Frequency of well-identified oncogenic driver mutations in lung adenocarcinoma of smokers varies with histological subtypes and graduated smoking dose

Deep sequencing of candidate genes identified 14 variants associated with smoking abstinence in an ethnically diverse sample

Despite the large public health toll of smoking, genetic studies of smoking cessation have been limited with few discoveries of risk or protective loci. We investigated common and rare variant associations with success in quitting smoking using a cohort from 8 randomized controlled trials involving 2231 participants and a total of 10,020 common and 24,147 rare variants. We identified 14 novel markers including 6 mapping to genes previously related to psychiatric and substance use disorders, 4 of which were protective (CYP2B6 (rs1175607105), HTR3B (rs1413172952; rs1204720503), rs80210037 on chr15), and 2 of which were associated with reduced cessation (PARP15 (rs2173763), SCL18A2 (rs363222)). The others mapped to areas associated with cancer including FOXP1 (rs1288980) and ZEB1 (rs7349). Network analysis identified significant canonical pathways for the serotonin receptor signaling pathway, nicotine and bupropion metabolism, and several related to tumor suppression. Two novel markers (rs6749438; rs6718083) on chr2 are flanked by genes associated with regulation of bodyweight. The identification of novel loci in this study can provide new targets of pharmacotherapy and inform efforts to develop personalized treatments based on genetic profiles.

Micropapillary and solid components as high-grade patterns in IASLC grading system of lung adenocarcinoma: Clinical implications and management

OBJECTIVES

The grading system proposed by the International Association for the Study of Lung Cancer is based on a combination of predominant histologic subtypes and the proportion of high-grade components with a cutoff of 20%. We aimed to examine the clinical implications of the grading system beyond the discrimination of patient prognosis, while assessing the biological differences among high-grade subtypes.

METHODS

We retrospectively reviewed 648 consecutive patients with resected lung adenocarcinomas and examined their clinicopathologic, genotypic, and immunophenotypic features and treatment outcomes. Besides the differences among grades, the clinical impact of different high-grade components: micropapillary (MIP) and solid (SOL) patterns, was individually evaluated.

RESULTS

Survival outcomes were well-stratified according to the grading system. Grade 3 tumors exhibited aggressive clinicopathologic features, while being an independent prognostic factor in multivariable analysis. A small proportion (<20 %) of high-grade components in grade 2 had a negative prognostic impact. The prognostic difference bordering on the 20 % cutoff of the MIP proportion was validated; however, the proportion of SOL component did not affect prognosis. A survival benefit from adjuvant chemotherapy was observed in grade 3 tumors regardless of histologic subtype, but not in grade 1-2 tumors. The molecular and immunophenotypic features were different among grades, but still heterogeneous in grade 3, with MIP harboring frequent EGFR mutation and SOL exhibiting high PD-L1 expression. The treatment outcome after recurrence was worse in grade 3, but tumors with MIP pattern had an equivalent prognosis to that of grade 1-2 tumors, reflecting the high frequency of molecular targeted therapy.

CONCLUSIONS

In addition to stratifying patient prognosis, the current grading system could discriminate clinical course, therapeutic effects of adjuvant chemotherapy, and molecular and immunophenotypic features. Further stratification based on biological heterogeneity in grade 3 remains necessary to enhance the role of the grading system in guiding patient management.

Exploring the molecular features and genetic prognostic factors of pulmonary high-grade neuroendocrine carcinomas

Molecular research on large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) has progressed significantly. However, there are still fewer molecular markers related to prognostic/therapeutic strategies for these conditions compared to those for adenocarcinoma. We therefore investigated the molecular characteristics of neuroendocrine carcinomas (NECs). We enrolled patients surgically diagnosed with NECs between 2011 and 2019, with complete follow-up records. All were analyzed using whole exome sequencing and p53/Rb immunohistochemistry (IHC). A total of 92 cases, comprising 45 pure SCLC, 15 combined SCLC, 27 pure LCNEC, and 5 combined LCNEC, were included. TP53 (78.3%) and RB1 (34.8%) were the most common molecular alterations, followed by KMT2D, LRP1B, FAT3, NCOR2, SPTA1, and NOTCH1. The mutation frequency for EGFR was 10.9%. Sixteen patients with LCNEC who had TP53/RB1 co-alterations were SCLC-like, while the remaining were NSCLC-like. There was no statistically significant difference between the groups regarding overall survival (OS; p = 0.458) and progression-free survival (PFS; p = 0.157). The frequency of the loss of Rb expression by IHC in SCLC-like LCNEC was 100%. Significant pathway alterations unique to SCLC included Notch and AMPK, while HIF-1 was enriched exclusively in LCNEC. NCOR2 mutation was linked to worse OS (p = 0.029) and PFS (p = 0.015), while wild-type SPTA1 was associated with poor PFS (p = 0.018). IHC for Rb was reliable for predicting LCNEC molecular subtypes, indicating its clinical value. NCOR2 and SPTA1 alterations were identified as prognostic factors that may provide therapeutic targets for patients with NEC.

Stromal micropapillary pattern and CD44s expression predict worse outcome in lung adenocarcinomas with micropapillary pattern

OBJECTIVES

This study aims to investigate the clinicopathologic characteristics of lung adenocarcinoma with micropapillary pattern (MPP) and the expression of CD44s and CD44v6 in MPP.

METHODS

A total of 202 patients diagnosed with primary lung adenocarcinoma with MPP were included. We estimated the proportion of MPP in each tumor tissue and divided MPP into aerogenous micropapillary pattern (AMP) and stromal micropapillary pattern (SMP). The expression of CD44s and CD44v6 was estimated by immunohistochemical staining. Clinicopathologic data were collected from the patients' medical records. We also collected patients' follow-up data and used PFS (progression-free survival) as a survival indicator.

RESULTS

Lung adenocarcinoma with MPP had a high risk of pleural invasion, lymph node metastasis, in advanced TNM stage, and a high rate of EGFR mutation. The presence of SMP indicated a higher rate of pleural invasion, lymphovascular invasion, lymph node metastasis, and a worse PFS compared with pure AMP. We found high expression of CD44s in micropapillary, especially in AMP, while the absence of CD44s expression indicated shorter survival, which was an independent unfavorable factor for PFS.

CONCLUSIONS

Lung adenocarcinoma with micropapillary pattern indicated an unfavorable prognosis, which had two different pattens, AMP and SMP. SMP indicated a worse survival than AMP, and was an independent unfavorable factor for PFS. So, AMP/SMP subclassification is necessary to evaluate patient's prognosis. Furthermore, the absent expression of CD44s in micropapillary indicated shorter survival, especially in patients with EGFR mutation. Herein, CD44s may be a biological marker for micropapillary lung adenocarcinoma.

Comprehensive analyses unveil novel genomic and immunological characteristics of micropapillary pattern in lung adenocarcinoma

Lung adenocarcinoma (LUAD) usually contains heterogeneous histological subtypes, among which the micropapillary (MIP) subtype was associated with poor prognosis while the lepidic (LEP) subtype possessed the most favorable outcome. However, the genomic features of the MIP subtype responsible for its malignant behaviors are substantially unknown. In this study, eight FFPE samples from LUAD patients were micro-dissected to isolate MIP and LEP components, then sequenced by whole-exome sequencing. More comprehensive analyses involving our samples and public validation cohorts on the two subtypes were performed to better decipher the key biological and evolutionary mechanisms. As expected, the LEP and MIP subtypes exhibited the largest disease-free survival (DFS) differences in our patients. EGFR was found with the highest mutation frequency. Additionally, shared mutations were observed between paired LEP and MIP components from single patients, and recurrent mutations were verified in the Lung-Broad, Lung-OncoSG, and TCGA-LUAD cohorts. Distinct biological processes or pathways were involved in the evolution of the two components. Besides, analyses of copy number variation (CNV) and intratumor heterogeneity (ITH) further discovered the possible immunosurveillance escape, the discrepancy between mutation and CNV level, ITH, and the pervasive DNA damage response and WNT pathway gene alternations in the MIP component. Phylogenetic analysis of five pairs of LEP and MIP components further confirmed the presence of ancestral EGFR mutations. Through comprehensive analyses combining our samples and public cohorts, PTP4A3, NAPRT, and RECQL4 were identified to be co-amplified. Multi-omics data also demonstrated the immunosuppression prevalence in the MIP component. Our results uncovered the evolutionary pattern of the concomitant LEP and MIP components from the same patient that they were derived from the same initiation cells and the pathway-specific mutations acquired after EGFR clonal mutation could shape the subtype-specificity. We also confirmed the immunosuppression prevalence in the MIP subtype by multi-omics data analyses, which may have resulted in its unfavorable prognosis.

ERBB2 mutation landscape in non-small cell lung cancer patients in Northeast China

OBJECTIVE

This study aimed to explore erb-b2 receptor tyrosine kinase 2 (ERBB2) gene mutations in patients with non-small cell lung cancers (NSCLC) in Northeast China, and to analyze ERBB2 mutation subtypes and clinicopathological characteristics related to the presence of ERBB2 mutations.

METHODS

In this study, 1087 tissue samples, 368 whole blood samples, and 68 pleural effusion samples from 1349 NSCLC were collected. Next-generation sequencing (NGS) was used to perform genetic testing on the samples. The proportion of patients with ERBB2 mutations and related clinicopathological characteristics were analyzed.

RESULTS

The mutation rate of ERBB2 in NSCLC was 5.58% (85/1523). Of the patients with ERBB2 mutations, 27.63% (21/76) were over 65 years old, 59.21% (45/76) were women, and 68.42% (52/76) were non-smokers. The majority of tumors were adenocarcinomas (92.1%, 70/76) and stage III and IV diseases accounted for 81.58% (62/76) of all cases. There were 14 subtypes of ERBB2 mutations; the most frequently seen were ERBB2 copy number alteration (41.76%, 38/91) and ERBB2 exon 20 in-frame insertion (36.26%, 33/91). Of the patients with ERBB2 mutations, 24 had concurrent epidermal growth factor receptor mutations, seven had mesenchymal epithelial transition factor amplifications, and three had anaplastic lymphoma kinase mutations. The agreement between tissue and paired blood samples in the presence of ERBB2 mutations was 64.3% (9/14).

CONCLUSION

ERBB2 mutations in Northeast China NSCLC patients have a unique molecular spectrum. Our work can provide guidance for the clinical diagnosis and treatment of patients with ERBB2 mutations in Northeast China.

Single-cell analysis of somatic mutations in human bronchial epithelial cells in relation to aging and smoking

Although lung cancer risk among smokers is dependent on smoking dose, it remains unknown if this increased risk reflects an increased rate of somatic mutation accumulation in normal lung cells. Here, we applied single-cell whole-genome sequencing of proximal bronchial basal cells from 33 participants aged between 11 and 86 years with smoking histories varying from never-smoking to 116 pack-years. We found an increase in the frequency of single-nucleotide variants and small insertions and deletions with chronological age in never-smokers, with mutation frequencies significantly elevated among smokers. When plotted against smoking pack-years, mutations followed the linear increase in cancer risk until about 23 pack-years, after which no further increase in mutation frequency was observed, pointing toward individual selection for mutation avoidance. Known lung cancer-defined mutation signatures tracked with both age and smoking. No significant enrichment for somatic mutations in lung cancer driver genes was observed.

Correlation of Epidermal Growth Factor Receptor Mutation With Major Histologic Subtype of Lung Adenocarcinoma According to IASLC/ATS/ERS Classification

OBJECTIVE

Our prospective study aims to define the correlation of EGFR(epidermal growth factor receptor) mutations with major histological subtypes of lung adenocarcinoma from resected and non-resected specimens, according to the WHO 2015 classification, in Moroccan North East Population.

METHODS

Epidermal growth factor receptor mutations of 150 primary lung adenocarcinoma were performed using Real-Time PCR or SANGER sequencing. SPSS 21 was used to assess the relationship between histological subtypes of lung adenocarcinoma and EGFR mutation status.

RESULTS

25 mutations were detected in the series of 150 lung adenocarcinomas, most of which were found in cases with papillary, acinar, patterns than without these patterns and more frequently occurred in the cases without solid pattern than with this pattern. A significant correlation was observed between EGFR mutation and acinar (P = 0,024), papillary pattern (P = 0,003) and, negative association with a solid pattern (P < 0,001). In females, EGFR mutations were significantly correlated with the acinar pattern (P = 0,02), whereas in males with the papillary pattern (P = 0,01). Association between the histologic component and exon 19 deletions and exon 21 mutations were also evaluated and, we found a significant correlation between the papillary major pattern with exon 19 mutations (P = 0,004) and, ex21 with the acinar component (P = 0,03).

CONCLUSION

An analysis of resected and non-resected lung ADC specimens in 150 Moroccan Northeast patients, revealed that acinar and papillary patterns may predict the presence of a mutation in the EGFR gene. While the solid major pattern may indicate a low mutation rate of the EGFR gene.

Concomitant genetic alterations are associated with plasma D-dimer level in patients with non-small cell lung cancer

Objective: D-dimer is correlated to the poor prognosis of non-small cell lung cancer. The study aimed to investigate the association between plasma D-dimer and concomitant mutations in non-small cell lung cancer. Methods: A total of 517 non-small cell lung cancer patients were recruited and tested for ALK, BRAF, EGFR, HER2/ERBB2, KRAS, MET, PIK3CA, RET and ROS1 mutation by next-generation sequencing. Multiple gene mutation information, clinical baseline data and laboratory test data were analyzed statistically. Results: All patients were divided into three groups: wild-type group, single-gene mutation group and concomitant mutation group. The analysis of D-dimer, uric acid, gender, family history, smoking history, histology and distant metastasis all showed significant differences in the three groups (p < 0.05). D-dimer was considered as a risk factor for concomitant mutations according to the unordered multiple logistic regression analysis. The receiver operating characteristic curve analysis indicated that D-dimer had an important predictive value for the occurrence of concomitant mutations (AUC: 0.94; sensitivity: 88.71%; specificity: 86.46). There was significantly shorter median progression-free survival in the concomitant mutation group compared with the single mutation group (7.70 months vs 14.00 months; p = 0.0133). Conclusion: Plasma D-dimer is significantly associated with concomitant mutations and may be regarded as a potent predictor of concomitant mutations for non-small cell lung cancer patients.

The Prognostic Value of Non-Predominant Micropapillary Pattern in a Large Cohort of Resected Invasive Lung Adenocarcinoma Measuring ≤3 cm

The aim of this study was to analyze the influence of non-predominant micropapillary pattern in small sized invasive lung adenocarcinoma. A total of 986 lung adenocarcinoma patients with tumor size ≤3 cm were identified and classified according to the IALSC/ATS/ERS classification. Emphasis was placed on the impact of non-predominant micropapillary pattern on disease-free survival (DFS) and overall survival (OS). The relationship between lung adenocarcinoma subtype and lymph node involvement, EGFR mutation and KRAS mutation was also evaluated. A nomogram was developed to predict the probability of 3- and 5-year OS for these patients. The concordance index and calibration plot were used to validate this model. Among all 986 patients, the percentages of lymph node involvement were: 58.1, 50.0, 33.5, 21.4, 21.1, 10.9, 0, and 0% for micropapillary predominant, solid predominant, acinar predominant, papillary predominant, invasive mucinous adenocarcinoma (IMA), lepidic predominant, minimally invasive adenocarcinoma (MIA), adenocarcinoma in situ (AIS), respectively. The frequency of EGFR mutation in the cases of lepidic predominant, acinar predominant, MIA, micropapillary predominant, papillary predominant, solid predominant, IMA, and AIS were 51.1, 45.2, 44.4, 36.8, 29.3, 26.8, 8.3, and 0%, respectively. A non-predominant micropapillary pattern was observed in 344 (38.4%) invasive adenocarcinoma (IAC), and its presence predicted a poorer DFS (median: 56.0 months vs. 66.0 months, P <0.001) and OS (median: 61.0 months vs. 70.0 months, P <0.001). After propensity score matching, non-predominant micropapillary pattern retained its unfavorable effect on DFS (P = 0.007) and OS (P = 0.001). Multivariate analysis showed that non-predominant micropapillary pattern was identified as an independent prognostic factor for DFS (P = 0.003) and OS (P <0.001) in IAC. The nomogram showed good calibration and reliable discrimination ability (C-index = 0.775) to evaluated the 3- and 5-year OS. This retrospective analysis of patients with small sized IAC suggests the value of non-predominant micropapillary pattern to predict poor prognosis. A reliable nomogram model was constructed to provide personalized survival predictions.

Comprehensive molecular analysis of genomic profiles and PD-L1 expression in lung adenocarcinoma with a high-grade fetal adenocarcinoma component

Background

Fetal adenocarcinoma of the lung is a rare variant of lung adenocarcinoma and is subcategorized into low-grade and high-grade (H-FLAC) fetal adenocarcinoma. We previously reported poor prognosis in pulmonary adenocarcinomas with an H-FLAC component; however, the genetic abnormalities involved in H-FLAC remain unclear. Therefore, this study aimed to elucidate molecular abnormalities as potential therapeutic targets for H-FLACs.

Methods

We performed immunohistochemical analysis and comprehensive genetic analyses using whole-exome sequencing in 16 lung cancer samples with an H-FLAC component. DNA was extracted from formalin-fixed paraffin-embedded tissues after macrodissection of the H-FLAC component.

Results

Cancer-related mutations were identified in TP53 (7/16 cases), KMT2C (6/16 cases), KRAS (4/16 cases), NF1 (3/16 cases), STK11 (3/16 cases), CTNNB1 (2/16 cases), and EGFR (1/16 cases). A high tumor mutation burden of ≥10 mutations per megabase was observed in 3/16 cases. A high microsatellite instability was not detected in any case. Based on the cosine similarity with the Catalogue of Somatic Mutations in Cancer mutational signatures, H-FLACs were hierarchically clustered into three types: common adenocarcinoma-like (five cases), surfactant-deficient (ten cases), and signatures 2 and 13-related (one case). All common adenocarcinoma-like cases presented thyroid transcription factor-1 (TTF-1) expression, whereas surfactant-deficient cases often presented loss of TTF-1 and surfactant protein expression and included cases with mutations in the surfactant system genes NKX2-1 and SFTPC. H-FLACs displayed low programmed death ligand-1 (PD-L1) expression (1–49% of tumor cells) in 5/16 cases, and no case displayed high PD-L1 expression (≥50% of tumor cells).

Conclusions

This study indicates that lung cancers with an H-FLAC component rarely harbor currently targetable driver gene mutations for lung cancer but display a high frequency of KMT2C mutations. The microsatellite instability, tumor mutation burden, and PD-L1 expression status suggest a poor response to immune checkpoint therapy.

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.

Genetic profile of non-small cell lung cancer (NSCLC): A hospital-based survey in Jinhua

Background

We describe the clinical features, genetic profile, and their correlation in NSCLC patients.

Methods

A total of 256 Chinese patients with NSCLC were enrolled in this study. NGS‐based genomic profiling of major lung cancer‐related genes was performed on formalin‐fixed paraffin‐embedded tumor samples.

Results

Of 256 patients with NSCLC, 219 were adenocarcinoma and most of them were in the early stage. Among patients, 63.3% patients have more than two gene mutations. By analyzing variant allele frequency (VAF), we found that the median VAF has significant differences between squamous cell carcinoma and adenocarcinoma, as well as early stage and advanced stage. The frequency of mutations in EGFR, MET, and RET were significantly higher in nonsmokers than in smokers. Besides, Pearson correlation analysis found that ALK, BRAF, and MET mutations had a strong correlation with age. Notably, higher frequencies of ALK and BRAF alterations were associated with younger age, while more frequent MET mutations appear in the patients at age 55 or older.

Conclusion

More unique features of cancer driver genes in Chinese NSCLC were identified by next‐generation sequencing. These findings highlighted that it is necessary to carry out targeted detection according to different clinical features for NSCLC.

Association of histologic subtypes with genetic alteration and PD-L1 expression in pulmonary adenocarcinoma

Genetic alteration and programmed death-ligand 1 (PD-L1) expression have been revealed to be associated with various subtypes of pulmonary adenocarcinoma (ADC). The present study aimed to explore the association between histological subtypes and genetic alterations and PD-L1 expression. A total of 375 cases of pulmonary ADC were included. Genetic alterations were determined using next generation sequencing (NGS) in 136 cases. PD-L1 expression was detected by immunohistochemistry (based on clone 22C3) in the remaining 239 cases. Mutations in the epidermal growth factor receptor gene (EGFR) were detected in 76 (55.8%) cases associated with the papillary subtype (P=0.038). Mutations in the Kirsten rat sarcoma viral oncogene homolog gene (KRAS) were present in 46 (33.8%) cases associated with the lepidic subtype (P<0.001) and mucinous ADC (P=0.037). PD-L1 expression was identified in 63 (26.4%) cases associated with the solid subtype (P<0.001). In conclusion, the present study demonstrated that EGFR and KRAS mutations, alongside PD-L1 protein expression are significantly associated with specific subtypes of pulmonary ADC. These results should aid our ability to accurately select appropriate areas of the heterogeneous tumor for molecular testing methods and to predict patient outcomes and prognosis.

Prognostic value and therapeutic implications of expanded molecular testing for resected early stage lung adenocarcinoma

OBJECTIVES

This study aimed to evaluate the prognostic and potential therapeutic value of expanded molecular testing of resected early-stage lung ACA.

METHODS

We analyzed 324 patients who underwent lobectomy and lymphadenectomy for clinical Stage I&II lung ACA between 2011-2017. Molecular testing was routinely performed, first by PCR-based Sanger sequencing and FISH and then expanded to a 20 and then 50-gene next generation sequencing (NGS) panel. The frequency of mutations by testing method and their association with disease-free (DFS) and overall survival (OS) were tested.

RESULTS

A total of 241 patients (74.4%) had at least one somatic mutation detected, with KRAS exon 2 (38.1%) and EGFR (17.9%) being the most common. TP53 was the most frequent co-existing mutation. Detection of at least one mutation increased from 49% with selective PCR/FISH testing to 82% with limited NGS/FISH, and 91% with extended NGS/FISH (p < 0.001). The rate of actionable mutations increased from 18% to 32% and 45% with expansion of molecular testing, respectively (p = 0.001). Using NGS, an additional 10 cases with EGFR mutations, and other rare mutations were found, including BRAF (5.9%), MET (5.6%), ERBB2 (4.1%), PIK3CA (2.3%), and DDR2 (2.1%). The expansion of FISH testing resulted in one additional detection of ROS1 and RET (1%) rearrangement. KRAS mutation was associated with worse DFS (HR 1.87; 95%CI 1.14-3.06) and OS (HR 2.09; 95%CI 1.11-3.92). BRAF mutation detected in NGS tested patients was also associated with decreased DFS (HR3.80; 95%CI 1.46-9.89) and OS (HR 7.37; 95%CI 2.36-22.99) on multivariate analysis.

CONCLUSION

The expansion of molecular testing has resulted in a substantial increase in the detection of potentially therapeutically significant mutations in resected early-stage ACA. KRAS and BRAF mutation status by NGS was prognostic for relapse and survival. These data emphasize opportunities for clinical trials in a growing number surgical ACA patients with available targeted therapies.

Actionable Mutation Profiles of Non-Small Cell Lung Cancer patients from Vietnamese population

Comprehensive profiling of actionable mutations in non-small cell lung cancer (NSCLC) is vital to guide targeted therapy, thereby improving the survival rate of patients. Despite the high incidence and mortality rate of NSCLC in Vietnam, the actionable mutation profiles of Vietnamese patients have not been thoroughly examined. Here, we employed massively parallel sequencing to identify alterations in major driver genes (EGFR, KRAS, NRAS, BRAF, ALK and ROS1) in 350 Vietnamese NSCLC patients. We showed that the Vietnamese NSCLC patients exhibited mutations most frequently in EGFR (35.4%) and KRAS (22.6%), followed by ALK (6.6%), ROS1 (3.1%), BRAF (2.3%) and NRAS (0.6%). Interestingly, the cohort of Vietnamese patients with advanced adenocarcinoma had higher prevalence of EGFR mutations than the Caucasian MSK-IMPACT cohort. Compared to the East Asian cohort, it had lower EGFR but higher KRAS mutation prevalence. We found that KRAS mutations were more commonly detected in male patients while EGFR mutations was more frequently found in female. Moreover, younger patients (<61 years) had higher genetic rearrangements in ALK or ROS1. In conclusions, our study revealed mutation profiles of 6 driver genes in the largest cohort of NSCLC patients in Vietnam to date, highlighting significant differences in mutation prevalence to other cohorts.

Co-occurring genetic alterations predict distant metastasis and poor efficacy of first-line EGFR-TKIs in EGFR-mutant NSCLC

PURPOSE

To determine the frequency of co-occurring genes in non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation and the predictive effect of co-mutations on the efficacy of EGFR tyrosine kinase inhibitors (EGFR-TKIs).

METHODS

54 patients with advanced NSCLC were tested for 422 clinically relevant genes by next-generation sequencing (NGS) before treatment. Among them, patients with EGFR mutation received first-line treatment of EGFR-TKIs. Progression-free survival (PFS) and objective response rate (ORR) were evaluated using Kaplan-Meier methods and compared between two groups using log-rank test.

RESULTS

Among 24 EGFR mutant and 30 EGFR wild-type patients, co-mutation rate was lower in patients with EGFR mutation (62.5% [15/24] vs 93.3% [28/30], p = 0.005). There was lower frequency for co-alterations in BRAF (0% [0/24] vs 20% [7/30], p = 0.033), NF1 (4.2% [1/24] vs 30% [9/30], p = 0.038) and RAS-RAF-MAPK pathway genes (16.6% [4/24] vs 56.7% [17/30], p = 0.003) in EGFR mutation group. 24 patients with EGFR mutation received first-line treatment of gefitinib or erlotinib, with an ORR of 83.3% and a median PFS of 12.3 months (95% CI 10.00-14.60). Co-mutation was associated with shorter median PFS (10.2 months [95% CI 5.20-15.20] vs 15.3 months [95% CI 12.09-15.81]; HR 0.29 [95% CI 0.10-0.82]; p = 0.014) in EGFR mutation cohort. Among patients with EGFR mutation and distant metastasis, median PFS was decreased in those with co-mutations (6.3 months [95% CI 3.25-9.35] vs 22.0 months[95% CI 12.10-31.90]; HR 0.12 [95% CI 0.00-5.87]; p = 0.007) and frequency of PIK3CA (0% [0/12] vs 41.7% [5/12], p = 0.037) and PI3K/AKT/mTOR pathway genes (0% [0/12] vs 50% [6/12], p = 0.014) was lower.

CONCLUSION

The presence of co-mutations was lower in the EGFR mutation patients and reduces the efficacy of EGFR-TKI, especially in patients with distant metastases. Lower frequency of co-mutation in PIK3CA and PI3K/AKT/mTOR pathway genes may be responsible for promoting metastasis and limiting the efficacy of EGFR-TKIs.

Association between the novel classification of lung adenocarcinoma subtypes and EGFR/KRAS mutation status: A systematic literature review and pooled-data analysis

OBJECTIVES

This study aims to determine the association of EGFR/KRAS mutation status with histological subtypes of lung adenocarcinoma (LAC) based on the IASLC/ATS/ERS classification.

METHODS

Pubmed and Cochrane databases were searched from January 2011 to June 2018 for studies that included patients with LAC who underwent surgical resection were classified according to the new IASLC/ATS/ERS classification. EGFR/KRAS status assessment was requireded. The primary outcome was determined by the odds ratio (OR) of the incidence of mutation status of certain of each histological subtype. The reference group consisted of EGFR/KRAS mutation negative patients.

RESULTS

Twenty-seven eligible studies involving 9022 patients with mutation gene detection were included for analysis. Among them, 6717 (74.5%) patients were from the Asian region and, 2305 (25.5%) patients were from Non-Asian regions. The most prevalent subtype was acinar (34.7%), followed by papillary (22.9%), lepidic (18.9%), solid (13.6%), micropapillary (6.3%), and invasive mucinous adenocarcinoma (3.5%). EGFR mutations were more common in patients with resected lepidic predominant adenocarcinoma (OR,1.76; 95%CI, 1.38-2.24;p < 0.01) and were rarely found in solid predominant adenocarcinoma (OR,0.28; 95%CI, 0.23-0.34;p < 0.01) or IMA (OR,0.10; 95%CI, 0.06-0.14;p < 0.01). Conversely, KRAS mutations were characterized by IMA (OR,7.01; 95%CI, 5.11-9.62;p < 0.01), and were less frequently identified in lepidic (OR,0.58; 95%CI, 0.45-0.75;p < 0.01) and acinar (OR,0.65; 95%CI, 0.55-0.78;p < 0.01) predominant subtypes. Further analyses were performed in Asian and Non-Asian groups and the results were consistent.

CONCLUSIONS

The current study confirms that the IASLC/ATS/ERS classification is associated with driver gene alterations in resected LAC.

Thick-wall cavity predicts worse progression-free survival in lung adenocarcinoma treated with first-line EGFR-TKIs

BACKGROUND

Cavity occurs in 5.7 to 14.9% of patients with lung adenocarcinoma (ADC). However, the impact of cavity on the therapeutic response to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in ADC patients with EGFR mutations remains unclear. The aim of the present retrospective study was to elucidate the incidence and detailed characteristics of EGFR-mutant cavitary ADC and investigate the efficacy of EGFR-TKI treatment in this subgroup.

METHODS

Two hundred seventy-six consecutive patients with advanced EGFR-mutant lung ADC treated with first-line EGFR-TKIs were enrolled. Cavitation and the thickness of cavity wall were assessed based on high-resolution computed tomography scans. Progression-free survival (PFS) was analyzed by the Kaplan-Meier plots and the log-rank test was used to calculate the significance between groups.

RESULTS

Cavity occurred in 5.4% (15/276) of patients with EGFR-mutant lung ADC and was more prevalent among male patients (66.7% vs. 33.3%, P = 0.008). Of the 15 EGFR-mutant cavitary ADC, 9 patients had exon 19 deletion (19DEL) and 6 harbored L858R mutation, 9 patients had thick-wall cavity while 6 had thin-wall cavity. Cavity had an adverse impact on the PFS of EGFR-mutant ADC treated with first-line EGFR-TKIs (noncavity versus cavity, 11.0 versus 6.5 months, hazard ratio [HR]: 0.33, 95% confidence interval [CI], 0.15-0.73, P = 0.003). The impaired effect was only observed in patients with L858R mutation (11.0 vs. 4.2 months, HR: 0.05, 95%CI, 0.01-0.27, P = 0.0003) but not in those with 19DEL (10.4 versus 9.7 months, HR: 0.73, 95%CI, 0.30-1.75, P = 0.483). All six L858R-mutant cavitary ADC patients had thick-wall cavity while thick-wall cavity was only identified in one thirds (3/9) of patients with 19DEL. Further analyses showed that patients with thick-wall cavity had worse PFS (6.0 versus 11.0 months, P = 0.013). Multivariate analysis identified cavity as an independent predictive factor for PFS (HR: 0.49, 95% CI, 0.26-0.90, P = 0.022).

CONCLUSION

Cavitary ADC was associated with a worse PFS of first-line EGFR-TKI therapy, mainly in those with L858R mutation. Thick-wall cavity formation may be the main cause that contribute to the worse PFS.

Lepidic, Papillary Components and EGFR Mutations are Frequent in Patients With Lung Adenocarcinoma Who are Over 75 Years Old

Treatment for lung adenocarcinoma frequently diverges from standard treatment in older patients. Clinical, pathologic, and molecular characteristics of lung cancer in patients over 75 years old have not been fully described. The aim of our work was to describe the rate of EGFR, KRAS, BRAF, and HER2 mutations, and ALK rearrangement and pathologic characteristics in patients with lung adenocarcinoma over 75, compared with patients below 75 years old. This is a retrospective study from 2 cohorts: a histopathologic cohort of all consecutively resected lung adenocarcinoma in our institution for patients over 75 (n=54, from 2006 to 2017) compared with patients below 75 years old (n=148, from 2014 to 2017) and a molecular cohort of all stage IIIb or IV lung adenocarcinoma from 2009 to 2017 (n=1611). Papillary and lepidic components were more frequently found in patients over 75 years old (P=0.046 and 0.0078, respectively). The rate of current smokers was lower in older patients (P<0.0001). EGFR mutations were more frequent in patients over 75 than in younger patients: 17% versus 8.1% (P<0.0001). The mutually exclusive KRAS mutation was more frequent in patients below 75 years old than in older patients: 25.8% versus 12.8% (P<0.0001). There was no difference for the proportion of the 2 most frequent EGFR mutations (exon 19 deletion and L858R mutation) (P=0.85) or KRAS-mutated codon (P=0.22) between tumors in younger or older patients. There was no statistically significant difference for the presence of BRAF, HER2 mutations, and ALK rearrangement (P=0.44, 0.71, and 1, respectively). Our work highlights the fact that EGFR mutations are more frequent in patients over 75 years old in our population. We can hypothesize that this difference might be mainly caused by the less frequent occurrence of tobacco-smoking-related lung cancers in the elderly and the presence of a lepidic or papillary component in this age group.

Lung cancer in never smokers-the East Asian experience

Approximately one third of all lung cancer patients in East Asia are never-smokers. Furthermore, the proportion of lung cancer in never smokers (LCINS) has been increasing over time. Never-smokers are more often diagnosed with adenocarcinoma in East Asia, a subtype largely defined by oncogenic drivers. In this subgroup of patients, as high as 90% of patients have been found to harbor well-known oncogenic mutations and can be successfully managed with targeted therapies inhibiting specific oncogenic mutant kinases. EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment has been the most important targeted therapy in lung adenocarcinoma from East Asian never-smokers as approximately 70% of these patients have the opportunity to receive EGFR-TKI treatment. Lung squamous cell carcinoma (SQCC) and small cell lung cancer (SCLC) are two common histologic types of smoking-related non-small cell lung cancer (NSCLC). The proportion of never-smokers with SQCC and SCLC in East Asian patients seems to be higher than that in Caucasian patients. Recent studies also suggest that lung SQCC and SCLC in never-smokers may be distinct subtypes. Therefore, better understanding of the biologic characteristics of these subtypes of patients may provide new insights for the treatment. In this review, we will provide an overview of East Asian experience in the treatment of advanced, never-smoking lung cancer, focusing on etiologic factors in the development of LCINS, targeted therapy for never-smokers with adenocarcinoma, distinct characteristics of never-smokers with lung SQCC and SCLC, and the role of immunotherapy in never-smokers with NSCLC.

HER2 mutations in Chinese patients with non-small cell lung cancer

Background

ERBB2 (HER2) is a driver gene identified in non-small cell lung cancer (NSCLC). The prevalence, clinicopathology, genetic variability and treatment of HER2-positive NSCLC in Chinese population are unclear.

Patients and Methods

Eight hundred and fifty-nine patients with pathologically confirmed NSCLC were screened for HER2 mutations using Sanger sequencing. Next-generation sequencing (NGS) was performed in positive cases. HER2 amplification was detected with FISH. Overall survival (OS) was evaluated using Kaplan-Meier methods and compared with log-rank tests.

Results

Twenty-one cases carrying HER2 mutations were identified with a prevalence of 2.4%. HER2 mutations were more frequently encountered in females, non-smokers and adenocarcinoma. NGS was performed in 19 out of 21 patients, The results showed 16 cases with additional genetic aberrations, most commonly associated with TP53 (n = 6), followed by EGFR (n = 3), NF1 (n = 3), KRAS (n = 2) and other mutations. One patient harbored HER2 amplification. Four patients with stage IV received afatinib treatment, and three showed stable disease with a median progression-free survival of 4 months and one patient was diagnosed with progressive disease.

Conclusion

HER2 mutations represent a distinct subset of NSCLC. NGS showed that HER2 mutations commonly co-existed with other driver genes. Afatinib treatment displayed moderate efficacy in patients with HER2 mutations.

Concurrent gene alterations with EGFR mutation and treatment efficacy of EGFR-TKIs in Chinese patients with non-small cell lung cancer

PURPOSE

We investigated the frequency of concurrent genes in EGFR-mutant non-small cell lung cancer patients and determined its value in predicting the efficacy of EGFR-TKIs treatment.

METHODS

Three hundred and twenty patients, who harbored EGFR activating mutations and received EGFR-TKIs treatment, were examined for another eight genes including KRAS, NRAS, PIK3CA, BRAF, and HER2 mutations and ALK, ROS1, and RET fusion genes based on reverse transcription PCR. Progression-free survival and overall survival with EGFR-TKIs treatment were evaluated using Kaplan-Meier methods and compared between different patients using log-rank tests.

RESULTS

Twenty-one (6.6%) of 320 EGFR mutant samples with additional gene alterations were identified. The most common concurrent gene was PIK3CA mutation (n = 9), followed by EML4-ALK rearrangement (n = 6), HER2 mutation (n = 3), RET rearrangement (n = 1), ROS1 rearrangement (n = 1) and KRAS mutation (n = 1). Patients with single EGFR mutation had a significantly longer progression-free survival than those with concurrent genes (10.9 vs. 6.0 months, P = 0.002). Among the 21 cases, patients with PIK3CA mutation had the longest median progression-free survival (7.6 months), followed by ALK rearrangement (5.0 months) and other gene types (1.2 months). No overall survival difference was found between patients with single EGFR mutation and concurrent gene alterations (21.0 vs.17.6 months, P = 0.17).

CONCLUSION

We demonstrated that concurrent gene alterations occurred in some patients with EGFR mutations. Concurrent gene alterations decreased the efficacy of EGFR-TKIs.

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.

Clinicopathologic characteristics of EGFR, KRAS, and ALK alterations in 6,595 lung cancers

BACKGROUND

EGFR, KRAS, and ALK alterations are major genetic changes found in non-small cell lung cancers (NSCLCs). Testing advanced lung adenocarcinoma tumors for these three genes is now standard care. The purpose of this study was to investigate the clinicopathologic expression pattern of these three genes in East Asian NSCLC patients.

PATIENTS AND METHODS

We conducted a retrospective study of all patients tested for mutations of these three genes at a single institute in Korea between 2006 and 2014. Study data were extracted from electronic medical records. Univariate and multivariate logistic regression analyses were used to measure associations between clinicopathologic features and alterations of EGFR, KRAS, and ALK.

RESULTS

We detected 12 EGFR-mutated tumors with additional mutations in KRAS (N=6, 0.1%) or ALK (N=6, 0.1%). General clinicopathologic characteristics of tumors with EGFR, KRAS, or ALK mutations were similar to previous reports. Patients having EGFR L858R point mutations were older than patients having EGFR exon 19 deletions. EGFR G719X point mutations were more common in men and smokers than exon 19 deletions or L858R point mutations. Tumors having KRAS G12C mutations were less often of mucinous type than those with G12D or G12V, mutations.

CONCLUSIONS

This is the largest three gene molecular epidemiology study in East Asian NSCLC patients. Each genetic alteration was associated with distinct clinicopathologic characteristics. Furthermore, different age and sex are associated with different subtypes of EGFR and KRAS mutations.

[Advances of the Role of Lung Cancer Driver Gene and PD-1/PD-L1 Pathway Interaction in the Tumorigenesis and Progression of Non-small Cell Lung Cancer]

程序性死亡分子1（programmed death 1, PD-1）/程序性死亡分子1配体（programmed death 1 ligand, PD-L1）通路是免疫调节的重要通路，而这一通路在肿瘤组织中存在着异常激活，提示PD-1/PD-L1通路可能参与了肿瘤的免疫逃逸过程。肿瘤驱动基因在非小细胞肺癌（non-small cell lung cancer, NSCLC）的发生发展中发挥着重要的作用，而对于肿瘤免疫逃逸的建立同样具有潜在的作用，这提示肿瘤驱动基因通路与PD-1/PD-L1通路可能存在相互作用。本文将对目前关于PD-L1与主要的肺癌驱动基因表皮生长因子受体基因（epidermal growth factor receptor, EGFR）、鼠类肉瘤病毒癌基因（Kirsten rate sarcoma viral oncogene homolog, KRAS）及棘皮微管样蛋白4-间变性淋巴瘤激酶融合基因（echinoderm microtubuleassociated protein-like 4 -anaplastic lymphoma kinase, EML4-ALK）之间的关系及调控进行综述，总结肺癌驱动基因及PD-1/PD-L1通路相互作用在非小细胞肺癌发生发展中的作用。

EGFR, KRAS, and BRAF mutational profiles of female patients with micropapillary predominant invasive lung adenocarcinoma

Background/aim: This study aimed to analyze EGFR, KRAS, and BRAF mutations in females with micropapillary predominant invasive lung adenocarcinoma and their relationships with immunohistochemical and clinicopathological patterns.Materials and methods: A total of 15 females with micropapillary lung adenocarcinoma were selected. Mutational analysis of the EGFR, KRAS, and BRAF genes was carried out. Information regarding the demographic data, tumor size, treatment, and survival time for each patient was collated, and the predominant cell type, secondary architectural growth patterns, psammoma bodies, necrosis, and visceral pleural and angiolymphatic invasions were evaluated.Results: We identified EGFR mutation in six cases, KRAS mutation in three cases, and BRAF mutation in one case. EGFR, c-kit, VEGFR, and bcl-2 positivity was observed in ten, seven, four, and six cases, respectively. All cases were positive for VEGF (strong positivity in 11 cases and weak positivity in four cases) and bcl-2 (strong positivity in nine cases and weak positivity in six cases). Seven (46.6%) cases were positive for c-kit and 10 (66.6%) cases were positive for EGFR. Conclusion: EGFR mutation occurred at a higher incidence rate in micropapillary predominant invasive adenocarcinoma than has previously been found in conventional lung adenocarcinomas. KRAS mutation was observed as having a similar frequency to what was previously observed, but the frequency of BRAF mutation was lower than previously reported.

Worldwide Frequency of Commonly Detected EGFR Mutations

CONTEXT

- Recurrent epidermal growth factor receptor ( EGFR) mutations are seen in a subset of pulmonary adenocarcinomas. These mutations are targeted by EGFR inhibitors and are a biomarker for response to EGFR inhibitor therapies. Initial data have indicated an increased frequency of activating EGFR mutations in nonsmoking Asian females. However, there are very few studies of global scope that address the question of mutation distribution across the population of lung cancer.

OBJECTIVE

- To determine the frequency of EGFR mutations in exons 18 through 21 detected in clinical laboratories participating in the College of American Pathologists proficiency testing program for EGFR in calendar year 2013.

DESIGN

- We reviewed the surveys from 170 clinical laboratories from 20 countries that participated in the College of American Pathologists EGFR proficiency testing program. The proficiency testing includes questions regarding the total numbers of tests performed at each common mutation site, including both activating and resistance mutations, and their frequency. Countries were grouped into regional groups in order to assess frequency of mutation by type, and to indirectly assess ethnic differences in mutation frequencies.

RESULTS

- Among the treatment-sensitive activating mutations, the most common are exon 19 mutations (n = 10 802 of 136 533 cases; 7.9% of total cases tested) and the exon 21 L858R mutation (n = 10 351 of 136 533 cases; 7.6% of total cases tested) and the least common are exon 20 mutations (n = 466 of 136 533 cases; 0.3% of total cases tested). The T790M mutation in exon 20 is the more common resistance mutation (n = 1010 of 136 533 cases; 0.7% of all cases tested). The highest activating mutation frequency is seen in southern Asia (n = 4260 of 9337 cases; 46%) and the lowest activating mutation frequencies are in South and North America (n = 113 of 1439 cases and 7926 of 86 654 cases; 8% and 9%, respectively).

CONCLUSIONS

- Our data confirm that activating EGFR mutations are more common in southern Asia and that the distribution of activating EGFR mutations varies significantly across the regions. Similarly, the frequency and distribution of resistance mutations also show significant variation when comparing southern Asia with other regions.

Accuracy of the cobas EGFR Mutation Assay in Non-small-cell Lung Cancer Compared With Three Laboratory-developed Tests

BACKGROUND

The reliability of the cobas EGFR assay to detect epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer (NSCLC) as an in vitro diagnostic test was compared with 3 laboratory-developed tests (LDTs).

MATERIALS AND METHODS

After screening for EGFR mutations using formalin-fixed-paraffin-embedded NSCLC tissue sections using the cobas EGFR assay, 151 samples were further tested with 3 LDTs; the peptide nucleic acid-locked nucleic acid polymerase chain reaction (PCR) clamp, PCR invader, and Cycleave assays. The cobas EGFR assay performance was evaluated by determining the concordance rate and κ-coefficient between the assays. In samples exhibiting discrepancies in the EGFR mutation status in the 4 assays, next-generation sequencing was performed to confirm mutated sequences.

RESULTS

Concordance rates and κ-coefficients between the cobas EGFR assay and the other tests were 96.0% and 0.921 for the peptide nucleic acid-locked nucleic acid PCR clamp assay, 94.0% and 0.881 for the PCR invader assay, and 96.7% and 0.934 for the Cycleave assay, respectively. Data showed very good agreement with the other assays. Precise mutated sequences or exons in the EGFR gene matched in 137 samples (90.7%). Different results were obtained in 4 samples (2.6%), owing to systemic limitations of the assay. Next-generation sequencing of 10 (6.6%) samples with discordant results exhibited a concordance rate of 60% to 80% in each assay.

CONCLUSIONS

The cobas EGFR assay showed high concordance rates and κ-coefficients between the 3 compared LDTs and can be used to select patients who would benefit from EGFR-tyrosine kinase inhibitors.

ALK and ROS1 rearrangements, coexistence and treatment in epidermal growth factor receptor-wild type lung adenocarcinoma: a multicenter study of 732 cases

Background

Anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) rearrangements represent two most frequent fusion targets in lung adenocarcinoma. Our study was intended to explore the clinicopathological characteristics, coexistence and treatment of ALK/ROS1-rearranged patients of lung adenocarcinoma without epidermal growth factor receptor (EGFR) mutation.

Methods

Patients with wild-type EGFR mutation were screened for ALK/ROS1 at four domestic hospitals. ALK/ROS1 rearrangements were detected by reverse transcription-polymerase chain reaction (RT-PCR). Progression-free survival (PFS) curve was plotted with the Kaplan-Meier method.

Results

Among 732 eligible cases, ALK and ROS1 rearrangements were detected in 89 (12.2%) and 32 (4.4%) patients respectively. One patient harbored coexisting ALK/ROS1 fusion. Both ALK and ROS1-positive phenotypes were predominantly detected in younger non-smokers. More ALK/ROS1-rearranged patients were correlated with the expressions of TTF1, napsin A and solid predominant adenocarcinoma subtype. Thirty-three ALK and six ROS1 rearrangement patients received crizotinib treatment at an advanced stage. The median PFS was 9.5 months for ALK-positive patients and it was not attained in ROS1-rearranged counterparts.

Conclusions

The frequency of ALK and ROS1 rearrangements is elevated in EGFR-wild-type patients and the phenomenon of coexisting ALK/ROS1 has remained extremely rare. The rearrangements of ALK/ROS1 are correlated with age, smoking status, expressions of TTF1 & napsin A and solid predominant adenocarcinoma subtype.

Unique distribution of programmed death ligand 1 (PD-L1) expression in East Asian non-small cell lung cancer

BACKGROUND

To determine the proportion and clinical features of programmed death ligand 1 (PD-L1) expression in East Asian non-small cell lung cancer (NSCLC).

METHODS

PD-L1 expression was assessed by immunohistochemistry (IHC) and tumor proportion score (TPS) with the use of PD-L1 IHC 22C3 antibody (Dako North America) in 108 surgically resected lung squamous cell carcinomas (SCC) and 221 lung adenocarcinomas (LUADs), and was correlated with clinical variables, histologic subtypes, and common driver mutations.

RESULTS

Positive PD-L1 expression was found in 37 lung SCC (37/108, 34.3%), including 15 cases with TPS ≥50% (15/108, 13.9%) and 22 cases with TPS <50% (22/108, 20.4%). In adenocarcinoma cohort, 9 cases were found PD-L1 expression positive (9/221, 4.1%), including 1 case with TPS ≥50% (1/221, 0.5%) and 8 cases with TPS <50% (8/221, 3.9%). Totally, high PD-L1 expression (TPS ≥50%) was significantly associated with male sex (P=0.026), current/ever smoking history (P=0.008) and SCC subtype (P<0.001). Positive PD-L1 expression (including TPS ≥50% and TPS <50%) in LUAD cohort was significantly associated with male sex (P=0.046), current/ever smoking history (P=0.002), mutation pan-negative status (P=0.038), solid-predominant subtype (P<0.001), large tumor size (P=0.027) and lymph node metastasis (P=0.019). No significant difference was found between PD-L1 high expression group (TPS ≥50%) and low/negative expression group in SCC cohort.

CONCLUSIONS

This study revealed the unique distribution of PD-L1 expression in East Asian NSCLCs, which is largely different from Western populations. Since the high response rate of pembrolizumab in the treatment of lung cancer patients with PD-L1 TPS ≥50%, this result indicates that prospective PD-L1 expression testing in specific East Asian patients could facilitate decision making for immunotherapy.

ALK and ROS1 concurrent with EGFR mutation in patients with lung adenocarcinoma

PURPOSE

The purpose of this study was to explore the frequencies of ALK and ROS1 fusion genes in EGFR-mutant lung adenocarcinoma patients and examine the therapeutic efficacies of EGFR-tyrosine kinase inhibitors (TKIs).

MATERIALS AND METHODS

A total of 421 EGFR-mutated patients taking EGFR-TKIs were examined for ALK and ROS1 fusion genes based on reverse transcription-polymerase chain reaction (RT-PCR). Progression-free survival (PFS) and overall survival (OS) were evaluated by the Kaplan-Meier method and compared by the log-rank test.

RESULTS

The mutations of ALK rearrangement (n=10) and ROS1 rearrangement (n=3) were detected. All the patients received EGFR-TKIs, and eight took subsequent ALK/ROS1 inhibitor. PFS was longer in single EGFR mutants (n=408) than in EGFR/ALK or EGFR/ROS1 counterparts (n=13; 10.7 vs 6.6 months, P=0.004). No difference in OS existed between single EGFR and EGFR/ALK or EGFR/ROS1 mutants (21.0 vs 23.0 months, P=0.196). The median PFS of eight patients treated with ALK/ROS1 inhibitor was 6.0 months.

CONCLUSION

Concomitant ALK/ROS1 fusion genes occurred in 3.1% EGFR-mutated lung adenocarcinoma patients. Concomitant ALK/ROS1-EGFR mutations may influence the therapeutic efficacy of EGFR-TKIs.

Comparison of Clinically Relevant Mutation Profiles Between Preoperative Biopsy and Corresponding Surgically Resected Specimens in Japanese Patients With Non-Small-cell Lung Cancer by Amplicon-based Massively Parallel Sequencing

BACKGROUND

Amplicon-based massively parallel sequencing (MPS) is an effective platform for identifying clinically actionable mutations across many genes in limited amounts of tissue. Most lung cancers are diagnosed and staged using small tissue samples obtained by transbronchial biopsy (TBB). To determine whether the mutations in TBB specimens detected by amplicon-based MPS reflect those present in the tumors, we compared the mutational profiles of preoperative TBB specimens and corresponding surgically resected specimens.

PATIENTS AND METHODS

Fresh-frozen primary tumor specimens from non-small-cell lung cancer patients (n = 46) obtained preoperatively by TBB and during surgical resection were analyzed. The concordance of mutations detected by amplicon-based MPS in the 2 sample types was investigated, and the allele frequency of the mutations common to both specimens from the same patient was determined.

RESULTS

An initial assessment of DNA quantity revealed that 46% of the TBB specimens (21 of 46) had less than the lower limit for amplicon-based MPS. These 21 TBB specimens were consequently omitted from the analysis. Of the 29 mutations detected in the TBB and/or surgically resected specimens from 25 patients, 23 were present in both samples, for a concordance rate of 79%.

CONCLUSION

Amplicon-based MPS with TBB specimens approximately reflects clinically relevant tumor mutation profiles. However, the rate of TBB specimens with sufficient DNA quantity for amplicon-based MPS was only around 50%. Therefore, surgically resected specimens have a valuable role in exploratory and comprehensive genomic profiling.

Clinicopathological characteristics and survival of ALK, ROS1 and RET rearrangements in non-adenocarcinoma non-small cell lung cancer patients

BACKGROUND

ALK, ROS1 and RET rearrangements represent 3 most frequent fusion genes in non-small cell lung cancer (NSCLC). Rearrangements of these 3 genes exist predominantly in lung adenocarcinoma while rarely in non-adenocarcinoma. Our objective was to explore the frequency, clinicopathological characteristics and survival of ALK, ROS1 and RET rearrangements in non-adenocarcinoma NSCLC patients.

METHODS

ALK, ROS1 and RET rearrangements were screened by reverse transcriptase polymerase chain reaction (RT-PCR) in patients with completely resected non-adenocarcinoma NSCLC. All positive samples were confirmed with fluorescence in situ hybridization (FISH). Survival analysis was performed with Kaplan-Meier method and log-rank for comparison.

RESULTS

A total of 385 patients underwent complete resection, including squamous cell carcinoma (n = 245), adenosquamous carcinoma (n = 85) and large cell carcinoma (n = 55). Twelve of them were identified as harboring fusion genes, including ALK (n = 7), ROS1 (n = 3) and RET (n = 2) rearrangements. The fusion frequencies of adenosquamous, squamous cell and large cell carcinomas were 8.2%, 1.6% and 1.8% respectively. Their median age was 49.5 y and 3 of them had a smoking history. No survival difference existed between fusion gene positive and negative patients (36.7 vs.50.2 months, P = 0.21).

CONCLUSION

The frequencies of ALK, ROS1 and RET rearrangements are low in non-adenocarcinoma NSCLC patients. And their clinical characteristics are similar to those in lung adenocarcinoma. Fusions of the above 3 genes are not prognostic factor for non-adnocarcinoma NSCLC patients.

Correlation of Histologic Subtypes and Molecular Alterations in Pulmonary Adenocarcinoma: Therapeutic and Prognostic Implications

Major driver mutations of pulmonary adenocarcinomas have been identified and highlighted as actionable targets for precision cancer medicine. As phenotype is largely determined by genotype, genetic changes associated with morphologic features have recently received more attention from both pathologists and clinicians. The morphologic features of adenocarcinomas with mutations in EGFR or KRAS, or translocated ALK, have rarely been described. Pulmonary adenocarcinomas with EGFR mutations, the most common driver mutation encountered in Asian patients with pulmonary adenocarcinoma, show lepidic or papillary organotypic growth patterns. KRAS-mutated adenocarcinomas demonstrate nonorganotypic growth patterns, especially mucin-containing cells. P53 mutations are associated with aggressiveness rather than growth patterns. HER2 mutations are observed in mucinous adenocarcinoma and adenocarcinoma with micropapillary features. The histologic features of BRAF-mutated adenocarcinomas have not yet been established, but papillary, lepidic, solid, and acinar patterns have been observed. Adenocarcinomas with rearrangement of ALK, ROS1, and RET genes share similar histologic features, such as solid signet-ring cells and cribriform formation. However, adenocarcinomas with NRG1 rearrangements frequently show mucinous morphology. The histologic features and related mutations of adenocarcinomas with expression of programmed cell death-1 and programmed cell death ligands-1 may be helpful in guiding immunotherapeutic treatment. This review describes histopathologic features of adenocarcinomas and their correlation with molecular alterations.

Epidermal growth factor receptor mutations in adenocarcinoma in situ and minimally invasive adenocarcinoma detected using mutation-specific monoclonal antibodies

OBJECTIVES

Epidermal growth factor receptor (EGFR) mutation rates in adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) were studied using both DNA analysis and mutation-specific immunohistochemistry.

MATERIALS AND METHODS

The peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method was used to detect mutations in exons 18, 19, 20, and 21 of the EGFR gene in DNA samples extracted from paraffin-embedded tissue sections. Simultaneously, immunohistochemical analysis with two EGFR mutation-specific monoclonal antibodies was used to identify proteins resulting from an in-frame deletion in exon 19 (E746_A750del) and a point mutation replacing leucine with arginine at codon 858 of exon 21 (L858R).

RESULTS

Forty-three tumors (22 AIS and 21 MIA) were examined. The EGFR mutation rate in AIS detected by DNA analysis was 27.3% (L858R, 5/22; exon 19 deletion,1/22), whereas that detected in MIA was 42.9% (L858R,4/21; exon 19 deletion,5/21). Mutations detected by immunohistochemical analysis included 22.7% (L858R, 4/22; exon 19 deletion, 1/22) in AIS and 42.9% (L858R, 4/21; exon 19 deletion, 5/21) in MIA. Although some results were contradictory, concordant results were obtained using both assays in 38 of 43 cases (88.4%).

CONCLUSION

DNA and immunohistochemical analyses revealed similar EGFR mutation rates in both MIA and AIS, suggesting that mutation-specific monoclonal antibodies are useful to confirm DNA assay results.

Clinical efficacy of first-generation EGFR-TKIs in patients with advanced non-small-cell lung cancer harboring EGFR exon 20 mutations

PURPOSE

Subsets of non-small-cell lung cancer patients with epidermal growth factor receptor (EGFR) mutations carry uncommon subtypes. We evaluated the efficacy of first-generation EGFR-tyrosine kinase inhibitors (TKIs; erlotinib, gefitinib, and icotinib) in patients with non-small-cell lung cancer carrying insertions and T790M and S768I mutations in EGFR exon 20.

PATIENTS AND METHODS

Patients carrying EGFR exon 20 insertion/T790M/S768I mutations and treated with EGFR-TKIs were evaluated from 2005 to 2014 in Zhejiang Cancer Hospital. The efficacy was evaluated using the Kaplan-Meier method and compared with the log-rank test.

RESULTS

Sixty-two patients with exon 20 insertion/T790M/S768I mutations were enrolled. Mutations including exon 20 insertions and T790M and S768I mutations were observed in 29, 23, and ten patients, respectively. In total, the response rate and median progression-free survival (PFS) were 8.1% and 2.1 months, respectively. Patients with S768I mutation manifested the longest median PFS (2.7 months), followed by those with T790M (2.4 months) and exon 20 insertions (1.9 months; P=0.022). Patients with complex mutations show a better PFS than those with single mutations (2.7 months vs 1.9 months; P=0.034).

CONCLUSION

First-generation EGFR-TKIs are less effective in patients with exon 20 uncommon mutations than in those with common mutations. Patients with complex mutations benefited more from first-generation EGFR-TKIs than those with single mutations.

MET exon 14 skipping defines a unique molecular class of non-small cell lung cancer

PURPOSE

Recurrent MET exon 14 splicing has been revealed in lung cancers and is a promising therapeutic target. Because we have limited knowledge about the natural history of MET mutant tumors, the current study was aiming to determine the clinical and pathological characteristics in non-small cell lung cancers (NSCLC).

RESULTS

Twenty-three patients (1.3%) were positive for MET exon 14 skipping. Patients with MET exon 14 skipping displayed unique characteristics: female, non-smokers, earlier pathology stage and older age. MET exon 14 skipping indicated an early event as other drivers in lung cancer, while MET copy number gain was more likely a late event in lung cancer. Overall survival (OS) of patients harboring MET exon 14 skipping was longer than patients with KRAS mutation. Almost four-fifths of the lung tumors with MET exon 14 skipping had EGFR and/or HER2 gene copy number gains. EGFR inhibitor showed moderate antitumor activity in treatment of a patient harboring MET exon 14 skipping.

PATIENTS AND METHODS

From October 2007 to June 2013, we screened 1770 patients with NSCLC and correlated MET status with clinical pathologic characteristics and mutations in EGFR, KRAS, BRAF, HER2, and ALK. Quantitative Real-Time PCR was used to detect MET gene copy number gain. Immunohistochemistry (IHC) was also performed to screen MET exon 14 skipping. Clinicopathological characteristics and survival information were analyzed.

CONCLUSIONS

MET exon 14 skipping was detected in 1.3% (23/1770) of the Chinese patients with NSCLC. MET exon 14 skipping defined a new molecular subset of NSCLC with identifiable clinical characteristics. The therapeutic EGFR inhibitors might be an alternative treatment for patients with MET mutant NSCLC.

Clinical significance of serum and urinary HER2/neu protein levels in primary non-muscle invasive bladder cancer

Objective:

We aimed to compare serum and urinary HER2/neu levels between healthy control group and patients with non-muscle invasive bladder cancer. Additionally, we evaluated relationship of HER2/neu levels with tumor stage, grade, recurrence and progression.

Materials and Methods:

Fourty-four patients with primary non-muscle invasive bladder tumors (Group 2) and 40 healthy control group (Group 1) were included the study. Blood and urinary samples were collected from all patients and HER2/neu levels were measured by ELISA method. Blood and urinary HER2/neu levels and additionally, ratio of urinary HER2/neu levels to urinary creatinine levels were recorded. Demographic data and tumor characteristics were recorded.

Results:

Mean serum HER2/neu levels were similar between two groups and statistically significant difference wasn't observed. Urinary HER2/neu levels were significantly higher in group 2 than group 1. Ratio of urinary HER2/neu to urinary creatinine was significantly higher in group 2 than group 1, (p=0,021). Serum and urinary HER2/ neu levels were not associated with tumor stage, grade, recurrence and progression while ratio of urinary HER2/neu to urinary creatinin levels were significantly higher in high-grade tumors. HER2/neu, the sensitivity of the test was found to be 20.5%, and the specificity was 97.5%, also for the urinary HER2/neu/urinary creatinine ratio, the sensitivity and specificity of the test were found to be 31.8% and 87.5%, respectively.

Conclusions:

Urinary HER2/neu and ratio of urinary creatinine urine were significantly higher in patients with bladder cancer compared to healthy subjects. Large series and controlled studies are needed for use as a tumor marker.