High Discrepancy of Driver Mutations in Patients with NSCLC and Synchronous Multiple Lung Ground-Glass Nodules

Comprehensive Next-Generation Sequencing Unambiguously Distinguishes Separate Primary Lung Carcinomas From Intrapulmonary Metastases: Comparison with Standard Histopathologic Approach

PURPOSE

In patients with >1 non-small cell lung carcinoma (NSCLC), the distinction between separate primary lung carcinomas (SPLCs) and intrapulmonary metastases (IPMs) is a common diagnostic dilemma with critical staging implications. Here, we compared the performance of comprehensive next-generation sequencing (NGS) with standard histopathologic approaches for distinguishing NSCLC clonal relationships in clinical practice.

EXPERIMENTAL DESIGN

We queried 4,119 NSCLCs analyzed by 341-468 gene MSK-IMPACT NGS assay for patients with >1 surgically resected tumor profiled by NGS. Tumor relatedness predicted by prospective histopathologic assessment was contrasted with comparative genomic profiling by subsequent NGS.

RESULTS

Sixty patients with NGS performed on >1 NSCLCs were identified, yielding 76 tumor pairs. NGS classified tumor pairs into 51 definite SPLCs (median, 14; up to 72 unique somatic mutations per pair), and 25 IPMs (24 definite, one high probability; median, 5; up to 16 shared somatic mutations per pair). Prospective histologic prediction was discordant with NGS in 17 cases (22%), particularly in the prediction of IPMs (44% discordant). Retrospective review highlighted several histologic challenges, including morphologic progression in some IPMs. We subsampled MSK-IMPACT data to model the performance of less comprehensive assays, and identified several clinicopathologic differences between NGS-defined tumor pairs, including increased risk of subsequent recurrence for IPMs.

CONCLUSIONS

Comprehensive NGS allows unambiguous delineation of clonal relationship among NSCLCs. In comparison, standard histopathologic approach is adequate in most cases, but has notable limitations in the recognition of IPMs. Our results support the adoption of broad panel NGS to supplement histology for robust discrimination of NSCLC clonal relationships in clinical practice.

Clonality analysis of pulmonary tumors by genome-wide copy number profiling

Multiple tumors in patients are frequently diagnosed, either synchronous or metachronous. The distinction between a second primary and a metastasis is important for treatment. Chromosomal DNA copy number aberrations (CNA) patterns are highly unique to specific tumors. The aim of this study was to assess genome-wide CNA-patterns as method to identify clonally related tumors in a prospective cohort of patients with synchronous or metachronous tumors, with at least one intrapulmonary tumor. In total, 139 tumor pairs from 90 patients were examined: 35 synchronous and 104 metachronous pairs. Results of CNA were compared to histological type, clinicopathological methods (Martini-Melamed-classification (MM) and ACCP-2013-criteria), and, if available, EGFR- and KRAS-mutation analysis. CNA-results were clonal in 74 pairs (53%), non-clonal in 33 pairs (24%), and inconclusive in 32 pairs (23%). Histological similarity was found in 130 pairs (94%). Concordance between histology and conclusive CNA-results was 69% (74 of 107 pairs: 72 clonal and two non-clonal). In 31 of 103 pairs with similar histology, genetics revealed non-clonality. In two out of four pairs with non-matching histology, genetics revealed clonality. The subgroups of synchronous and metachronous pairs showed similar outcome for the comparison of histological versus CNA-results. MM-classification and ACCP-2013-criteria, applicable on 34 pairs, and CNA-results were concordant in 50% and 62% respectively. Concordance between mutation matching and conclusive CNA-results was 89% (8 of 9 pairs: six clonal and two non-clonal). Interestingly, in one patient both tumors had the same KRAS mutation, but the CNA result was non-clonal. In conclusion, although some concordance between histological comparison and CNA profiling is present, arguments exist to prefer extensive molecular testing to determine whether a second tumor is a metastasis or a second primary.

Attenuation and Morphologic Characteristics Distinguishing a Ground-Glass Nodule Measuring 5-10 mm in Diameter as Invasive Lung Adenocarcinoma on Thin-Slice CT

OBJECTIVE. The purpose of this study is to comprehensively investigate the role of multiple features seen on thin-section CT (TSCT) in the differential diagnosis of ground-glass nodules (GGNs) measuring 5-10 mm in diameter as invasive adenocarcinoma (IAC). MATERIALS AND METHODS. The TSCT features of 313 surgically diagnosed GGNs from 288 patients were retrospectively reviewed. A logistic regression model was applied, and the AUC values for the model and the size and attenuation of the lesions were compared using ROC curve analysis. RESULTS. A total of 247 lung adenocarcinomas in situ (AISs) and minimally invasive adenocarcinomas (MIAs) (hereafter referred to as the AIS-MIA group) and 66 invasive adenocarcinomas (IACs) were identified. Compared with the AIS-MIA group, the IAC groups were significantly larger in size and had higher attenuation values, a higher frequency of mixed GGNs (all p < 0.001), bubblelike appearance, spiculation, pleural indentation, different locations, and a lower frequency of clear tumor-lung interface (all p < 0.05). The logistic model included size and attenuation (both p < 0.001; odds ratio [OR], 1.872 and 1.009, respectively) as well as tumor-lung interface (p = 0.001; OR, 0.242), bubblelike appearance (p < 0.05; OR, 2.205), and type of nodule. The AUC value for the logistic model was 0.847 (sensitivity, 80.3%; specificity, 81.0%) and was significantly higher than that for size or attenuation (both p < 0.01). CONCLUSION. Radiologic features could help in the differential diagnosis of a GGN that was 5-10 mm in diameter as IAC versus AIS or MIA. GGNs larger than 8.12 mm and with attenuation greater than -449.52 HU were more likely to be IAC.

Molecular heterogeneity in lung cancer: from mechanisms of origin to clinical implications

Molecular heterogeneity is a frequent event in cancer responsible of several critical issues in diagnosis and treatment of oncologic patients. Lung tumours are characterized by high degree of molecular heterogeneity associated to different mechanisms of origin including genetic, epigenetic and non-genetic source. In this review, we provide an overview of recognized mechanisms underlying molecular heterogeneity in lung cancer, including epigenetic mechanisms, mutant allele specific imbalance, genomic instability, chromosomal aberrations, tumor mutational burden, somatic mutations. We focus on the role of spatial and temporal molecular heterogeneity involved in therapeutic implications in lung cancer patients.

Concomitant EGFR Mutation and EML4-ALK Rearrangement in Lung Adenocarcinoma Is More Frequent in Multifocal Lesions

BACKGROUND

The coexistence of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement in patients with multifocal lung adenocarcinomas (LUAC) constitutes a rare molecular subtype of lung cancer. We aimed to investigate the intertumoral heterogeneity of pathologic and genetic characteristics of multifocal LUAC with EGFR/ALK co-alterations.

PATIENTS AND METHODS

A total of 1059 LUAC patients who underwent resection were investigated to screen for EGFR or ALK alterations using amplification refractory mutation system polymerase chain reaction and immunohistochemistry/fluorescence in situ hybridization. Molecular testing was extensively performed in patients with synchronous multifocal LUAC. Clonal evolution analysis was implemented using next-generation sequencing.

RESULTS

A total of 97 multiple synchronous lesions were observed among 1059 LUAC patients. Patients with at least 1 sample harboring EGFR mutation or ALK rearrangement were 62.89% (61/97) and 14.43% (14/97), respectively. Patients with concomitant EGFR and ALK alterations were 4.71% (4/97). Comparatively, patients with unifocal LUAC harboring EGFR mutation, ALK rearrangement, and EGFR/ALK co-alterations were 58.25% (570/962), 6.44% (62/962), and 0.83% (8/962), respectively. The prevalence of EGFR/ALK co-alterations in the multifocal LUAC was significantly higher than that in the unifocal LUAC (4.71% (4/97) vs. 0.83% (8/962)). Furthermore, we present 4 cases of EGFR/ALK co-altered multifocal LUAC with different morphological and molecular patterns. In addition to radiographic, pathological, and molecular testing results, clonal evolutional analysis could also be used to distinguish intertumoral heterogeneity.

CONCLUSION

The results highlight the importance of distinguishing synchronous primary tumors from intrapulmonary metastases, and of assessing the relative abundance of EGFR mutation and ALK rearrangement in patients with multifocal adenocarcinomas with EGFR/ALK co-alterations.

Germline Predisposition and Copy Number Alteration in Pre-stage Lung Adenocarcinomas Presenting as Ground-Glass Nodules

Objective: Synchronous multiple ground-glass nodules (SM-GGNs) are a distinct entity of lung cancer which has been emerging increasingly in recent years in China. The oncogenesis molecular mechanisms of SM-GGNs remain elusive. Methods: We investigated single nucleotide variations (SNV), insertions and deletions (INDEL), somatic copy number variations (CNV), and germline mutations of 69 SM-GGN samples collected from 31 patients, using target sequencing (TRS) and whole exome sequencing (WES). Results: In the entire cohort, many known driver mutations were found, including EGFR (21.7%), BRAF (14.5%), and KRAS (6%). However, only one out of the 31 patients had the same somatic missense or truncated events within SM-GGNs, indicating the independent origins for almost all of these SM-GGNs. Many germline mutations with a low frequency in the Chinese population, and genes harboring both germline and somatic variations, were discovered in these pre-stage GGNs. These GGNs also bore large segments of copy number gains and/or losses. The CNV segment number tended to be positively correlated with the germline mutations (r = 0.57). The CNV sizes were correlated with the somatic mutations (r = 0.55). A moderate correlation (r = 0.54) was also shown between the somatic and germline mutations. Conclusion: Our data suggests that the precancerous unstable CNVs with potentially predisposing genetic backgrounds may foster the onset of driver mutations and the development of independent SM-GGNs during the local stimulation of mutagens.

Genomic alterations and survival in young patients aged under 40 years with completely resected non-small cell lung cancer

Background

Young patients are rarely diagnosed with non-small cell lung cancer (NSCLC), and little is known about its predisposing genomic alterations and survival.

Methods

This retrospective study was conducted to evaluate the genomic alterations, treatment and prognosis of young patients under 40 years old from a cohort of 640 lung adenocarcinoma and squamous carcinoma cases from Zhejiang Cancer Hospital. All patients were examined for EGFR, KRAS, NRAS, PIK3CA, BRAF and HER2 mutations and ALK, ROS1 and RET fusion genes.

Results

In total, 54 patients were aged under 40 years. The frequencies of genomic alterations in younger (≤40 years) and older (>40 years) patients were 68.5% and 54.8%, respectively (P=0.05). Younger patients harbored a higher frequency of fusion genes (22.2% vs. 4.1%, P<0.001) but not gene mutations (46.3% vs. 45.6%, P=0.92). There was a general trend toward shorter recurrence-free survival (RFS) (35.2 vs. 43.8 months, P=0.050), while no overall survival (OS) difference existed between younger and older patients (50.2 vs. 51.4 months, P=0.112).

Conclusions

Younger patients with NSCLC had a higher frequency of gene fusions than older patients and had a trend of worse OS.

Multiple primary lung cancer: a rising challenge

With the use of high-resolution chest imaging system and lung cancer screening program, patients with multiple primary lung cancers (MPLCs) are becoming a growing population in clinical practice worldwide. The diagnostic criteria for MPLCs has been established and modified by three major lung cancer research institutes. However, due to the fact that the differential diagnosis between MPLCs and a recurrence, metastatic, or satellite lesion arising from the original lesion remains ambiguous and confusing, there is still insufficient evidence to support a uniform guideline. Newly developed molecular and genomic methods have the potential to better define the relationship among multiple lesions and bring the possibility of targeted therapy. Surgical resection remains the first choice for the treatment of MPLCs and detailed strategy should be carefully planned taking characteristics of the tumor and status of patients into consideration. For those who are intolerant to surgery, a new technology called stereotactic body radiation therapy (SBRT) is now an optional therapeutic strategy. Furthermore, multiple GGOs are unique MPLCs that need special attentions in the clinical practice.

Epidermal Growth Factor Receptor (EGFR) Mutations and Anaplastic Lymphoma Kinase/Oncogene or C-Ros Oncogene 1 (ALK/ROS1) Fusions Inflict Non-Small Cell Lung Cancer (NSCLC) Female Patients Older Than 60 Years of Age

Background

Lung cancer has become a leading disease for the tumor-induced mortality. Non-small cell lung cancer (NSCLC) accounts for approximately 80% of all lung cancers. The present research aimed to evaluate the correlation between the anaplastic lymphoma kinase/oncogene or c-ros oncogene 1 (ALK/ROS1) fusions or mutations of epidermal growth factor receptor (EGFR) and ages or gender of patients.

Material/Methods

Among 1449 NSCLC patients, 457 patients who were diagnosed as consecutive EGFR mutations or ALK/ROS1 fusions between November 2016 and February 2018 were involved in the present study. EGFR genes or ALK/ROS1 mutations were detected by using DNA sequencing technique and amplification-refractory mutation system (ARMS). The mRNAs of ROS1 and ALK fusion were examined by using polymerase chain reaction technique and fusion gene detection kit.

Results

Females were more often inflicted by the EGFR mutations, especially for the exon 19 deletion and L858R mutation. There were significantly more ALK/ROS1 fusions in females compared to males (P<0.05) and significantly more ALK/ROS1 fusions in <60 years of age patients compared to patients older than 60 years of age (P<0.05). Exon 21 L858R and L861Q dominantly occurred in patients ≥60 years of age and exon 19 deletion in patients <60 years of age. EML-ALK-1 mainly existed in the female NSCLC patients.

Conclusions

EGFR mutations and ALK/ROS1 fusions mainly occurred in the NSCLC female patients who were older than 60 years of age.

Expression of p53 in ground-glass nodule of lung cancer and non-lung cancer patients

The present study investigated the expression of p53 in ground-glass nodule (GGN) of lung cancer and non-lung cancer patients, and explored the correlation with prognosis. A total of 120 GGN patients admitted to the Department of Respiratory Medicine in the Second Affiliated Hospital of Zhejiang University School of Medicine during the period from March 2010 to March 2014 were selected. These patients included 60 lung cancer patients and 60 non-tumor patients. Biopsy or surgical specimens were collected. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were used to detect p53 gene and protein expression in the two groups of GGN tissues. All patients were followed up for 3 years and the relationship between p53 protein expression and the overall survival (OS) of the two groups of patients was analyzed. In GGN cells of non-cancer patients, p53 absence was observed in 6 cases and the absence rate was 10.0%. In GGN cells of cancer patients, the absence rate was significantly higher than that of non-cancer GGN group (p<0.05). The positive rate of p53-positive cases in non-tumor patients GGN group was lower than that of in GGN tissues of lung cancer patients (p<0.05). There were no deaths in the GGN non-cancer group (n=60) within 3 years, while 43 deaths occurred in GGN lung cancer group. The median survival time and the 3-year survival rate of patients with p53 positive was lower than that of p53-negative patients (p<0.05). p53 was overexpressed in GGN of lung cancer patients, and p53 overexpression is significantly correlated with poor prognosis of lung cancer patients. p53 plays an important role in transformation from GGN to lung cancer. Detection of p53 expression in GGN tissue may provide guidance for the diagnosis and prognosis of lung cancer.

Comparative mutational evaluation of multiple lung cancers by multiplex oncogene mutation analysis

In patients presenting with synchronous or metachronous multiple lung cancer (MLC), it is important to distinguish between multiple primary lung cancer (MP) and intrapulmonary metastasis (IM). The present study was aimed at investigating the mutational profiles of synchronous/metachronous MLC and to compare the classification of paired tumors by multiplex gene mutation analysis with the histopathological evaluation. We carried out targeted sequencing of 20 lung cancer-related oncogenes using next-generation sequencing (NGS) in 82 tumors from 37 MLC patients who underwent surgical resection at our department. The patients were diagnosed as MP or IM cases based on the Martini and Melamed criteria, histopathological and gene mutational evaluations. Matching mutations between paired tumors was observed in 20 (54%) patients, who were diagnosed as IM cases by mutational evaluation. Patients who could not be clearly diagnosed by histopathological evaluation were classified as equivocal cases. Among the histopathological IM cases (n = 7), six (86%) were confirmed as IM cases also by mutational evaluation, and most of the paired tumors of these cases (n = 5) harbored multiple matching mutations. Among the histopathological MP cases (n = 17), mutational evaluation yielded a discordant diagnosis in eight (47%) cases. Of these, the paired tumors of four cases harbored multiple matching mutations, suggesting that the mutational diagnosis might be more suitable in these patients. Our findings suggest that multiplex mutational analysis could be a useful complementary tool for distinguishing between MP and IM in addition to histopathological evaluation.

Applicability of the lung-molGPA index in non-small cell lung cancer patients with different gene alterations and brain metastases

OBJECTIVES

The Lung-molGPA index is based on the original diagnosis-specific graded prognostic assessment (DS-GPA) and incorporates recently reported gene alteration data, predicting the outcomes of non-small cell lung cancer (NSCLC) patients with brain metastases (BM). However, the prognostic values of both DS-GPA and Lung-molGPA remain undetermined, especially for patients with different molecular types.

MATERIALS AND METHODS

A total of 1184 NSCLC patients with BM were analyzed for clinical factors and outcomes at Zhejiang Cancer Hospital, China. All prognostic factors were weighted for significance by hazard ratios. The applicability of DS-GPA and Lung-molGPA were reappraised in NSCLC patients with BM and various genetic profiles. Additionally, a modified Lung-molGPA was newly developed for NSCLC patients with gene variations.

RESULTS

NSCLC patients in the present study had a median survival time of 14.0 months from BM diagnosis. Both the DS-GPA and Lung-molGPA models could effectively predict the outcomes of NSCLC patients with BM (P < 0.001), and the Lung-molGPA model appeared to deliver more accurate predictions. Furthermore, Lung-molGPA scores demonstrated discriminatory capability in patients with gene variations (P < 0.001), and no significant difference was reached in wild-type patients (P = 0.133). Regarding oncogene-positive NSCLC patients with BM, a modified Lung-molGPA index was established based on the prognostic factors with a C-index of 0.73 (95% CI: 0.68-0.80) to accurately calculate survival probability (P < 0.001).

CONCLUSIONS

In the era of precision medicine, Lung-molGPA accurately predicted the prognosis of NSCLC patients with mutant genotypes and BM, although it did not perform well in wild-type patients. Thus, it is worthwhile to explore the prognostic model for patients with positive driving genes.

Ground-glass nodules of the lung in never-smokers and smokers: clinical and genetic insights

Pulmonary ground-glass nodules (GGNs) are hazy radiological findings on computed tomography (CT). GGNs are detected more often in never-smokers. Retrospective and prospective studies have revealed that approximately 20% of pure GGNs and 40% of part-solid GGNs gradually grow or increase their solid components, whereas others remain stable for years. Most persistent or growing GGNs are lung adenocarcinomas or their preinvasive lesions. To distinguish GGNs with growth from those without growth, GGNs should be followed for at least 5 years. Lesion size and smoking history are predictors of GGN growth. Genetic analyses of resected GGNs have suggested that EGFR mutations are also predictors for growth but a subset of KRAS- or BRAF-mutated GGNs may undergo spontaneous regression because the frequencies of KRAS or BRAF mutations decrease with the advance of pathological invasiveness. Although lobectomy is the standard surgical procedure for lung cancer, limited surgery such as wedge resection or segmentectomy for lung cancers ≤2 cm with consolidation/tumor ratio ≤0.25 can be a viable alternative based on the recent clinical trial. Further genetic analyses and clinical trials can contribute to elucidation of the biological aspects of preinvasive adenocarcinoma and the development of less invasive management strategies for patients with GGNs.

Clonality assessment of multifocal lung adenocarcinoma by pathology evaluation and molecular analysis

The aim of this study was to explore morphologic and molecular features distinguishing between multifocal lung adenocarcinoma (MLA) and intrapulmonary metastases (IMs). Sixteen patients with MLAs, a total of 34 tumors, were reviewed. Four approaches were used: (1) array-comparative genomic hybridization (CGH) as a standard clonality assessment; (2) EGFR and KRAS mutational profiles as a supplementary method; (3) comprehensive histologic assessment (CHA) was method I in pathology evaluation; and (4) CHA combined with lepidic component analysis was method II. The lepidic component was divided into low grade and high grade according to extent of atypia; tumors with low-grade lepidic component were defined as primary. Eight patients were found to have IMs and 8 to have multiple primaries (MPs) by array-CGH; 7 had MPs and 9 had IMs by method I; 5 had MPs and 11 had IMs by method II. Compared with array-CGH, method I had a lower coincidence rate (65%) than method II (85%). Univariate analysis revealed that patients with MP had a better clinical outcome than those with IM only if the MPs were diagnosed by array-CGH (P = .034) or method II (P = .027) but not EGFR/KRAS mutation (P = .843) or method I (P = .493). Our results suggest that a low-grade lepidic component is a sign of a primary tumor. CHA combined with a low-grade lepidic component (method II) is more accurate clinically and more cost-effective in distinguishing MLAs from IMs. Also, EGFR mutation is not an appropriate molecular marker for clonality assessment.

A case of different EGFR mutations in surgically resected synchronous triple lung cancer

We describe a 77-year-old Japanese woman who presented with three nodule shadows in three different lobes of the right lung, without evidence of lymph node metastasis or distant metastasis. All three tumors were surgically resected. The pathological diagnosis was synchronous multiple primary lung cancer: pT2aN0M0, pStageIB. Based on a differing epidermal growth factor receptor (EGFR) mutation status, no lymph node metastasis, and no distant metastasis, the tumors were characterized as synchronous triple primary rather than intrapulmonary metastases. At eight months after surgery, a new lesion emerged in the right lower lobe. Given that the most advanced tumor had an EGFR del-19 mutation, the patient was orally administered afatinib. Since then, the treatment response of the patient has been assessed as stable disease (SD) for about two years. This is a very rare case of resected triple synchronous primary lung cancer on the same lung side in which the lesions all had a different EGFR mutation status, and this report highlights the clinical utility of surgical resection of multifocal lung nodules without lymph node metastasis or distant metastasis in order to optimize therapy for patients with known driver mutations.

[The Clinical and Molecular Characteristics of Adenocarcinoma Presented by Multi-focal GGO]

随着人们对肺癌早期筛查的重视，肺多发磨玻璃影（multiple ground glass opacities, GGOs）的检出率逐年增高，以GGOs为表现的多灶肺腺癌也逐渐成为临床研究热点。其更多见于女性、非吸烟者，且无论是自然病程还是手术后的患者均有极佳预后。独特的临床特征提示其很可能是相对独立的一种疾病形式。从分子遗传学路径对其的探究发现，同一个体内的多个病灶间极可能有截然不同的克隆性特征，因此遗传异质性（genetic heterogeneity）是以GGOs为表现多灶肺腺癌最显著的分子遗传学特征。此特征可辅助原发多灶肺腺癌与肺癌肺内转移的鉴别诊断，也提示了对病灶进行分子遗传学检测的治疗意义。部分呈现出遗传相似性的GGOs病灶为气腔播散转移（spread through air spaces, STAS）理论提供了新的证据。

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.

Distinct clinicopathologic features, genomic characteristics and survival of central and peripheral pulmonary large cell neuroendocrine carcinoma: From different origin cells?

BACKGROUND

Pulmonary large cell neuroendocrine carcinoma (LCNEC) represents a rare entity in lung cancer with dismal prognosis. In the present study, we investigated whether there are significant differences between central and peripheral tumors of LCNEC, in terms of clinicopathologic features, genomic profiles, and survival.

METHODS AND MATERIALS

A total of 126 cases of LCNEC were included. The tumors with invasion of the segmental and/or lobar bronchus were classified as central LCNEC and those without as peripheral LCNEC. EGFR/BRAF/Kras mutations and ALK/ROS1 translocations were detected. Overall survival (OS) was evaluated by the Kaplan-Meier plots.

RESULTS

The majority of LCNEC proved to be of the peripheral type (64.3%, 81/126). Central tumors were associated with smoking habit (p = 0.047), higher TNM-stage (p = 0.014) and larger tumor size (p < 0.001). Expression of neuroendocrine markers (CD56, CGA, and SYN) was not significantly different by tumor location but central tumors had higher serum levels of NSE (p = 0.004). Peripheral tumors had a higher incidence of EGFR mutations (18.8% vs. 0%, p = 0.023). ROS1 translocation was detected in 1 patient with peripheral LCNEC. RB1 protein was more frequently expressed in peripheral tumor than central tumor. The median OS was 3.71 years in the entire cohort. Peripheral tumors had better survival compared with central tumors (median OS: 4.04 vs. 1.51 years, p < 0.001). Multivariate analyses demonstrated tumor location (hazard ratio [HR], 6.07, 95% confidence interval [CI], 1.57-23.44, p = 0.009), resection status (HR, 6.58, 95% CI, 1.92-22.51, p = 0.003) and EGFR mutational status (HR, 0.18, 95% CI, 0.04-0.75, p = 0.018) were independent prognostic factors for OS.

CONCLUSION

Primary tumor location of LCNEC, divided into central and peripheral type, has distinct clinicopathologic features, genomic characteristics and survival. These differences are likely due to differences in the origin cells and pathogenesis of these tumors.

EGFR, KRAS, BRAF and HER2 testing in metastatic lung adenocarcinoma: Value of testing on samples with poor specimen adequacy and analysis of discrepancies

Molecular testing on metastatic lung adenocarcinoma or on non-small cell non-squamous lung carcinoma often relies on small specimen. In this group of patient with poor specimen adequacy, we analyzed the rate of EGFR, KRAS, BRAF and HER2 mutations compared to their rate in optimal specimen. We analyzed discrepancies in molecular testing results in patients with iterative analysis on several samples. We performed a retrospective study of 1538 samples consecutively analyzed. 263/665 (39,5%) biopsies and 37/708 (5,2%) surgical specimens were considered as samples with poor specimen adequacy (p<0,0001). A lower tumor cell content was associated with a lower rate of KRAS mutation: 15,8% in samples with <10% of tumor cells or <100 tumor cells versus 29,8% in samples with >10% tumor cell and >100 tumor cells (p=0,001). KRAS mutational rate was at 11,1% in cytology specimens, significantly lower than in biopsy or surgical specimens respectively at 28,2% and 28,5% (p=0,0002). Tumor cell content was not associated with mutational rate for EGFR, BRAF and HER2 mutations. DNA quantity was not associated with mutational rate for EGFR, KRAS, BRAF and HER2. A discrepancy in molecular testing was found in 16 patients. For 5 patients there was also a discrepancy for TTF-1 expression. On the 11 without TTF-1 discrepancy, specimen adequacy was not fulfilled in 10 cases at least for tumor content. Discrepancies were found in the case of low cellularity, poor cell content or testing on cytological specimens. Tumor cell content is a crucial parameter for molecular analysis rather than the type of specimen or the DNA quantity. Discrepancies in molecular testing results are rare but might suggest the presence of another tumor type, the emergence of another clone or a molecular testing in a sample with low cell content.

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.

Histopathologic and molecular approach to staging of multiple lung nodules

Distinguishing multiple primary lung cancers from intrapulmonary metastases in patients with synchronous multifocal lung adenocarcinomas can be challenging. The most recent 8th edition American Joint Committee on Cancer staging manual (AJCC staging manual) distinguishes four disease patterns in patients with multiple lung nodules: (I) two or more distinct and histologically different masses (considered unrelated and staged as individual cancers); (II) multiple ground-glass or part-solid nodules, histologically of with lepidic growth pattern (considered separate tumors, T staged based on highest T stage lesion); (III) patchy areas of ground-glass and consolidations, histologically often invasive mucinous adenocarcinomas (considered single tumor with diffuse "pneumonic-type" involvement); and (IV) separate nodules with the same histologic features based on comprehensive histologic subtyping (considered intrapulmonary metastases). Histologic and molecular features, in conjunction with clinical and radiological information, can all be tools to assist with staging of multiple nodules. Histologic features of adenocarcinomas are best characterized using comprehensive histologic subtyping (percentage of lepidic, acinar, solid, papillary and micropapillary pattern). Genomic alterations are commonly assessed using fluorescence in-situ hybridization and next generation sequencing (NGS). The AJCC considers exactly matching breakpoints by comparative genomic hybridization (CGH) as the only evidence for intrapulmonary metastases, and clearly different histologic types or subtypes as the only evidence for separate primary tumors. Similar histologic subtypes or the same biomarker pattern are considered merely relative arguments in favor of a single tumor source. When assessing multifocal lung cancer, pathologists should consider, and carefully weigh the importance of, molecular testing results in addition to the tumor's histologic features. For many cases encountered in routine clinical practice, absolute certainty cannot be reached as to whether they represent multiple primary cancers or intrapulmonary metastases. Classification of difficult cases often benefits from multidisciplinary discussion.

Characterization of distinct types of KRAS mutation and its impact on first-line platinum-based chemotherapy in Chinese patients with advanced non-small cell lung cancer

We performed this retrospective study to investigate whether the KRAS mutation status and its subtypes could predict the effect of first-line platinum-based chemotherapy in Chinese patients with non-small cell lung cancer (NSCLC). Patients received who had KRAS mutations were enrolled. Correlations between KRAS mutations, specific mutant subtypes and responses to chemotherapy were analyzed using Kaplan-Meier and Cox proportional hazard methods. A total of 2,183 cases who received KRAS mutation detection were included. A total of 218 of these cases were indicated to have KRAS mutations. KRAS mutations were identified more commonly in males compared with females (P=0.035). The most common subtypes were G12C, G12D and G12V. Among 73 KRAS mutant patients and 100 EGFR/ALK/KRAS wild-type patients with advanced NSCLC, KRAS-mutant NSCLC patients had a significantly shorter progression-free survival (P=0.007) compared with NSCLC patients with KRAS wild-type. In addition, there was a shorter but marginally statistically significant progression-free survival (PFS) in KRAS mutant patients with adenocarcinoma compared with those with non-adenocarcinoma (P=0.051). In the KRAS mutant group, patients with the KRAS G12V mutation had the poorest PFS compared with non-G12V mutant cases (P=0.045). In conclusion, KRAS mutation was a negative predictive factor of PFS in Chinese patients with advanced NSCLC who received first platinum-based chemotherapy. Patients with KRAS G12V mutations exhibited the poorest PFS compared with those with other KRAS mutant types.

Continuation of gefitinib plus chemotherapy prolongs progression-free survival in advanced non-small cell lung cancer patients who get acquired resistance to gefitinib without T790M mutations

Background

Aimed to identify the benefit population from continuation of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), this study investigated the efficacy of continuation of EGFR-TKIs plus chemotherapy beyond the response evaluation criteria in solid tumors-progressive disease (RECIST-PD) according to different progression modes and T790M mutational status.

Methods

From November 2009 to July 2015, 630 patients with advanced non-small cell lung cancer (NSCLC) receiving gefitinib as initial EGFR-TKI treatment were screened in Shanghai Pulmonary Hospital. A total of 170 patients with documented gradual or dramatic progression after gefitinib treatment who received chemotherapy alone or in combination with gefitinib were included. Post-RECIST-PD progression-free survival (PPFS) between continuation of gefitinib plus chemotherapy and chemotherapy alone was assessed.

Results

The incidence of T790M mutation was 42.9% (63/147) in patients who got acquired resistance in this study. Median PPFS was 4.0 months [95% confidence interval (CI), 3.1-4.9 months] in the chemotherapy group and 5.0 months (95% CI, 3.6-6.4 months) in the combination group with a borderline statistical significance (P=0.071). Continuation of gefitinib plus chemotherapy resulted in a significant improvement in PPFS compared with chemotherapy alone in patients with EGFR^T790M-negative tumors [median PPFS: 6.6 vs. 3.5 months, hazard ratio (HR) 0.50, 95% CI, 0.29-0.88; P=0.011], especially in pemetrexed-based chemotherapy (HR 0.45, 95% CI, 0.24-0.86; P=0.011). PPFS was similar in patients with EGFR^T790M-positive tumors (median PPFS: 5.0 vs. 5.5 months, HR 0.80, 95% CI, 0.40-1.61; P=0.520) or EGFR^T790M-unknown tumors (median PPFS: 2.0 vs. 3.0 months, HR 1.40, 95% CI, 0.69-2.81; P=0.323).

Conclusions

Our study showed that continuous gefitinib plus chemotherapy, especially pemetrexed-based therapy, significantly improved PPFS in patients with EGFR^T790M-negative tumors as compared with chemotherapy alone, suggesting that this subtype of patients may derive clinical benefit from continuation of gefitinib treatment beyond progression.

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.

Natural history and clinical characteristics of multiple pulmonary nodules with ground glass opacity

BACKGROUND AND OBJECTIVE

Ground glass nodules (GGNs) are frequently encountered in the lungs. We report the natural history and characteristics of multiple GGNs, and propose a management plan for patients with multiple GGNs.

METHODS

We retrospectively analysed patients with GGNs that met the following criteria: (i) GGN diameter of 3 cm or less, (ii) ground glass opacity proportion of 50% or more and (iii) observation without treatment for ≥6 months. We evaluated size changes in computed tomography images. Two end points, 'incidence of growth at 36 months' and 'time to growth' were analysed using logistic regression models and Cox proportional hazards model.

RESULTS

Between April 2008 and December 2014, 187 patients fulfilled the inclusion criteria (78 (42%) had multiple lesions). Among the multiple-GGN patients, the median observation period was 45.5 months, 25 patients (32%) experienced GGN progression at 36 months and 4 patients (5.1%) after 36 months. Between the multiple and single GGNs, there were no significant differences in growth incidence at 36 months (P = 0.1), after 36 months (P = 0.6) or in time to growth (P = 0.3). Among patients with multiple GGNs who experienced one GGN growth, 41% of patients experienced residual GGN growth afterwards.

CONCLUSION

Patients with multiple GGNs showed a tendency to growth within the first 36 months, and a significant proportion of patients experienced multiple GGN progression. We suggest that the optimal observation period for patients with multiple GGNs is 36 months, but careful observation is needed after a lesion begins to grow.

Targeted sequencing may facilitate differential diagnostics of pulmonary tumours: a case series

Background

Histopathological diagnosis is important for prognostication and choice of treatment in patients with cancer in the lung. Metastases to the lungs are common and need to be distinguished from primary lung cancer. Furthermore, cases with synchronous or metachronous primary lung cancers (although infrequent) are often handled differently than cases with lung cancer with intrapulmonary metastasis or relapse, respectively. In some cases, morphology and immunohistochemical staining is not sufficient for certain diagnosis.

Methods

The present study included six cases where molecular genetic analysis in form of pyrosequencing or targeted next-generation sequencing was of value for certain diagnosis of selected tumours in the lung.

Results

Two of the included cases were rare metastases to the lung; colorectal cancer with IHC profile consistent with primary lung cancer and malignant adenomyoepithelioma of the breast, respectively, where molecular genetic analysis was of aid for proving the relationship to the primary tumour. The other four cases were multiple lung adenocarcinomas where molecular genetic analysis was of aid to distinguish between intrapulmonary metastasis and synchronous tumour.

Conclusions

Comparison of molecular genetic profile may be an important tool for determination of relationship between tumours in some situations and should always be considered in unclear cases. Further studies on concordance and discordance of molecular genetic profiles between spatially or temporally different tumours with common origin may be helpful for improved diagnostics of pulmonary tumours.

Bisphosphonates enhance antitumor effect of EGFR-TKIs in patients with advanced EGFR mutant NSCLC and bone metastases

Whether bisphosphonates could enhance the effect of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC) patients with EGFR mutation and bone metastases (BM) remains unknown. EGFR mutation status were collected from 1560 patients with NSCLC and BM. 356 NSCLC patients with EGFR mutation and BM were identified. Among them, 91 patients received EGFR-TKIs alone and 105 patients received EGFR-TKIs plus bisphosphonates as first-line therapy. Comparing to TKIs alone, EGFR-TKIs plus bisphosphonates had a statistically significant longer progression-free survival (PFS: 11.6 vs. 9.3 months; HR = 0.68, P = 0.009), while a similar overall survival (OS: 20.5 vs. 19.5 months; HR = 0.95, P = 0.743) in patients with EGFR-mutant NSCLC and BM. The incidence of skeletal-related events in combined group was numerically lower than that in EGFR-TKIs alone group (29.7% vs. 39.4%, P = 0.147). In multivariate analysis, EGFR mutation was found to be a significant independent prognostic factor for OS in NSCLC patients with BM (HR = 0.710, P = 0.021). In conclusion, EGFR mutation was the significant independent prognostic factor for OS and the addition of bisphosphonates to EGFR-TKIs could enhance the antitumor effect of EGFR-TKIs in patients with EGFR-mutant NSCLC and BM.

Correlation in histological subtypes with high resolution computed tomography signatures of early stage lung adenocarcinoma

BACKGROUND

Uncertainty remains on the association between image characteristics of the nodules in computed tomography (CT) scans and lung adenocarcinoma histopathologic subtypes. We aimed to estimate the correlation between preoperative high resolution computed tomography (HRCT) scan and postoperative histopathology of stage IA lung adenocarcinoma in East Asian Chinese population.

METHODS

We retrospectively reviewed the clinical records and HRCT images of 190 patients (106 female and 84 male) with resected, preoperatively untreated stage IA adenocarcinomas. The relationship between image characteristics of nodules at preoperative HRCT and their histological subtypes after resection were analyzed. The one-way ANOVA, chi-square test and logistic regression were used for analysis.

RESULTS

In 190 patients with stage IA lung adenocarcinoma, median tumor diameter was significantly lower in lepidic predominant invasive adenocarcinoma (LPA) (15.96±6.95 mm). Univariate analysis revealed that ground-glass opacity (GGO) proportion (P<0.001), margin (P<0.001), border definition (P=0.015), pleural retraction (P<0.001) and enhancement (P<0.001) had statistically significant differences in four histological subtypes. The multivariate analysis referenced for lepidic group which indicated that GGO proportion and pleural retraction were independent associated with acinar group (RR=4.221, 95% CI: 1.770-10.066, P=0.001; RR=0.380, 95% CI: 0.158-0.916, P=0.031, respectively). Male and whose nodule margin with spiculation or lobulation were prone to papillary predominant invasive adenocarcinoma (PPA) (RR=0.288, 95% CI: 0.090-0.920, P=0.036; RR=0.250, 95% CI: 0.070-0.887, P=0.032, respectively). GGO proportion and nodule margin were independent related factors in solid predominant invasive adenocarcinoma (SPA) (RR=13.338, 95% CI: 2.974-59.811, P=0.001; RR=0.097, 95% CI: 0.016-0.606, P=0.013, respectively).

CONCLUSIONS

Nodules with spiculation or lobulation and less GGO proportion are determinants of histological subtypes with poor prognosis in stage IA lung adenocarcinoma patients according to the 2011 histologic IASLC/ATS/ERS classification.

Pulmonary ground-glass opacity: computed tomography features, histopathology and molecular pathology

The incidence of pulmonary ground-glass opacity (GGO) lesions is increasing as a result of the widespread use of multislice spiral computed tomography (CT) and the low-dose CT screening for lung cancer detection. Besides benign lesions, GGOs can be a specific type of lung adenocarcinomas or their preinvasive lesions. Evaluation of pulmonary GGO and investigation of the correlation between CT imaging features and lung adenocarcinoma subtypes or driver genes can be helpful in confirming the diagnosis and in guiding the clinical management. Our review focuses on the pathologic characteristics of GGO detected at CT, involving histopathology and molecular pathology.

Clinicopathologic characteristics and outcomes of Chinese patients with non-small-cell lung cancer and BRAF mutation

BRAF mutation is one of the important driver oncogene in non‐small‐cell lung cancer (NSCLC). Data on Chinese patients with BRAF‐mutant NSCLC are inadequate. Hence, we conducted this study to investigate the clinicopathologic features and outcomes of Chinese patients with NSCLC and BRAF mutations. We identified patients with BRAF‐mutant NSCLC between January 2012 and April 2016. Patient characteristics and treatment outcomes were analyzed. In total, 1680 patients were included. Twenty‐eight (1.7%) patients harbored BRAF mutations. Compared to patients with non‐BRAF mutation, patients with BRAF mutations were associated with adenocarcinomas (89.3% vs. 70.6%, P = 0.048) and never smokers (78.6% vs. 56.7%, P = 0.019). There were no significant differences in the age, gender distribution, metastasis, or stage at first diagnosis between two groups. Response rates and progression‐free survival (PFS) were similar between patient with BRAF mutations and EGFR (5.6 vs. 5.8 months; P = 0.277) or KRAS (5.6 vs. 4.7 months; P = 0.741) mutations to first‐line chemotherapy. Compared to patients with non‐V600E mutations, patients with V600E‐mutated tumors had a shorter PFS to first‐line chemotherapy, although this did not reach statistical significance (5.2 vs. 6.4 months; P = 0.561). In multivariate analyses, only ECOG PS remained the independent predictor of overall survival (HR = 0.208; P = 0.004). In conclusion, BRAF mutation in Chinese patients with NSCLC was rare. BRAF mutation is more likely to be associated with adenocarcinoma and never smokers. BRAF mutations are not associated with enhanced chemosensitivity and novel and effective drugs inhibiting the BRAF pathway are in urgent need.

Uncommon EGFR mutations in a cohort of Chinese NSCLC patients and outcomes of first-line EGFR-TKIs and platinum-based chemotherapy

Objective

Data on the clinical activity of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in patients with non-small-cell lung cancer (NSCLC) and uncommon EGFR mutations remain insufficient. This study aimed to investigate the effect of first-line EGFR-TKIs or platinum-based chemotherapy in NSCLC patients with uncommon EGFR mutations.

Methods

We retrospectively enrolled 504 patients with EGFR-mutant NSCLC. The clinical characteristics and treatment outcomes were collected and compared between patients with common and uncommon EGFR-mutant NSCLC.

Results

Seventy patients (13.9%) harboring uncommon EGFR mutations were included. Thirty of these patients received EGFR-TKIs and 40 received platinum-based chemotherapy as first-line therapy. The objective response rate (ORR) and median progression-free survival (mPFS) of patients treated with TKIs in the uncommon mutation group was significantly inferior to that in the common mutation group (ORR: 23.3% vs. 51.8%, P=0.003; mPFS: 7.1 vs. 10.9 months, P<0.001). In the uncommon group, mPFS was similar between first-line EGFR-TKIs treatment and platinum-based chemotherapy (7.1vs. 6.1 months, P=0.893). In patients with EGFR G719X or L861Q mutations, the mPFS was longer in the first-line EGFR-TKIs treatment group than in the chemotherapy group, but the difference was not statistically significant (G719X: 8.2 vs. 5.8 months, P=0.061; L861Q: 7.6 vs. 4.1 months, P=0.872). Multivariate analyses identified adenocarcinoma (P=0.003) as the independent predictive factor for PFS in patients with uncommon EGFR mutations who were treated with first-line EGFR-TKIs.

Conclusions

The current study demonstrated that the effect of first-line EGFR-TKIs was similar to that of platinum-based chemotherapy in patients with uncommon EGFR-mutant NSCLC. Adenocarcinoma was the independent predictive factor for PFS in uncommon EGFR-mutant NSCLC patients treated with first-line EGFR-TKIs.

Molecular Profiling and Survival of Completely Resected Primary Pulmonary Neuroendocrine Carcinoma

BACKGROUND

Currently, molecular profiles and prognosis of primary pulmonary neuroendocrine carcinoma (PNC) are poorly elucidated. The present study was designed to evaluate genomic abnormalities and survival in patients with primary PNC.

METHODS

Completely resected PNC samples were collected from Zhejiang Cancer Hospital during the period of 2008 to 2015. Nine driver genes, including 6 mutations (EGFR, KRAS, NRAS, PIK3CA, BRAF, and HER2) and 3 fusions (ALK, ROS1, and RET), were evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Survival analysis was conducted by the Kaplan-Meier method.

RESULTS

A total of 108 patients with pathologically confirmed PNC were enrolled. The types were pulmonary large-cell neuroendocrine carcinoma (PLCNC, n = 52), small-cell lung cancer (SCLC, n = 44), and carcinoid (n = 12). Twelve patients (11.1%) harbored genomic aberrations. The most frequent gene abnormalities in decreasing order were PIK3CA (n = 5, 4.6%), EGFR (n = 3, 2.8%), KRAS (n = 2, 1.9%), ALK (n = 1, 0.9%), and RET (n = 1, 0.9%). No ROS1, BRAF, NRAS, or HER2 mutation was detected. The frequencies of gene aberrations were 15.4%, 6.8%, and 8.3% in PLCNC, SCLC, and carcinoid, respectively. Survival differences existed among PLCNC, SCLC, and carcinoid groups (37.0 vs. 34.0 vs. not reached, P = .035); however, no difference existed between PLCNC and SCLC groups (P = .606).

CONCLUSIONS

Genomic abnormality is rare in patients with PNC and it is the most frequently observed in PLCNC.

Clinical implications of genetic heterogeneity in multifocal pulmonary adenocarcinomas

Multifocal pulmonary adenocarcinomas are increasingly encountered in clinical practice, in part due to the increased availability and improvement in the thoracic imaging. Recognized as a distinct entity in the upcoming 8^th edition of American Joint Commission on Cancer (AJCC) staging system, multifocal adenocarcinomas exhibit several unique features such as the characteristic appearance of multiple ground glass opacities or nodules in computerized tomography (CT). Recent studies have suggested that the vast majority of these malignant lesions are genetically independent even when occurring synchronously in a single patient. For instance, the pattern of epidermal growth factor receptor (EGFR) mutations in multifocal pulmonary adenocarcinomas can vary from one lesion to another. This observation has several important clinical implications. These include the potential need to perform multiple molecular tests on multiple lesions, the possible role of molecular marker such as EGFR mutation in the staging of questionable multiple lung cancers, and the justification for empirical use EGFR inhibitors for multifocal adenocarcinomas among high-prevalence population when no known mutation has been detected.