Activating mutations within the EGFR kinase domain: a molecular predictor of disease-free survival in resected pulmonary adenocarcinoma

Predicting Postoperative Lung Cancer Recurrence and Survival Using Cox Proportional Hazards Regression and Machine Learning

BACKGROUND

Surgical resection remains the standard treatment for early-stage lung cancer. However, the recurrence rate after surgery is unacceptably high, ranging from 30% to 50%. Despite extensive efforts, accurately predicting the likelihood and timing of recurrence remains a significant challenge. This study aims to predict postoperative recurrence by identifying novel image biomarkers from preoperative chest CT scans.

METHODS

A cohort of 309 patients was selected from 512 non-small-cell lung cancer patients who underwent lung resection. Cox proportional hazards regression analysis was employed to identify risk factors associated with recurrence and was compared with machine learning (ML) methods for predictive performance. The goal is to improve the ability to predict the risk and time of recurrence in seemingly "cured" patients, enabling personalized surveillance strategies to minimize lung cancer recurrence.

RESULTS

The Cox hazards analyses identified surgical procedure, TNM staging, lymph node involvement, body composition, and tumor characteristics as significant determinants of recurrence risk, both for local/regional and distant recurrence, as well as recurrence-free survival (RFS) and overall survival (OS) (p < 0.05). ML models and Cox models exhibited comparable predictive performance, with an area under the receiver operative characteristic (ROC) curve (AUC) ranging from 0.75 to 0.77.

CONCLUSIONS

These promising findings demonstrate the feasibility of predicting postoperative lung cancer recurrence and survival time using preoperative chest CT scans. However, further validation using larger, multisite cohort is necessary to ensure robustness and facilitate integration into clinical practice for improved cancer management.

CT-derived body composition associated with lung cancer recurrence after surgery

OBJECTIVES

To evaluate the impact of body composition derived from computed tomography (CT) scans on postoperative lung cancer recurrence.

METHODS

We created a retrospective cohort of 363 lung cancer patients who underwent lung resections and had verified recurrence, death, or at least 5-year follow-up without either event. Five key body tissues and ten tumor features were automatically segmented and quantified based on preoperative whole-body CT scans (acquired as part of a PET-CT scan) and chest CT scans, respectively. Time-to-event analysis accounting for the competing event of death was performed to analyze the impact of body composition, tumor features, clinical information, and pathological features on lung cancer recurrence after surgery. The hazard ratio (HR) of normalized factors was used to assess individual significance univariately and in the combined models. The 5-fold cross-validated time-dependent receiver operating characteristics analysis, with an emphasis on the area under the 3-year ROC curve (AUC), was used to characterize the ability to predict lung cancer recurrence.

RESULTS

Body tissues that showed a standalone potential to predict lung cancer recurrence include visceral adipose tissue (VAT) volume (HR = 0.88, p = 0.047), subcutaneous adipose tissue (SAT) density (HR = 1.14, p = 0.034), inter-muscle adipose tissue (IMAT) volume (HR = 0.83, p = 0.002), muscle density (HR = 1.27, p < 0.001), and total fat volume (HR = 0.89, p = 0.050). The CT-derived muscular and tumor features significantly contributed to a model including clinicopathological factors, resulting in an AUC of 0.78 (95% CI: 0.75-0.83) to predict recurrence at 3 years.

CONCLUSIONS

Body composition features (e.g., muscle density, or muscle and inter-muscle adipose tissue volumes) can improve the prediction of recurrence when combined with clinicopathological factors.

MRI features and whole-lesion apparent diffusion coefficient histogram analysis of brain metastasis from non-small cell lung cancer for differentiating epidermal growth factor receptor mutation status

AIM

To explore the utility of magnetic resonance imaging (MRI) characteristics and whole-lesion apparent diffusion coefficient histogram analysis of brain metastasis from non-small cell lung cancer (NSCLC) in the differentiation of epidermal growth factor receptor (EGFR) mutation status.

MATERIALS AND METHODS

Forty-eight patients with brain metastases from NSCLC were enrolled in this retrospective study. Patients were subtyped into EGFR mutation (23 cases) and wild-type (25 cases) groups. Whole-lesion histogram metrics were derived from the apparent diffusion coefficient (ADC) maps, and imaging features were evaluated according to conventional MRI. Student's t-test or Mann-Whitney U-test, chi-squared test, and receiver operating characteristic (ROC) curve analysis were performed to discriminate the two groups and to determine the diagnostic efficacy of ADC histogram parameters.

RESULTS

EGFR mutation group had more multiple brain metastases, less peritumoural brain oedema (PTBO), and lower peritumoural brain oedema index (PTBO-I) than EGFR wild-type group (all p<0.05). In addition, 90th and 75th percentiles of ADC and maximum ADC in the EGFR mutation group were significantly higher than in the EGFR wild-type group (all p<0.05). Ninetieth percentile of ADC had the highest area under the curve (AUC; 0.711), and it was found to outperform 75th percentile of ADC (AUC, 0.662; p=0.039) and maximum ADC (AUC, 0.681).

CONCLUSIONS

Whole-lesion ADC histogram analysis and MRI features of brain metastasis from NSCLC are expected to be potential biomarkers to non-invasively differentiate the EGFR mutation status.

Clinicopathologic characteristics and prognostic impact of atypical EGFR mutations in completely resected lung adenocarcinoma

INTRODUCTION

This study evaluated the clinicopathologic characteristics and prognostic impact of atypical epidermal growth factor receptor (EGFR) mutations in patients with completely resected lung adenocarcinoma (LUAD) and investigate whether adjuvant chemotherapy could benefit the survival outcomes for these subjects.

MATERIAL AND METHODS

We retrospectively reviewed resected LUAD samples from 8437 patients and identified 5358 EGFR-mutated (EGFRm) cases. Of these, 4847 had classical mutations, while 511 had atypical mutations. For further survival analysis, propensity score matching, Kaplan-Meier curve, and Cox regression analyses were conducted.

RESULTS

Of the 511 patients with atypical EGFRm LUAD, 131 patients had compound mutations. The frequency of exon 20 insertion (20-ins), G719X, L861Q, S768I, and de novo T790M were 30.3%, 32.7%, 21.9%, 9.2%, and 11.4%, respectively. These patients included a higher proportion of males than those with classical EGFRm LUAD. Between the 483 matched pairs of the classical and atypical EGFRm patients, no significant difference emerged in disease-free survival (DFS) (p = 0.476). Patients with the L861Q mutation had the poorest DFS among those with atypical EGFRm LUAD (p = 0.005). Cox regression analyses revealed that the L861Q mutation was an independent prognostic factor for DFS in 487 patients with solely atypical EGFRm LUAD. In addition, adjuvant chemotherapy did not improve the DFS for those patients, whether in stage IB (p = 0.638) or II-III (p = 0.505) of the disease.

CONCLUSION

The L861Q mutation is an independent prognostic factor for DFS in patients with atypical EGFRm LUAD after complete resection who would not benefit from adjuvant chemotherapy regardless of disease stage.

[A Review on Pathological High-risk Factors and Postoperative Adjuvant Chemotherapy in Stage IA Lung Adenocarcinoma]

The survival rate needs to be improved in early stage non-small cell lung cancer patients. The risk of recurrence is relatively high in invasive adenocarcinoma patients with a solid or micropapillary component, lymphovascular invasion or tumor spread through air spaces. Systemic treatment options including radical surgical resection should be explored for this population. Adjuvant chemotherapy is not recommended for patients in stage IA in current guidelines. This article is a review on the research progress of the above pathological high-risk factors and the role of adjuvant chemotherapy in patients with pathological high-risk factors in stage IA lung adenocarcinoma.
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Prognostic impact of pretreatment T790M mutation on outcomes for patients with resected, EGFR-mutated, non-small cell lung cancer

Background

Many previous studies have demonstrated that minor-frequency pretreatment T790M mutation (preT790M) could be detected by ultrasensitive methods in a considerable number of treatment-naïve, epidermal growth factor receptor (EGFR)-mutated, non-small cell lung cancer (NSCLC) cases. However, the impact of preT790M in resected cases on prognosis remains unclear.

Methods

We previously reported that preT790M could be detected in 298 (79.9%) of 373 surgically resected, EGFR-mutated NSCLC patients. Therefore, we investigated the impact of preT790M on recurrence-free survival (RFS) and overall survival (OS) in this cohort by multivariate analysis. All patients were enrolled from July 2012 to December 2013, with follow-up until November 30, 2017.

Results

The median follow-up time was 48.6 months. Using a cutoff value of the median preT790M allele frequency, the high-preT790M group (n = 151) had significantly shorter RFS (hazard ratio [HR] = 1.51, 95% confidence interval [CI]: 1.01–2.25, P = 0.045) and a tendency for a shorter OS (HR = 1.87, 95% CI: 0.99–3.55, P = 0.055) than the low-preT790M group (n = 222). On multivariate analysis, higher preT790M was independently associated with shorter RFS (high vs low, HR = 1.56, 95% CI: 1.03–2.36, P = 0.035), irrespective of advanced stage, older age, and male sex, and was also associated with shorter OS (high vs low, HR = 2.16, 95% CI: 1.11–4.20, P = 0.024) irrespective of advanced stage, older age, EGFR mutation subtype, and history of adjuvant chemotherapy.

Conclusions

Minor-frequency, especially high-abundance of, preT790M was an independent factor associated with a poor prognosis in patients with surgically resected, EGFR-mutated NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09869-7.

A nomogram for predicting brain metastases of EGFR-mutated lung adenocarcinoma patients and estimating the efficacy of therapeutic strategies

Background

To establish a nomogram for predicting the outcome of EGFR-mutated lung adenocarcinoma patients with brain metastases (BMs) and to estimate the efficacy of different therapeutic strategies.

Methods

The data of 129 cases with BM from the period between January 1st 2011 and December 31st 2014 were collected, and all of the cases were pathologically confirmed to be lung adenocarcinoma, stages I–IV and with 19 and/or 21 exon mutations of EGFR. Cox regression analysis and log-rank test were used for data analysis. The nomogram was used to establish the progression models.

Results

In the univariate analysis, the stage, ECOG score, interval between the diagnosis of lung cancer and BM, the number of brain metastatic lesions, and the diameter of the maximal brain metastatic lesion correlated well with overall survival (OS). In multivariate Cox proportional hazard analysis, the ECOG score, interval between the diagnosis of lung cancer and BM, and the number of brain metastatic lesions correlated well with the OS. Patients were divided into the poor prognostic group and the good prognostic group based on the nomogram prognostic model score. Subgroup analysis showed that in the poor prognostic group, the OS of patients who received radiotherapy was better than that of the patients who did not receive radiotherapy as the first-line treatment (30 vs. 19 months, P<0.05). The OS was 30 months in the TKI subgroup and 21 months in the no TKI subgroup, but no statistical difference was found (P>0.05). Patients in the good prognostic group who received radiotherapy had a better 3-y OS rate than the patients who received no radiotherapy as the first-line treatment (91.2% vs. 58.1%, P<0.05). The 3-y OS rate was 87.6% in the TKI subgroup and 67.8% in the no TKI group (P<0.05).

Conclusions

We established an effective nomogram model to predict the progression of EGFR-mutated lung adenocarcinoma patients with BM and the therapeutic effect of the individual treatments. Radiotherapy was beneficial for the patients of both the poor and good prognostic groups, but TKI may be better suited for treating the patients with good prognosis.

Genomic Profiling and Prognostic Value Analysis of Genetic Alterations in Chinese Resected Lung Cancer With Invasive Mucinous Adenocarcinoma

Background

Invasive mucinous adenocarcinoma (IMA) of the lung is a distinct histological subtype with unique clinical and pathological features. Despite previous genomic studies on lung IMA, the genetic characteristics and the prognosis-related biomarkers in Chinese surgically resected lung IMA remain unclear.

Methods

We collected 76 surgically resected primary tumors of invasive lung adenocarcinoma, including 51 IMA and 25 non-mucinous adenocarcinomas (non-IMA). IMA was further divided into pure-IMA (mucinous features≥90%) and mixed-IMA subgroups. Comprehensive genomic profiling based on targeted next-generation sequencing (NGS) of 425 genes was explored and genomic characteristics were evaluated for the correlation with postoperative disease-free survival (DFS).

Results

IMA had a unique genetic profile, with more diverse driver mutations and more tumor drivers/suppressors co-occurrence than that of non-IMA. The frequency of EGFR (72.0% vs. 40.0% vs. 23.1%, p=0.002) and ALK (undetected vs. 20.0% vs. 26.9%, p=0.015) alterations showed a trend of gradual decrease and increase from non-IMA to mixed-IMA to pure-IMA, respectively. The frequency of KRAS mutations in pure-IMA was higher than that in mixed-IMA, albeit statistically insignificant (23.1% vs. 4.0%, p=0.10). TP53 mutation was significantly less in pure-IMA compared to mixed-IMA and non-IMA (23.1% vs. 52.0% vs. 56.0%, p=0.03). Besides, IMA exhibited less arm-level amplifications (p=0.04) and more arm-level deletions (p=0.004) than non-IMA, and the frequency of amplification and deletion also showed a trend of gradual decrease and increase from non-IMA to mixed-IMA to pure-IMA, respectively. Furthermore, prognosis analysis in stage III IMA patients showed that patients harboring alterations in EGFR (mDFS=30.3 vs. 16.0 months, HR=0.19, P=0.027) and PI3K pathway (mDFS=36.0 vs. 16.0 months, HR=0.12, P=0.023) achieved prolonged DFS, while patients with poorly differentiated tumors (mDFS=14.1 vs. 28.0 months, HR=3.75, p=0.037) or with KRAS mutations (mDFS=13.0 vs. 20.0 months, HR=6.95, p=0.027) had shorter DFS. Multivariate analysis showed that KRAS mutations, PI3K pathway alterations, and tumor differentiation status were independent factors that have statistically significant influences on clinical outcomes of IMA patients.

Conclusion

Our study provided genomic insights into Chinese surgically resected lung IMA. We also identified several genomic features that may serve as potential biomarkers on postoperative recurrence in IMA patients with stage III disease.

Prognostic analysis of patients with non-small cell lung cancer harboring exon 19 or 21 mutation in the epidermal growth factor gene and brain metastases

Background

In 1997, the Radiation Therapy Oncology Group (RTOG) put forward the recursive partitioning analysis classification for the prognosis of brain metastases (BMs), but this system does not take into account the epidermal growth factor receptor (EGFR) mutations. The aim of the study is to assess the prognosis of patients with EGFR-mutated non-small cell lung cancer (NSCLC) and BMs in the era of tyrosine kinase inhibitor (TKI) availability.

Methods

This was a retrospective study of consecutive patients with EGFR-mutated (exon 19 or 21) NSCLC diagnosed between 01/2011 and 12/2014 at the Tianjin Medical University Cancer Institute & Hospital and who were ultimately diagnosed with BMs. The patients were stage I-III at initial presentation and developed BMs as the first progression. Overall survival (OS), OS after BM diagnosis (mOS), intracranial progression-free survival (iPFS), response to treatment, and adverse reactions were analyzed.

Results

Median survival was 35 months, and the 1- and 2- year survival rates were 95.6% (108/113) and 74.3% (84/113). The 3-month CR + PR rates of radiotherapy(R), chemotherapy(C), targeted treatment(T), and targeted treatment + radiotherapy(T+R) after BMs were 63.0% (17/27), 26.7% (4/15), 50.0% (7/14), and 89.7% (35/39), respectively. The median survival of the four treatments was 20, 9, 12, and 25 months after BMs, respectively (P = 0.001). Multivariable analysis showed that < 3 BMs (odds ratio (OR) = 3.34, 95% confidence interval (CI): 1.89–5.91, P < 0.001) and treatment after BMs (OR = 0.68, 95%CI: 0.54–0.85, P = 0.001) were independently associated with better prognosis.

Conclusions

The prognosis of patients with NSCLC and EGFR mutation in exon 19 or 21 after BM is associated with the number of brain metastasis and the treatment method. Targeted treatment combined with radiotherapy may have some advantages over other treatments, but further study is warranted to validate the results.

Genomic landscape of lung adenocarcinoma in East Asians

Lung cancer is the world's leading cause of cancer death and shows strong ancestry disparities. By sequencing and assembling a large genomic and transcriptomic dataset of lung adenocarcinoma (LUAD) in individuals of East Asian ancestry (EAS; n = 305), we found that East Asian LUADs had more stable genomes characterized by fewer mutations and fewer copy number alterations than LUADs from individuals of European ancestry. This difference is much stronger in smokers as compared to nonsmokers. Transcriptomic clustering identified a new EAS-specific LUAD subgroup with a less complex genomic profile and upregulated immune-related genes, allowing the possibility of immunotherapy-based approaches. Integrative analysis across clinical and molecular features showed the importance of molecular phenotypes in patient prognostic stratification. EAS LUADs had better prediction accuracy than those of European ancestry, potentially due to their less complex genomic architecture. This study elucidated a comprehensive genomic landscape of EAS LUADs and highlighted important ancestry differences between the two cohorts.

Positive EGFR mutation status is a risk of recurrence in pN0-1 lung adenocarcinoma when combined with pathological stage and histological subtype: A retrospective multi-center analysis

OBJECTIVES

Recurrence risk of resected lung adenocarcinoma is represented by pathological stage (pStage), histological subtype, and potentially by EGFR mutation. However, the relationship among these factors and their combined impact on prognosis are unclear.

MATERIALS AND METHODS

Using a multicenter database, we retrospectively investigated the prognostic impact of EGFR mutation status in relation to pStage and histological subtype in resected pN0-1M0 lung adenocarcinoma.

RESULTS

Among 1155 pN0-1M0 adenocarcinoma cases, pStage 0 and IA1-IB were confirmed predominantly in EGFR-positive cases. AIS, MIA, and lepidic predominant adenocarcinoma were also more frequently found in EGFR-positive cases and showed no/little recurrence regardless of EGFR mutation status. The 5-year recurrence-free survival (RFS) of papillary, acinar, solid, and micropapillary predominant adenocarcinoma was stratified by pStage (IA1-IB, IIA-IIIA) or histological malignant subtype (intermediate or high malignant subtype), and more finely subdivided by EGFR mutation status. Positive EGFR mutation cases showed worse RFS in both classifications. Low malignant subtype and pStage IA1-IB intermediate malignant subtype showed low frequency of recurrence. Whereas, in pStage IA1-IB high malignant subtype and pStage IIA-IIIA cases, EGFR-positive cases showed poorer 5-year RFS than EGFR-negative (49.6% and 75.6%, respectively, hazard ratio [HR] = 1.84, 95% CI = 1.38-7.42, p <  0.01) and multivariate analysis indicated positive EGFR mutation status was significantly related to poorer PRF (HR = 2.005, 95% CI = 1.029-3.906, p =  0.041).

CONCLUSION

EGFR mutation harbored primarily in early-stage or low-malignant histological subtypes with no/little recurrence. In pN0-1M0 adenocarcinoma with higher risk of recurrence, positive EGFR mutation cases showed worse RFS. EGFR mutation status enables better stratification of recurrence risk when considering pStage and histological malignant subtype.

The prognostic implications of EGFR mutation and ALK rearrangement for the long-term outcomes of patients with resected lung adenocarcinomas

Background

To investigate the prognostic impact of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement for the overall survival (OS) of patients with surgically treated lung adenocarcinomas.

Methods

A total of 689 patients with stage I–III lung adenocarcinomas (male:female = 334:355; median age, 64 years) underwent complete surgical resection between 2007 and 2013. The prognostic impact of EGFR mutation and ALK rearrangement on OS was analyzed using Cox regression analysis. Certain clinicopathological prognostic factors (i.e., age, sex, smoking status, nodule type, solid portion size, pathologic stage, adenocarcinoma subtype, and history of adjuvant chemotherapy) were included for adjustments of the hazard ratio (HR).

Results

EGFR mutation was observed in 438 patients (64%) and ALK rearrangement was seen in 28 patients (4%). Multivariable‐adjusted Cox regression demonstrated that the prognostic effect of EGFR mutation on OS differed by age (HR, exp.[−5.199 + 0.064^*age]). The adjusted HR for EGFR mutation was 0.14 (95% CI: 0.05–0.36; P < 0.001) at 50 years, 0.26 (95% CI: 0.15–0.46; P < 0.001) at 60 years, and 0.50 (95% CI: 0.31–0.81; P = 0.005) at 70 years. However, the effect of ALK rearrangement on OS was without statistical significance (P > 0.05).

Conclusions

EGFR mutation was independently prognostic of the long‐term outcomes of patients with surgically treated lung adenocarcinomas. A more favorable prognostic effect was seen in younger than in older patients. ALK rearrangement was not associated with OS.

A Comprehensive Meta-Analysis of Association between EGFR Mutation Status and Brain Metastases in NSCLC

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation have different clinicopathological characteristics compared with EGFR wild type NSCLC. A growing number of studies focused on the relevance between EGFR mutation status and brain metastases (BM) in NSCLC, but it remains controversial. Therefore, this study performed a comprehensive meta-analysis to untangle this issue. Several electronic databases including Pubmed, Embase, Web of science and Cochrane database were thoroughly searched. The odds ratio (OR) with 95% confidence interval (95%CI) was pooled to evaluate the relevance. Meta-regression analysis and subgroup analysis were conducted according to the heterogeneity. A total of 26 studies were identified finally in this meta-analysis. The overall OR was 1.58 (95%CI: 1.36-1.84), which indicated that EGFR mutation had a positive association with BM of NSCLC. The subgroup analysis resulted from eleven studies with lung adenocarcinoma revealed a higher possibility of BM in NSCLC with EGFR mutation compared with EGFR wild (p < 0.05). There was no significant difference in the risk of BM between NSCLC EGFR exon 19 mutation and exon 21 point mutation (p = 0.23). This meta-analysis suggests that EGFR mutation can be a risk factor for BM in NSCLC.

The impact of epidermal growth factor receptor mutations on the prognosis of resected non-small cell lung cancer: a meta-analysis of literatures

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation represents a good response to EGFR-tyrosine kinase inhibitor and an advantageous prognostic factor in advanced-stage non-small cell lung cancer (NSCLC). However, the predictive value of EGFR mutation for prognosis in NSCLC patients after complete surgery, which more reflective of natural process, remains controversial. We sought to examine the predictive value of EGFR mutation in NSCLC. Several studies with small sample sizes have been reported but small studies bring bias especially in a postoperative setting. Therefore, we sought to pool all current evidence to show the true effects.

METHODS

Electronic databases were used to search the relevant articles. Disease-free survival (DFS), which will be less effected by subsequent treatments after recurrence, was the primary endpoint. The DFS between EGFR mutated and wild-type patients were compared focus on stage I patients who are rarely received adjuvant therapy. Besides, the DFS of patients with 19 exon deletion (19del) and 21 exon L858R mutation (L858R) were compared. A random effects model was used.

RESULTS

A total of 19 relevant studies which involved 4,872 cases were enrolled and 2,086 patients were EGFR-mutated. The majority of studies used PCR-based methods to detect EGFR mutations. Through meta-analysis, we observed the DFS of EGFR-mutated patients were similar to wild type patients in overall population (HR 0.93, 95% CI: 0.74 to 1.17). Similar results were observed in stage I subgroup (HR 0.82, 95% CI: 0.50 to 1.33). DFS of 19 del patients were potentially inferior to L858R patients but the difference was not significant (HR 1.38, 95% CI: 0.76 to 2.52).

CONCLUSIONS

There was no significant difference in postoperative DFS between EGFR-mutant patients and wild-type with resected NSCLC. In addition, there is still insufficient evidence to support different postoperative treatment strategies (especially for stage I) for both mutated and wild-type patients. However, 19 del may be a negative factor, which may require more strict management. Thus, we strongly encourage reporting specific prognostic impacts of different mutation types.

EGFR mutations are significantly associated with visceral pleural invasion development in non-small-cell lung cancer patients

OBJECTIVES

A retrospective study was performed to investigate the association between EGFR mutations and visceral pleural invasion (VPI), and evaluate the prognostic value of EGFR in resected non-small-cell lung cancer (NSCLC) patients with VPI.

MATERIALS AND METHODS

Clinicopathological characteristics and follow-up information were collected from 508 consecutive patients with surgically resected stage I-III NSCLC, and EGFR mutations were detected based on real-time PCR technology. Significant results (P<0.05) from univariate logistic regression analysis were involved as covariates to adjust confounding factors in the analysis of independent factors.

RESULTS

VPI and EGFR mutations were detected in 229 (45.1%) and 243 (47.8%) cases in NSCLC, respectively. There was a significant association between EGFR mutations and VPI development. Both 19-del (adjusted OR =2.13, 95%CI =1.13-3.99, P=0.019) and L858R (adjusted OR =2.89, 95%CI =1.59-5.29, P=0.001) could significantly increase the risk of VPI development compared with EGFR wild-type. Higher frequency of L858R (adjusted OR =2.63, 95%CI =1.42-4.88, P=0.002) was detected in VPI patients compared with non-VPI patients. 19-del (adjusted HR =0.31, 95%CI =0.12-0.80, P=0.015) was an independent prognostic factor for a better disease-free survival (DFS) in non-VPI patients. No significant association was shown between EGFR mutations and DFS in VPI patients.

CONCLUSION

EGFR mutations were significantly associated with VPI development in NSCLC, but no significant association was observed between EGFR mutations and DFS in the patients with VPI. 19-del was a favorable prognostic factor for DFS in non-VPI patients.

The prognostic effect of the epidermal growth factor receptor gene mutation on recurrence dynamics of lung adenocarcinoma

OBJECTIVES

The prognostic effects of epidermal growth factor receptor (EGFR) gene mutation on lung adenocarcinoma recurrence have not been well established. The relationship between EGFR gene mutation and recurrence dynamics of lung adenocarcinoma was investigated.

METHODS

A total of 527 patients with complete resection for adenocarcinoma were reviewed retrospectively. EGFR gene mutation was analysed by polymerase chain reaction followed by bidirectional direct sequencing in recurred patients. Patients were divided into the EGFR gene mutation group (M) or the wild-type EGFR gene group (W). Recurrence types and disease-free intervals (DFIs) of the 2 groups were compared. DFIs were calculated by the Kaplan-Meier method and compared using the log-rank test and Cox proportional hazard model.

RESULTS

EGFR gene sequencing was performed in 115 recurrent adenocarcinoma patients. Sixty-six patients had EGFR mutations and 49 patients had wild-type EGFR. The median DFI of the 2 groups were significantly different (M: 20.3 months, W: 15.1 months, P = 0.012). EGFR gene mutation was the only prognostic factor for DFI [hazard ratio (HR) = 0.639, 95% confidence interval (CI) = 0.428-0.954, P = 0.029]. The proportion of loco-regional recurrences and distant metastases of both groups were similar (P = 0.50). In subgroup analysis, EGFR gene mutation (HR = 0.534, 95% CI = 0.339-0.839, P = 0.007) was a significant prognostic factor for DFI of distant metastases.

CONCLUSIONS

Lung adenocarcinoma with EGFR gene mutations had longer DFI than those with wild-type EGFR gene, especially with regard to distant metastasis. EGFR gene mutation was a prognostic factor for lung adenocarcinoma.

Increased risk of recurrence in resected EGFR-positive pN0M0 invasive lung adenocarcinoma

BACKGROUND

This study was conducted to evaluate the prognostic and recurrent impact of EGFR mutation status in resected pN0M0 lung adenocarcinoma with consideration of the histological subtype.

METHODS

Following retrospective analysis of whole 474 consecutive pathological N0M0 lung adenocarcinoma patients, the prognostic significance of EGFR mutation status was evaluated in limited 394 subjects. Overall survival and recurrence-free interval (RFI) were estimated using the Kaplan-Meier method and compared using a log-rank test. Univariate and multivariate analyses were performed using Cox proportional hazard models.

RESULTS

The five-year RFI was 85.7% and 93.3% for EGFR positive (n = 176) and negative (n = 218) cases, respectively (hazard ratio [HR] 1.992, 95% confidence interval [CI] 1.005-3.982; P = 0.048). Following the exclusion of specific subtypes free from recurrence or EGFR mutation (adenocarcinoma in situ, minimally invasive adenocarcinoma, and invasive mucinous adenocarcinoma), the five-year RFI was obviously poorer in EGFR positive compared to negative cases (80.7% and 92.1%, respectively; HR 2.163, 95% CI 1.055-4.341; P = 0.035). Multivariate analysis excluding the specific subtypes confirmed that male sex, age, current or Ex-smoking status, pleural invasion, and EGFR-positive status were independently associated with shorter RFI. No significant differences in five-year overall survival were found between the EGFR mutation positive and negative groups (88.7% and 93.7%, respectively; HR 1.630, 95% CI 0.787-3.432; P = 0.2).

CONCLUSION

EGFR mutations are associated with recurrence in pN0M0 lung adenocarcinoma. EGFR mutation status and histological subtype should be considered when evaluating the risk of recurrence in resected lung adenocarcinoma patients.

Prognostic value of EGFR and KRAS in resected non-small cell lung cancer: a systematic review and meta-analysis

Background

The prognostic value of EGFR and KRAS mutations in resected non-small cell lung cancer (NSCLC) has been reported. However, conflicting results were reported in these studies. The effect of mutations in these two genes in resected NSCLC remains controversial.

Methods

We searched Internet databases for studies reporting disease-free survival (DFS) and overall survival (OS) in resected NSCLC patients with EGFR or KRAS mutations. A meta-analysis calculating the pooled hazard ratio (HR) for DFS and OS was used to measure the association of EGFR or KRAS mutations with the prognosis of patients after surgery.

Results

A total of 9,635 patients from 32 studies were included in this analysis. The combined HR for EGFR mutations on DFS was 0.77 (95% CI 0.66–0.90, p=0.001) and on OS was 0.72 (95% CI 0.66–0.80, p<0.00001). In addition, the combined HR for KRAS mutations on DFS was 1.5 (95% CI 1.15–1.96, p=0.002) and on OS was 1.49 (95% CI 1.28–1.73, p<0.00001). Sensitivity analysis, subgroup analysis, and bias analysis proved the stability of the results.

Conclusion

The analysis showed that EGFR mutations were significantly associated with DFS and OS. These findings indicated that surgically treated NSCLC patients with EGFR mutations were inclined to exhibit a prolonged DFS and OS. In addition, the results indicated that KRAS mutations predicted worse DFS and OS in patients with resected NSCLC.

Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology

CONTEXT

- In 2013, an evidence-based guideline was published by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology to set standards for the molecular analysis of lung cancers to guide treatment decisions with targeted inhibitors. New evidence has prompted an evaluation of additional laboratory technologies, targetable genes, patient populations, and tumor types for testing.

OBJECTIVE

- To systematically review and update the 2013 guideline to affirm its validity; to assess the evidence of new genetic discoveries, technologies, and therapies; and to issue an evidence-based update.

DESIGN

- The College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology convened an expert panel to develop an evidence-based guideline to help define the key questions and literature search terms, review abstracts and full articles, and draft recommendations.

RESULTS

- Eighteen new recommendations were drafted. The panel also updated 3 recommendations from the 2013 guideline.

CONCLUSIONS

- The 2013 guideline was largely reaffirmed with updated recommendations to allow testing of cytology samples, require improved assay sensitivity, and recommend against the use of immunohistochemistry for EGFR testing. Key new recommendations include ROS1 testing for all adenocarcinoma patients; the inclusion of additional genes ( ERBB2, MET, BRAF, KRAS, and RET) for laboratories that perform next-generation sequencing panels; immunohistochemistry as an alternative to fluorescence in situ hybridization for ALK and/or ROS1 testing; use of 5% sensitivity assays for EGFR T790M mutations in patients with secondary resistance to EGFR inhibitors; and the use of cell-free DNA to "rule in" targetable mutations when tissue is limited or hard to obtain.

Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology

CONTEXT

In 2013, an evidence-based guideline was published by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology to set standards for the molecular analysis of lung cancers to guide treatment decisions with targeted inhibitors. New evidence has prompted an evaluation of additional laboratory technologies, targetable genes, patient populations, and tumor types for testing.

OBJECTIVE

To systematically review and update the 2013 guideline to affirm its validity; to assess the evidence of new genetic discoveries, technologies, and therapies; and to issue an evidence-based update.

DESIGN

The College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology convened an expert panel to develop an evidence-based guideline to help define the key questions and literature search terms, review abstracts and full articles, and draft recommendations.

RESULTS

Eighteen new recommendations were drafted. The panel also updated 3 recommendations from the 2013 guideline.

CONCLUSIONS

The 2013 guideline was largely reaffirmed with updated recommendations to allow testing of cytology samples, require improved assay sensitivity, and recommend against the use of immunohistochemistry for EGFR testing. Key new recommendations include ROS1 testing for all adenocarcinoma patients; the inclusion of additional genes (ERBB2, MET, BRAF, KRAS, and RET) for laboratories that perform next-generation sequencing panels; immunohistochemistry as an alternative to fluorescence in situ hybridization for ALK and/or ROS1 testing; use of 5% sensitivity assays for EGFR T790M mutations in patients with secondary resistance to EGFR inhibitors; and the use of cell-free DNA to "rule in" targetable mutations when tissue is limited or hard to obtain.

Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology

CONTEXT

In 2013, an evidence-based guideline was published by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology to set standards for the molecular analysis of lung cancers to guide treatment decisions with targeted inhibitors. New evidence has prompted an evaluation of additional laboratory technologies, targetable genes, patient populations, and tumor types for testing.

OBJECTIVE

To systematically review and update the 2013 guideline to affirm its validity; to assess the evidence of new genetic discoveries, technologies, and therapies; and to issue an evidence-based update.

DESIGN

The College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology convened an expert panel to develop an evidence-based guideline to help define the key questions and literature search terms, review abstracts and full articles, and draft recommendations.

RESULTS

Eighteen new recommendations were drafted. The panel also updated 3 recommendations from the 2013 guideline.

CONCLUSIONS

The 2013 guideline was largely reaffirmed with updated recommendations to allow testing of cytology samples, require improved assay sensitivity, and recommend against the use of immunohistochemistry for EGFR testing. Key new recommendations include ROS1 testing for all adenocarcinoma patients; the inclusion of additional genes (ERBB2, MET, BRAF, KRAS, and RET) for laboratories that perform next-generation sequencing panels; immunohistochemistry as an alternative to fluorescence in situ hybridization for ALK and/or ROS1 testing; use of 5% sensitivity assays for EGFR T790M mutations in patients with secondary resistance to EGFR inhibitors; and the use of cell-free DNA to "rule in" targetable mutations when tissue is limited or hard to obtain.

Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and recorded, and at the end of experiments, tumor xenografts were removed for Western blot and immunohistochemical analyses. Compared to control groups (negative control, regular-dose icotinib [IcoR], high-dose icotinib [IcoH], and docetaxel [DTX]) and regular icotinib dose (60 mg/kg) with docetaxel, treatment of mice with a high-dose (1200 mg/kg) of icotinib plus sequential docetaxel for 3 weeks (IcoH-DTX) had an additive effect on suppression of tumor xenograft size and volume (P < 0.05). Icotinib-containing treatments markedly reduced phosphorylation of EGFR, mitogen activated protein kinase (MAPK), and protein kinase B (Akt), but only the high-dose icotinib-containing treatments showed an additive effect on CD34 inhibition (P < 0.05), an indication of reduced microvessel density in tumor xenografts. Moreover, high-dose icotinib plus docetaxel had a similar effect on mouse weight loss (a common way to measure adverse reactions in mice), compared to the other treatment combinations. The study indicate that the high dose of icotinib plus sequential docetaxel (IcoH-DTX) have an additive effect on suppressing the growth of wild-type EGFR NSCLC cell nude mouse xenografts, possibly through microvessel density reduction. Future clinical trials are needed to confirm the findings of this study.

Prognostic implication of EGFR gene mutations and histological classification in patients with resected stage I lung adenocarcinoma

Introduction

The prognostic value of epidermal growth factor receptor (EGFR) mutations and the correlation between EGFR mutations and the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histological classification remain controversial. The current study aimed to investigate the pure prognostic role of EGFR mutations in treatment-naïve patients with resected stage I lung adenocarcinoma.

Methods

We retrospectively reviewed 373 patients with stage I pulmonary non-small-cell lung cancer who underwent complete surgical resection between January 2010 and May 2014. The tumors were classified according to IASLC/ATS/ERS criteria. EGFR mutation status was determined by established methods.

Results

A total of 120 patients were included for analysis; 87 had tumors with EGFR mutations and 33 had wild-type tumors. More low- and intermediate-grade tumors had EGFR mutations, and nearly half of the high-grade tumors were wild-type (75.7% versus 46.2%, p = 0.041). Patients with low-grade tumors had significantly greater median disease-free survival (DFS) (76.8 versus 13 months, p < 0.0001) and better overall survival (OS) (median OS not reached, p = 0.0003) than those with intermediate- and high-grade tumors. Tumor recurrence was 41.4% and 30.3% in mutant and wild-type patients. The 5-years survival rate was 54% and 71.2%. Multivariate analysis revealed that the new histological classification and the pathologic stage were independent predictors of both DFS and OS. EGFR mutation status had no prognostic implications.

Conclusion

Low grade tumors according to IASLC/ATS/ERS histological classification and the pathologic stage IA tumors of resected stage I lung adenocarcinomas independently predict better DFS and OS. EGFR mutations were frequently seen in histologically low- and intermediate-grade tumors but not a prognostic factor.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prognostic impacts of EGFR mutation status and subtype in patients with surgically resected lung adenocarcinoma

OBJECTIVE

Epidermal growth factor receptor (EGFR) gene mutation status is a well-established predictor of the efficacy of EGFR tyrosine-kinase inhibitor (TKI) therapy in patients with non-small cell lung cancer. Recently, differences in EGFR mutation subtypes have been reported to be associated with the efficacy of EGFR-TKI therapy. The prognostic impact of EGFR mutation status and subtypes remains controversial, however.

METHODS

We retrospectively reviewed 939 patients with surgically resected adenocarcinomas who underwent EGFR mutation status analysis between January 2010 and December 2014. Overall survival (OS) and recurrence-free survival (RFS) were compared according to pathological stage, EGFR mutation status, and EGFR mutation subtype using the log-rank test. Independent prognostic factors for OS and RFS were identified by multivariate analysis using the Cox proportional hazards model.

RESULTS

The median duration of follow-up was 48 months. We found that positive EGFR mutation status was significantly associated with longer OS and RFS in all patients and was associated with longer OS in patients in pathological stage I; however, there were no significant differences in OS and RFS between patients with exon 21 L858R mutations and those with exon 19 deletions. In a Cox regression model for OS, EGFR mutation status was a significant prognostic factor that was independent of well-established prognostic factors, including age, pathological stage, vascular invasion, lymphatic permeation, and serum carcinoembryonic antigen level.

CONCLUSIONS

Positive EGFR mutation status is a favorable prognostic factor in patients with surgically resected lung adenocarcinomas; however, EGFR mutation subtype (exon 21 L858R mutation or exon 19 deletion) exhibits no prognostic impact.

Greater efficacy of chemotherapy plus bevacizumab compared to chemo- and targeted therapy alone on non-small cell lung cancer patients with brain metastasis

Control of non-small-cell lung cancer (NSCLC) with brain metastasis is clinically challenging. This study retrospectively evaluated the efficacy of different adjuvant therapies for 776 cases of advanced NSCLCs with brain metastasis who treated with chemotherapy, chemotherapy plus bevacizumab, tyrosine kinase inhibitor (TKI) alone, or supportive care. The median progression-free survival (mPFS) and median overall survival (mOS) of patients treated with chemotherapy plus bevacizumab were 8.5 and 10.5 months, respectively, which were better than those of patients treated with other three therapies(P < 0.01). For patients with EGFR-mutated NSCLC, the efficacy of TKI treatment was not statistically better than that of chemotherapy plus bevacizumab but was significantly better than that of other therapies. Moreover, for patients with EGFR wild-type NSCLC, the mPFS and mOS after chemotherapy plus bevacizumab were greater than those with other two therapies (P < 0.01). The local response rate (RR)and disease control rate (DCR)with regimen including pemetrexed were greater than those with regimen including paclitaxel (P < 0.05). Chemotherapy plus bevacizumab was more effective for NSCLC patients with brain metastasis. Further studies will investigate the benefit of TKI alone for patients with EGFR-mutated. For patients with EGFR wild-type, chemotherapy plus bevacizumab did improve PFS and OS. Furthermore, regimens including pemetrexed led to a greater RR.

Differences among lesions with exon 19, exon 21 EGFR mutations and wild types in surgically resected non-small cell lung cancer

The clinical behavior of patients with advanced non-small cell lung cancer (NSCLC) differ between epidermal growth factor receptor (EGFR) exon 19 deletion (Ex19) and EGFR exon 21 L858R mutation (Ex21). This study aimed to evaluate whether these differences exist in surgically resected NSCLC. A total of 198 patients with surgically resected NSCLC harbouring Ex19 (n = 53), Ex21 (n = 51), and EGFR wild-type (Wt) (n = 94) were analyzed. The clinicopathological features, laboratory parameters, recurrent sites and disease-free survival (DFS) were compared according to mutational EGFR status. Ex21 occurred more frequently in female (p < 0.001), never-smokers (p < 0.001), adenocarcinoma (p < 0.001), low grade (p = 0.013) than Wt lesions. Ex19 occurred more frequently in female (p = 0.016), never-smokers (p = 0.008), adenocarcinoma (p < 0.001), low grade (p = 0.025) than Wt lesions. Ex 21 lesions (p = 0.026) had larger lepidic components than Wt lesions. Wt lesions had larger mucinous variant components than Ex21 lesions (p = 0.045) and Ex19 lesions (p = 0.015). Ex21 lesions were associated with lower pretreatment neutrophil: lymphocyte ratio (NLR) than Wt lesions (p = 0.017). The recurrent sites and DFS were similar among patients with Wt, Ex19 and Ex21.

Screening for major driver oncogene alterations in adenosquamous lung carcinoma using PCR coupled with next-generation and Sanger sequencing methods

We investigated the frequency of major driver oncogenes in lung adenosquamous cell carcinoma (ASC) cases. Frequency of EGFR, K-Ras, B-Raf, PIK3CA, DDR2, ALK, and PDGFRA gene mutations was examined in 56 patients using next-generation sequencing, polymerase chain reaction, and Sanger sequencing. Macrodissection or microdissection was performed in 37 cases to separate the adenomatous and squamous components of ASC. The overall mutation rate was 64.29%, including 55.36%, 7.14%, and 1.79% for EGFR, K-Ras, and B-Raf mutations, respectively. PIK3CA mutation was detected in three cases; all involved coexisting EGFR mutations. Of the 37 cases, 34 were convergent in two components, while three showed EGFR mutations in the glandular components and three showed PIK3CA mutations in the squamous components. With respect to EGFR mutations, the number of young female patients, nonsmokers, and those with positive pleural invasion was higher in the mutation-positive group than that in the mutation-negative. K-Ras mutation was significantly associated with smoking. Overall survival in the different EGFR mutation groups differed significantly. The frequency and clinicopathological characteristics of EGFR- and K-Ras-mutated adenosquamous lung carcinoma were similar to that noted in Asian adenocarcinomas patients. The high convergence mutation rate in both adenomatous and squamous components suggests monoclonality in ASC.

Efficacy and safety of icotinib as first-line therapy in patients with advanced non-small-cell lung cancer

Background and objective

Several clinical trials have proven that icotinib hydrochloride, a novel epidermal growth factor receptor (EGFR)–tyrosine kinase inhibitor, exhibits encouraging efficacy and tolerability in patients with advanced non-small-cell lung cancer (NSCLC) who failed previous chemotherapy. This study was performed to assess the efficacy and toxicity of icotinib as first-line therapy for patients with advanced pulmonary adenocarcinoma with EGFR-sensitive mutation.

Patients and methods

Thirty-five patients with advanced NSCLC with EGFR-sensitive mutation who were sequentially admitted to the First Affiliated Hospital of Xi’an Jiaotong University from March 2012 to March 2014 were enrolled into our retrospective research. All patients were administered icotinib as first-line treatment. The tumor responses were evaluated using Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1).

Results

Among the 35 patients, the tumor objective response rate (ORR) and disease control rate were 62.9% (22/35) and 88.6% (31/35), respectively. The median progression-free survival was 11.0 months (95% confidence interval [CI]: 10.2–11.8 months), and median overall survival was 21.0 months (95% CI: 20.1–21.9 months). The most common drug-related toxicities were rashes (eleven patients) and diarrhea (nine patients), but these were generally manageable and reversible.

Conclusion

Icotinib monotherapy is effective and tolerable as first-line treatment for patients with advanced lung adenocarcinoma with EGFR-sensitive mutation.

Risk of brain metastasis reduced after erlotinib treatment in advanced pulmonary adenocarcinoma patients with sensitive EGFR mutation

Purpose

Brain metastasis (BM) is associated with impaired quality of life and increased mortality. The study aimed to compare BM risk after erlotinib administration and chemotherapy in stage IIIB/IV pulmonary adenocarcinoma patients harboring epidermal growth factor receptor (EGFR) mutation.

Patients and methods

Eligible patients underwent match pair process with matching factors, including age, sex, performance status score, first-line or second-line treatment, first-line chemotherapy regimen (for the second-line treatment subgroup), stage IIIB or IV, and genotypes of EGFR mutation. BM and mortality risk of both groups were recorded and compared.

Results

In total 129 matched pairs were included for analysis. During a median follow-up of 21.5 months, time to BM risk was longer and incidences of BM within 2 years were lower in patients who received erlotinib than chemotherapy in total population, as well as subgroups of first-line treatment, second-line treatment, stage IIIB, stage IV, exon 19 deletion mutation, and exon 21 L858R mutation. Similar overall survival time and 2-year survival rates were seen in two groups totally or in any subgroup. Multivariate analysis showed that BM was retarded in patients who received erlotinib administration (hazard ratio, 1.695; P=0.001) and in patients who were in stage IIIB (hazard ratio, 1.751; P=0.001).

Conclusion

Erlotinib administration decreases BM risk in advanced pulmonary adenocarcinoma patients harboring sensitive EGFR mutations.

Analysis of Mutations in Epidermal Growth Factor Receptor Gene in Korean Patients with Non-small Cell Lung Cancer: Summary of a Nationwide Survey

Background:

Analysis of mutations in the epidermal growth factor receptor gene (EGFR) is important for predicting response to EGFR tyrosine kinase inhibitors. The overall rate of EGFR mutations in Korean patients is variable. To obtain comprehensive data on the status of EGFR mutations in Korean patients with lung cancer, the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists initiated a nationwide survey.

Methods:

We obtained 1,753 reports on EGFR mutations in patients with lung cancer from 15 hospitals between January and December 2009. We compared EGFR mutations with patient age, sex, history of smoking, histologic diagnosis, specimen type, procurement site, tumor cell dissection, and laboratory status.

Results:

The overall EGFR mutation rate was 34.3% in patients with non-small cell lung cancer (NSCLC) and 43.3% in patients with adenocarcinoma. EGFR mutation rate was significantly higher in women, never smokers, patients with adenocarcinoma, and patients who had undergone excisional biopsy. EGFR mutation rates did not differ with respect to patient age or procurement site among patients with NSCLC.

Conclusions

EGFR mutation rates and statuses were similar to those in published data from other East Asian countries.

[Research Progress of Mechanisms on Intracranial Metastasis of Non-small Cell Lung Cancer after Clinical Benefit from EGFR-TKI]

表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitor, EGFR-TKI）广泛用于治疗EGFR突变阳性的非小细胞肺癌（non-small cell lung cancer, NSCLC）。然而，部分患者在接受EGFR-TKI治疗后、原发病灶稳定甚至缩小的同时，却出现了新发颅内转移灶或者原有颅内病灶进展，其机制未明。近年来多项研究表明，这种现象可能与EGFR-TKI的药物代谢动力学、NSCLC原发灶与转移灶的异质性、EGFR突变本身特质及患者生存期的延长有关。因此，本文就NSCLC患者在EGFR-TKI治疗临床获益后发生颅内转移的相关机制研究进展作一综述。

Value of oncogenes for the prediction of brain metastases at initial diagnosis: a review of published data

Identifying cancer patients who are at high risk of developing brain metastases at initial diagnosis and applying effective intervention or monitoring strategies is of vital importance. Recent advances in the biology of brain metastases revealed that some oncogenes from primary tumors may be potential markers for identifying cancer patients likely to metastasize to the brain. We here summarize data on the mechanisms of brain metastases supporting the involvement of oncogene changes in the brain metastatic evolution. We also review the available evidence on clinical studies of oncogenes in the prediction of cancer patients with high incidence of brain metastases.

EGFR mutations as a prognostic and predictive marker in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) has entered the age of individual treatment, and increasing point mutations of specific oncogenes and rearrangement of some chromosomes are biomarkers used to predict the therapeutic effect of targeted therapy. At present, there is a consensus among clinicians that epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown favorable efficacy in NSCLC patients with EGFR mutation, and some relevant research has suggested that the presence of EGFR mutations is a favorable prognostic marker. However, the association of EGFR mutation status with the responsiveness to conventional chemotherapy agents and survival in NSCLC patients is still unclear. This review provides an overview of and assesses the role of EGFR as a prognostic marker for postoperative patients and as a predictive marker for response to cytotoxic chemotherapy. In addition, we review the comparison of response to chemotherapy between EGFR mutations in exon 19 and in exon 21 and the predictive role of p.T790M mutation.

Prognostic value of epidermal growth factor receptor mutations in resected non-small cell lung cancer: a systematic review with meta-analysis

BACKGROUND

The prognostic value of epidermal growth factor receptor (EGFR) mutations in resected non-small cell lung cancer (NSCLC) remains controversial. We performed a systematic review with meta-analysis to assess its role.

METHODS

Studies were identified via an electronic search on PubMed, Embase and Cochrane Library databases. Pooled hazard ratio (HR) for disease-free survival (DFS) and overall survival (OS) were calculated for meta-analysis.

RESULTS

There were 16 evaluated studies (n  =  3337) in the meta-analysis. The combined HR evaluating EGFR mutations on disease free survival was 0.96 (95% CI [0.79-1.16] P  =  0.65). The combined HR evaluating EGFR mutations on overall survival was 0.86 (95% CI [0.72-1.04] P  = 0.12). The subgroup analysis based on univariate and multivariate analyses in DFS and OS showed no statistically significant difference. There was also no statistically significant difference in DFS and OS of stage I NSCLC patients.

CONCLUSION

The systematic review with meta-analysis showed that EGFR mutations were not a prognostic factor in patients with surgically resected non-small cell lung cancer. Well designed prospective study is needed to confirm the result.

Aberrant large tumor suppressor 2 (LATS2) gene expression correlates with EGFR mutation and survival in lung adenocarcinomas

BACKGROUND

Large tumor suppressor 2 (LATS2) gene is a putative tumor suppressor gene with potential roles in regulation of cell proliferation and apoptosis in lung cancer. The aim of this study is to explore the association of aberrant LATS2 expression with EGFR mutation and survival in lung adenocarcinoma (AD), and the effects of LATS2 silencing in both lung AD cell lines.

METHODS

LATS2 mRNA and protein expression in resected lung AD were correlated with demographic characteristics, EGFR mutation and survival. LATS2-specific siRNA was transfected into four EGFR wild-type (WT) and three EGFR mutant AD cell lines and the changes in LATS2 expression and relevant signaling molecules before and after LATS2 knockdown were assayed.

RESULTS

Fifty resected lung AD were included (M:F=23:27, smokers:non-smokers=19:31, EGFR mutant:wild-type=21:29) with LATS2 mRNA levels showed no significant difference between gender, age, smoking and pathological stages while LATS2 immunohistochemical staining on an independent set of 79 lung AD showed similar trend. LATS2 mRNA level was found to be a significant independent predictor for survival status (disease-free survival RR=0.217; p=0.003; Overall survival RR=0.238; p=0.036). siRNA-mediated suppression of LATS2 expression resulted in augmentation of ERK phosphorylation in EGFR wild-type AD cell lines with high basal LATS2 expression, discriminatory modulation of Akt signaling between EGFR wild-type and mutant cells, and induction of p53 accumulation in AD cell lines with low baseline p53 levels.

CONCLUSIONS

LATS2 expression level is predictive of survival in patients with resected lung AD. LATS2 may modulate and contribute to tumor growth via different signaling pathways in EGFR mutant and wild-type tumors.

Brain metastases in lung adenocarcinoma: impact of EGFR mutation status on incidence and survival

Background

The brain represents a frequent progression site in lung adenocarcinoma. This study was designed to analyse the association between the epidermal growth factor receptor (EGFR) mutation status and the frequency of brain metastases (BM) and survival in routine clinical practice.

Patients and methods

We retrospectively analysed the medical records of 629 patients with adenocarcinoma in Slovenia who were tested for EGFR mutations in order to analyse the cumulative incidence of BM, the time from the diagnosis to the development of BM (TDBM), the time from BM to death (TTD) and the median survival.

Results

Out of 629 patients, 168 (27%) had BM, 90 patients already at the time of diagnosis. Additional 78 patients developed BM after a median interval of 14.3 months; 25.8 months in EGFR positive and 11.8 months in EGFR negative patients, respectively (p = 0.002). EGFR mutations were present in 47 (28%) patients with BM. The curves for cumulative incidence of BM in EGFR positive and negative patients demonstrate a trend for a higher incidence of BM in EGFR mutant patients at diagnosis (19% vs. 13%, p = 0.078), but no difference later during the course of the disease. The patients with BM at diagnosis had a statistically longer TTD (7.3 months) than patients who developed BM later (3.1 months). The TTD in EGFR positive patients with BM at diagnosis was longer than in EGFR negative patients (12.6 vs. 6.8, p = 0.005), while there was no impact of EGFR status on the TTD of patients who developed BM later.

Conclusions

Except for a non-significant increase of frequency of BM at diagnosis in EGFR positive patients, EGFR status had no influence upon the cumulative incidence of BM. EGFR positive patients had a longer time to CNS progression. While EGFR positive patients with BM at diagnosis had a longer survival, EGFR status had no influence on TTD in patients who developed BM later during the course of disease.

[Predictive role of EGFR mutation status on postoperative prognosis in patients with resected lung adenocarcinomas]

BACKGROUND

At present the proportion of lung adenocarcinomas in NSCLC is higher than before. Thus, the study on prognosis of lung adenocarcinoma is extremely important. The predictive value of epidermal growth factor receptor (EGFR) mutations for prognosis in patients with resected lung adenocarcinomas has not be reported in China. The aim of this study is to analyze the association between the EGFR mutations and the outcomes of patients with resected lung adenocarcinomas.

METHODS

Total of 301 patients with stage Ia-IIIa resected lung adenocarcinomas whose survival had been identified were retrospectively analyzed. Their EGFR mutations were detected by real-time quantitative PCR and DNA sequencing technology together.

RESULTS

The proportion of EGFR mutation was 52.5% (158/301). The 2-year (disease-free survival, DFS) of EGFR-mutant group and wild-type EGFR group was 76.8%, 83.0%; 5-year overall survival (OS) of them was 67.7%, 65.7%. There was no significant difference for two groups (P = 0.252, P = 0.715). Further analysis for subgroups shows that the 2-year DFS, 5-year OS of mutant group and wild-type group in stage I-II was similar. For the patients with stage IIIa, the median DFS, 2-year DFS in mutant group was 12.2 months, 21.1%, lower than the 22.2 months, 42.1% in wild-type group. But there was no significant difference for both groups (P = 0.584, P = 0.295). The median OS, 5-year OS was 34.0 months, 30.8% in mutant group, while 38.7 months, 22.9% in wild-type group. There was no significant difference for both groups (P = 0.907, P = 0.444).

CONCLUSIONS

EGFR-mutant group with resected lung adenocarcinomas has a tendency of lower DFS than the wild-type EGFR group only in stage IIIa, but there was no significant difference for both groups. The EGFR mutation status was not associated with disease-free survival or overall survival in resected lung adenocarcinomas.

Prognostic value of epidermal growth factor receptor mutations in resected lung adenocarcinomas

The purpose of this study was to evaluate the association between epidermal growth factor receptor (EGFR) mutations and prognosis in patients with completely resected lung adenocarcinoma. A total of 131 patients were included in this study. EGFR mutation status in exons 18-21 of the tyrosine kinase-binding domain was detected using nested PCR amplification of individual exon. The χ (2) test was used to analyze the associations between EGFR mutations and the different variables. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). EGFR mutations in 18-21 exons were detected in 58 of the 131 patients (44.3 %). Smoking status (P = 0.029), N stage (P = 0.021), and pathologic stage (P = 0.048) were significantly associated with EGFR mutations. The median DFS in mutant EGFR and wild-type EGFR groups was 36.6 and 25.7 months, respectively (P = 0.533). No significant correlation was observed between EGFR mutations and OS (P = 0.564). However, patients with exon 19 mutation tended to have longer DFS than those with exon 21 mutation (46.2 vs. 21.9 months, P = 0.056), and the 1-, 2-, and 3-year OS rates were significantly higher in patients with exon 19 mutation compared to patients with exon 21 mutation (100, 96.7, 93.3 vs. 91.3, 82.6, 60.9 %, respectively, P = 0.01). Our data demonstrated that EGFR mutations do not have significant prognostic value in primary resected lung adenocarcinomas, but patients with exon 19 mutation tended to have better prognostic value compared to patients with exon 21 mutation.

EGFR mutation status and its impact on survival of Chinese non-small cell lung cancer patients with brain metastases

Brain metastasis (BM) is a leading cause of death in patients with non-small cell lung cancer (NSCLC). EGFR mutations in primary NSCLC lesions have been associated with sensitivity to EGFR tyrosine kinase inhibitor (TKI). Therefore, it has become important to understand EGFR mutation status in BM lesions of NSCLC, and its clinical implications. BM samples of 136 NSCLC patients from South China, in which 15 had paired primary lung tumors, were retrospectively analyzed for EGFR mutation by amplification mutation refractory system (ARMS). Effect of BM EGFR mutations on progression-free survival (PFS) and overall survival (OS) was evaluated by Kaplan-Meier curves and log-rank test. EGFR mutations were detected in 52.9% (72 of 136) of the BM lesions, with preference in female and never-smokers. A concordance rate of 93.3% (14 of 15) was found between the primary NSCLC and corresponding BM. Positive prediction value of testing primary NSCLCs for BM EGFR mutation is 100.0 %, and negative prediction value is 87.5%. Median PFS of BM surgery was 12 and 10 months (P = 0.594) in the wild-type and mutant group, respectively. Median OS of BM surgery was 24.5 and 15 months (P = 0.248) in the wild-type and mutant group, respectively. In conclusion, EGFR mutation status is highly concordant between the primary NSCLC and corresponding BM. The primary NSCLC could be used as surrogate samples to predict EGFR mutation status in BM lesions or vice versa. Moreover, EGFR mutations showed no significant effect on PFS or OS of NSCLCs with BM.