF1R) expression in brain metastases originating from lung adenocarcinomas. All pathologically confirmed brain metastases from lung adenocarcinomas, with available archived specimens from January 1998 to December 2009 at National Taiwan University Hospital, were assessed immunohistochemically for pIGF1R expression using H-score criteria. A median H-score was used as a cutoff point to define high or low pIGF1R expression. The mutation status in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) was examined using direct sequencing. The prognostic significance of pIGF1R expression, its correlations with clinicopathological characteristics, and EGFR status were evaluated. In the 86 cases, high membranous/cytoplasmic pIGF1R expression in brain metastases correlated with a shorter median survival (10.8 vs 27.8 mo, P = 0.003). This correlation was more significant in patients with EGFR mutations [hazard ratio (HR) 2.38, 95 % confidence interval (CI) 1.19-4.77 for EGFR mutations; HR 1.99, 95 % CI 0.95-4.15 for EGFR wild type] and remained statistically significant in multivariate analysis after adjusting for the effects of other potential prognostic factors, including the graded prognostic assessment score, solitary brain metastasis, extracranial metastatic status, EGFR mutations, and treatment using EGFR tyrosine kinase inhibitors. Although we also identified nuclear pIGF1R expression, this result was prognostically non-significant. Our study results showed that high membranous/cytoplasmic pIGF1R expression in brain metastases was a poor prognostic factor, more significantly in patients with EGFR mutations than in those with wild-type EGFRs.

Uncommon epidermal growth factor receptor mutations in non-small cell lung cancer and their mechanisms of EGFR tyrosine kinase inhibitors sensitivity and resistance

Therapy targeted against the epidermal growth factor receptor (EGFR) has demonstrated dramatic tumor responses and favorable clinical outcomes in a select group of non-small cell lung cancer (NSCLC) patients whose tumors harbor EGFR activating mutations. The best characterized of the mutations conferring sensitivity to EGFR tyrosine kinase inhibitors (TKIs) are deletions in exon 19 and a point mutation in exon 21 (L858R). Likewise, the most common mutation that confers resistance is the T790M point mutation. However several other mutations have been reported and several have been characterized as regards their role in sensitivity or resistance to EGFR TKIs. Resistance to the EGFR TKIs erlotinib and gefitinib, and the newer irreversible EGFR TKIs is a problem of fundamental importance. Recognition of the presence and significance of specific EGFR mutations is important for appropriate therapeutic implementation of EGFR TKIs and research and development of mutation-specific inhibitors. We summarize the literature and present an overview of the subject of less common EGFR mutations and their clinical significance, with an emphasis on EGFR TKI sensitivity or resistance.

Impact of family history of cancer on the incidence of mutation in epidermal growth factor receptor gene in non-small cell lung cancer patients

BACKGROUND

Epidermal growth factor receptor (EGFR) activating mutation is an important predictive biomarker of EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC), while family history of cancer also plays an important role in the neoplasia of lung cancer. This study aimed to investigate the association between family history of cancer and EGFR mutation status in NSCLC population.

METHODS

From February 2008 to May 2012, 538 consecutive NSCLC patients with known EGFR mutation status were included into this study. Amplification refractory mutation system (ARMS) method was used to detect EGFR mutation. The associations between EGFR mutation and family history of cancer were evaluated using logistic regression models.

RESULTS

EGFR activating mutation was found in 220 patients and 117 patients had family cancer histories among first-degree relatives. EGFR mutation was more frequently detected in adenocarcinoma patients (p < 0.001), never-smoker (p < 0.001) and with family history of cancer (p = 0.031), especially who had family history of lung cancer (p = 0.008). In multivariate analysis, the association of EGFR mutation with family history of cancer also existed (p = 0.027).

CONCLUSIONS

NSCLC patients with family history of cancer, especially family history of lung cancer, might have a significantly higher incidence of EGFR activating mutation.

EGFR-targeted therapy for non-small cell lung cancer: focus on EGFR oncogenic mutation

The two essential requirements for pathologic specimens in the era of personalized therapies for non-small cell lung carcinoma (NSCLC) are accurate subtyping as adenocarcinoma (ADC) versus squamous cell carcinoma (SqCC) and suitability for EGFR molecular testing, as well as for testing of other oncogenes such as EML4-ALK and KRAS. Actually, the value of EGFR expressed in patients with NSCLC in predicting a benefit in terms of survival from treatment with an epidermal growth factor receptor targeted therapy is still in debate, while there is a convincing evidence on the predictive role of the EGFR mutational status with regard to the response to tyrosine kinase inhibitors (TKIs).This is a literature overview on the state-of-the-art of EGFR oncogenic mutation in NSCLC. It is designed to highlight the preclinical rationale driving the molecular footprint assessment, the progressive development of a specific pharmacological treatment and the best method to identify those NSCLC who would most likely benefit from treatment with EGFR-targeted therapy. This is supported by the belief that a rationale for the prioritization of specific regimens based on patient-tailored therapy could be closer than commonly expected.

Mechanisms of intrinsic and acquired resistance to kinase-targeted therapies

Cancer drugs that target pivotal signaling molecules required for malignant cell survival and growth have demonstrated striking antitumor activities in appropriately selected patient populations. Unfortunately, however, therapeutic responses are often of limited duration, typically 6-12 months, because of emergence of drug-resistant subclones of tumor cells. In this review, we highlight several of the mechanisms of emergent resistance to several kinase-targeted small molecule therapies used in melanoma, non-small cell lung cancer (NSCLC) and other solid tumors as illustrative examples. We discuss the implications of these findings for the development of new treatment strategies to delay or prevent the onset of drug resistance.

Biomarkers and transcriptome profiling of lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. High-throughput technologies such as microarrays provide an opportunity to explore biomarkers for cancer prevention, prognosis and treatment guidance. Recent studies have revealed many biomarkers with the potential for clinical application. However, major limitations still exist. Although useful data on cancer genomics has accumulated rapidly, there has also been a simultaneous tendency for amplification of the complex relationships among the enormous number of variables that need to be considered. Disentangling these complex gene-gene interactions requires new approaches to data analysis to reveal information that has been obscured by traditional methods. Here, we review the current findings on biomarker identification in lung cancer, address their limitations and discuss some future directions for improvements in this area of research.

Presence of EGFR mutation in pathologically non-malignant specimens from computed tomography-guided lung needle biopsies

Activating mutations of the epidermal growth factor receptor (EGFR) gene are characteristic of non-small cell lung cancer (NSCLC). EGFR mutations were previously detected in histologically normal lung tissue around NSCLC tumors. Computed tomography-guided lung needle biopsy (CTNB) is an accurate and useful technique for the diagnosis of lung tumors. However, pathologically non-malignant cases occasionally become apparent following lung tumor resection. In this study, we determined the EGFR mutational status of lung tumors diagnosed as non-malignant in CTNB specimens, but diagnosed as NSCLC following surgical resection. Between 2000 and 2008, 1,109 CTNBs were performed at Okayama University Hospital. Among them, 15 cases were initially diagnosed as non-malignant by CTNB, but diagnosed as NSCLC following surgical resection as a result of a high likelihood of malignancy by clinical findings. Twelve paired DNAs of CTNB and corresponding resected specimens were available to examine the EGFR mutational status using a mutant-enriched PCR assay. EGFR mutations were detected in one out of 12 CTNB specimens and three of the corresponding resected tumors. This case harbored the same EGFR mutation in the CTNB specimen and resected tumor, but not in the distant corresponding non-malignant lung tissue. Our results indicated that the detection of EGFR mutations may therefore aid the diagnosis of NSCLC in pathologically non-malignant CTNB specimens.

Clinical outcomes in non-small cell lung cancers harboring different exon 19 deletions in EGFR

PURPOSE

Several deletions in exon 19 of epidermal growth factor receptor (EGFR) gene have been reported in non-small cell lung cancer (NSCLC). It is unknown if deletions occurring at different amino acid positions or of different sizes are associated with different clinical outcome to EGFR tyrosine kinase inhibitors (TKI).

EXPERIMENTAL DESIGN

This study enrolled NSCLC patients with deletions in EGFR exon 19. Patients who had received EGFR TKIs for advanced NSCLC were further evaluated for response rate (RR), progression-free survival (PFS), and overall survival (OS).

RESULTS

In 308 patients with deletions in EGFR exon 19, 298 had deletions encompassing the entire amino acid string from L747 through E749 (LRE deletions). EGFR TKIs were used in 204 patients with advanced NSCLC. Patients with non-LRE deletions had the least RR, compared with those with deletions from E746 or L747 (42.9%, 68.2%, and 79.6%, respectively; P = 0.022). Patients with non-LRE deletions had relatively short median PFS, though not significantly different from those with deletions from E746 or L747 (5.9, 9.8, and 10.5 months, respectively; P = 0.665). The OS was not different among patients with deletions occurring at different amino acid positions (P = 0.776). Deletions in exon 19 of different sizes were not associated with different RR, PFS, or OS.

CONCLUSIONS

Non-LRE deletions in exon 19 were associated with worse response to EGFR TKIs, compared with LRE deletions. Therefore, the expected clinical outcome under EGFR TKIs depends on not only the existence but also the types of deletions in exon 19.

Pretreatment epidermal growth factor receptor (EGFR) T790M mutation predicts shorter EGFR tyrosine kinase inhibitor response duration in patients with non-small-cell lung cancer

PURPOSE

Patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR)-activating mutations have excellent response to EGFR tyrosine kinase inhibitors (TKIs), but T790M mutation accounts for most TKI drug resistance. This study used highly sensitive methods to detect T790M before and after TKI therapy and investigated the association of T790M and its mutation frequencies with clinical outcome.

PATIENTS AND METHODS

Direct sequencing, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and next-generation sequencing (NGS) were used to assess T790M in the following two cohorts of patients with NSCLC: TKI-naive patients (n = 107) and TKI-treated patients (n = 85). Results were correlated with TKI treatment response and survival.

RESULTS

MALDI-TOF MS was highly sensitive in detecting and quantifying the frequency of EGFR-activating mutations and T790M (detection limits, 0.4% to 2.2%). MALDI-TOF MS identified more T790M than direct sequencing in TKI-naive patients with NSCLC (27 of 107 patients, 25.2% v three of 107 patients, 2.8%, respectively; P < .001) and in TKI-treated patients (before TKI: 23 of 73 patients, 31.5% v two of 73 patients, 2.7%, respectively; P < .001; and after TKI: 10 of 12 patients, 83.3% v four of 12 patients, 33.3%, respectively; P = .0143). The EGFR mutations and their frequencies were confirmed by NGS. T790M was an independent predictor of decreased progression-free survival (PFS) in patients with NSCLC who received TKI treatment (P < .05, multivariate Cox regression).

CONCLUSION

T790M may not be a rare event before or after TKI therapy in patients with NSCLC with EGFR-activating mutations. The pretreatment T790M mutation was associated with shorter PFS with EGFR TKI therapy in patients with NSCLC.

Use of CT-guided fine needle aspiration biopsy in epidermal growth factor receptor mutation analysis in patients with advanced lung cancer

BACKGROUND

The safety of using a cutting needle when performing a core-needle biopsy is of major concern, in particular for small lung tumors or tumors near the hilum.

PURPOSE

To investigate the usefulness of CT-guided fine needle aspiration biopsy (FNAB) of the lung in obtaining tumor tissue for epidermal growth factor receptor (EGFR) mutation analysis in advanced lung cancer patients.

MATERIAL AND METHODS

Forty-three patients with stage IIIB-IV lung cancer were enrolled. In all patients, CT-guided FNAB was performed using an 18-gauge or 20-gauge Chiba aspiration needle for histology diagnosis and EGFR mutation analysis. Complications associated with CT-guided FNAB were observed, and the specimen mutational assessments were recorded.

RESULTS

The obtained tumor samples ranged from 0.5-1.5 cm in length and were adequate for histological and DNA analyses in all patients. No patient had a pneumothorax or hemoptysis. Minor needle tract bleeding appeared in eight patients. Mutation analysis was satisfactorily demonstrated in 23 mutations and 20 non-mutations. Ten and 13 mutations were identified by 18-gauge and 20-gauge needle biopsies, respectively. EFGR mutations, including 12 cases of EGFR exon 19 deletion and 11 cases of exon 21 point mutation, were present in 21 patients with adenocarcinomas, one with squamous cell carcinoma, and one with undifferentiated carcinoma.

CONCLUSION

CT-guided FNAB is a feasible and safe technique for obtaining lung tumor tissues for EGFR gene mutation analysis.

Including total EGFR staining in scoring improves EGFR mutations detection by mutation-specific antibodies and EGFR TKIs response prediction

Epidermal growth factor receptor (EGFR) is a novel target for therapy in subsets of non-small cell lung cancer, especially adenocarcinoma. Tumors with EGFR mutations showed good response to EGFR tyrosine kinase inhibitors (TKIs). We aimed to identify the discriminating capacity of immunohistochemical (IHC) scoring to detect L858R and E746-A750 deletion mutation in lung adenocarcinoma patients and predict EGFR TKIs response. Patients with surgically resected lung adenocarcinoma were enrolled. EGFR mutation status was genotyped by PCR and direct sequencing. Mutation-specific antibodies for L858R and E746-A750 deletion were used for IHC staining. Receiver operating characteristic (ROC) curves were used to determine the capacity of IHC, including intensity and/or quickscore (Q score), in differentiating L858R and E746-A750 deletion. We enrolled 143 patients during September 2000 to May 2009. Logistic-regression-model-based scoring containing both L858R Q score and total EGFR expression Q score was able to obtain a maximal area under the curve (AUC: 0.891) to differentiate the patients with L858R. Predictive model based on IHC Q score of E746-A750 deletion and IHC intensity of total EGFR expression reached an AUC of 0.969. The predictive model of L858R had a significantly higher AUC than L858R intensity only (p = 0.036). Of the six patients harboring complex EGFR mutations with classical mutation patterns, five had positive IHC staining. For EGFR TKI treated cancer recurrence patients, those with positive mutation-specific antibody IHC staining had better EGFR TKI response (p = 0.008) and longer progression-free survival (p = 0.012) than those without. In conclusion, total EGFR expression should be included in the IHC interpretation of L858R. After adjusting for total EGFR expression, the scoring method decreased the false positive rate and increased diagnostic power. According to the scoring method, the IHC method is useful to predict the clinical outcome and refine personalized therapy.