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

Clinical impacts of a micropapillary pattern in lung adenocarcinoma: a review

Lung adenocarcinoma with a micropapillary pattern (MPPAC) has recently drawn increased attention among researchers. Micropapillary-predominant adenocarcinoma (MPA), which is defined by micropapillary pattern (MPP), is the primary histological pattern observed semiquantitatively in 5% increments on resection specimens, and MPA was formally determined to be a new histological subtype according to the new multidisciplinary classification in 2011. According to published studies, MPPAC is most common in males and nonsmokers and is associated with lymphatic invasion, pleural invasion, and lymph node metastases. MPPAC often presents as part-solid and lobulated nodules in computed tomography scans. MPP tends to have a higher maximum standardized uptake value as determined by fluorodeoxyglucose positron emission tomography combined with computed tomography, indicating a high risk of recurrence. Molecular markers, including vimentin, napsin A, phosphorylated c-Met, cytoplasmic maspin, Notch-1, MUC1, and tumoral CD10, may have higher expression in MPPAC than other subtypes; conversely, markers such as MUC4 and surfactant apoprotein A have lower expression in MPPAC. MPPAC with EGFR mutations can benefit from treatment with EGFR tyrosine kinase inhibitors. Furthermore, a complete lobectomy may be more suitable than limited resection for MPPAC because of the low sensitivity of intraoperative frozen sections and the high risk of lymph node metastasis. MPA benefits more from adjuvant chemotherapy than do other histological subtypes, whereas MPA does not benefit from adjuvant radiotherapy. Of note, MPP is associated with poor prognosis in early-stage lung adenocarcinoma, but the prognostic value of MPP is controversial in advanced-stage lung adenocarcinoma.

Associations between the IASLC/ATS/ERS lung adenocarcinoma classification and EGFR and KRAS mutations

We sought to investigate the frequency of mutations in epidermal growth factor receptor (EGFR) and Kirsten-RAS (KRAS) by each pathological subtype for patients with resected pulmonary adenocarcinoma as defined by the IASLC/ATS/ERS classification. Histological examination determined the predominant subtype according to the IASLC/ATS/ERS classification. EGFR and KRAS mutations were determined by high-resolution melting and Sanger sequencing. Clinical data were collected from medical records and clinicians. The 178 consecutive patients consisted of 48% males, median age 68 years (range 20-87) and smoking history 78%. The tumour stage was I in 62%, II in 18% and III in 20%. The mutation rates were: EGFR 30%; KRAS 28%. The rate of EGFR mutations in the acinar predominant reference group (n=76), was 37%. The solid predominant subtype showed significantly fewer EGFR mutations [3/33 (9%), odds ratio 0.17 (0.05-0.61), p=0.007]. No differences in mutation rate were observed in other subtypes. No association was found between KRAS mutations and predominant histological subtype. Advanced stage and solid predominant subtype were negative prognostic factors. EGFR mutations can be present in adenocarcinoma of any predominant subtype, however rarely in solid predominant tumours. No association was found between KRAS mutation and the predominant histological subtype.

Differences in driver genes between smoking-related and non-smoking-related lung cancer in the Chinese population

Recently, non-smoking-related lung cancer was classified as an independent disease entity because it is different from tobacco-associated lung cancer. Non-smoking-related lung cancer occurs more often in women than men, and the predominant histological type is adenocarcinoma (ADC) rather than squamous cell carcinoma. Most of the driver gene alterations that have been identified in ADC in never-smokers include epidermal growth factor receptor mutations, KRAS mutations, echinoderm microtubule-associated protein like 4/anaplastic lymphoma kinase fusion, and ROS1 fusion, among others. Meanwhile, significant progress has been made in the treatment of ADC. However, in comparison with ADC, no such available molecular targets exist for smoking-associated lung cancer, for which treatment strategies are limited. Next-generation sequencing has been widely applied to the discovery of more genetic profiles of lung cancers. This review summarizes the differences between smoking-related and non-smoking-related lung cancer as follows: different somatic mutation burdens, C:G→A:T transversions, common and novel driver genes, and treatment strategies. Overall, smoking-related lung cancer is more complicated than non-smoking-related lung cancer. Furthermore, we review the prevalence of driver genes in smoking-associated and non-smoking-associated lung cancers in the Chinese population.

Molecular Epidemiology of EGFR Mutations in Asian Patients with Advanced Non-Small-Cell Lung Cancer of Adenocarcinoma Histology - Mainland China Subset Analysis of the PIONEER study

Epidermal growth factor receptor (EGFR) mutations are the strongest response predictors to EGFR tyrosine kinase inhibitors (TKI) therapy, but knowledge of the EGFR mutation frequency on lung adenocarcinoma is still limited to retrospective studies. The PIONEER study (NCT01185314) is a prospective molecular epidemiology study in Asian patients with newly diagnosed advanced lung adenocarcinoma, aiming to prospectively analyze EGFR mutation status in IIIB/IV treatment-naïve lung adenocarcinomas in Asia. We report the mainland China subset results. Eligible patients (≥20 yrs old, IIIB/IV adenocarcinoma and treatment-naïve) were registered in 17 hospitals in mainland China. EGFR was tested for mutations by amplification refractory mutation system using biopsy samples. Demographic and clinical characteristics were collected for subgroup analyses. A total of 747 patients were registered. Successful EGFR mutation analysis was performed in 741, with an overall mutation rate of 50.2%. The EGFR active mutation rate is 48.0% (with 1.3% of combined active and resistance mutations). Tobacco use (>30 pack-year vs. 0–10 pack-year, OR 0.27, 95%CI: 0.17–0.42) and regional lymph nodes involvement (N3 vs. N0, OR 0.47, 95%CI: 0.29–0.76) were independent predictors of EGFR mutation in multivariate analysis. However, even in regular smokers, the EGFR mutation frequency was 35.3%. The EGFR mutation frequency was similar between diverse biopsy sites and techniques. The overall EGFR mutation frequency of the mainland China subset was 50.2%, independently associated with the intensity of tobacco use and regional lymph nodes involvement. The relatively high frequency of EGFR mutations in the mainland China subset suggest that any effort to obtain tissue sample for EGFR mutation testing should be encouraged.

[Advances of Pulmonary Adenocarcinoma with Micropapillary Pattern]

伴微乳头结构(micropapillary pattern, MPP)肺腺癌是一种临床少见的具有高度侵袭性的恶性肿瘤，近年来因其高死亡率被人们所重视。2011年关于肺腺癌的病理新分类将其作为一种独立的病理类型，此后针对该类肺癌个体化治疗的相关研究逐渐展开。近期的相关研究发现，伴MPP肺腺癌在转移机制、临床病理学、影像学、治疗及预后方面具有显著异质性。本文对伴MPP肺腺癌转移机制及相关临床研究进展进行探讨。

Epidermal growth factor receptor gene mutation status and its association with clinical characteristics and tumor markers in non-small-cell lung cancer patients in Northwest China

This study was conducted to investigate the mutation status of epidermal growth factor receptor (EGFR) and its association with clinical characteristics and tumor markers in non-small-cell lung cancer (NSCLC) patients from the Xinjiang Uygur Autonomous Region in China. We enrolled 51 cases of NSCLC patients who received radical surgical treatment in the First Affiliated Hospital of Xinjiang Medical University. Quantitative polymerase chain reaction was applied to detect exons 18, 19, 20 and 21 of the EGFR gene in tumor tissues. Multiple tumor markers, including carcinoembryonic antigen (CEA), were assessed preoperatively. The EGFR-positive rate was 49.02% (25/51), with a mutation rate of 8% (2/25) in exon 18, 52% (13/51) in exon 19, 40% (10/51) in exon 21 and no mutations in exon 20. The positive mutation rate in men and women was 37.5% (12/32) and 68.42%, respectively (13/19), with a statistically significantly higher rate in women (P<0.05). There were also statistically significant differences among adenocarcinoma, adenosquamous carcinoma and squamous cell carcinoma cases (P<0.05), while no statistically significant differences were observed in adenocarcinoma cases regarding degree of differentiation, lymph node metastasis and TNM stage (P>0.05). There was a statistically significant association between the EGFR gene mutation status and the preoperative serum CEA level (P<0.05). The mutation rate of the EGFR gene was 68.42% in female lung adenocarcinoma patients, which supports the application of targeted therapy in such cases. However, whether it is possible to obtain information regarding targeted therapy through measuring the level of serum CEA for NSCLC patients with unknown EGFR mutation status requires further investigation through related studies including a higher number of cases.

Diagnostic Mutation Profiling and Validation of Non-Small-Cell Lung Cancer Small Biopsy Samples using a High Throughput Platform

BACKGROUND

A single platform designed for the synchronous screening of multiple mutations can potentially enable molecular profiling in samples of limited tumor tissue. This approach is ideal for the assessment of advanced non-small-cell lung cancer (NSCLC) diagnostic specimens, which often comprise small biopsies. Therefore, we aimed in this study to validate the mass spectrometry-based Sequenom LungCarta panel and MassARRAY platform using DNA extracted from a single 5 μM formalin-fixed paraffin-embedded tissue section.

METHODS

Mutations, including those with an equivocal spectrum, detected in 90 cases of NSCLC (72 lung biopsies, 13 metastatic tissue biopsies, three resections, and two cytology samples) were validated by a combination of standard sequencing techniques, immunohistochemical staining for p53 protein, and next-generation sequencing with the TruSight Tumor panel.

RESULTS

Fifty-five mutations were diagnosed in 47 cases (52%) in the following genes: TP53 (22), KRAS (15), EGFR (5), MET (3), PIK3CA (3), STK11 (2), NRF-2 (2), EPHA5 (1), EPHA3 (1), and MAP2K1 (1). Of the 90 samples, one failed testing due to poor quality DNA. An additional 7 TP53 mutations were detected by next-generation sequencing, which facilitated the interpretation of p53 immunohistochemistry but required 5 × 10 μM tumor sections per sample tested.

CONCLUSIONS

The LungCarta panel is a sensitive method of screening for multiple alterations (214 mutations across 26 genes) and which optimizes the use of limited amounts of tumor DNA isolated from small specimens.

Lung cancer molecular epidemiology in China: recent trends

Lung cancer is both the most common diagnosed cancer and the leading cause of cancer related deaths in China. During the past three decades, the incidence and mortality of lung cancer in China are increasing rapidly. According to data from National Central Cancer Registry (NCCR) in 2010, the crude incidence of lung cancer in China was 46.08 per 100,000 population (61.86 per 100,000 men and 29.54 per 100,000 women), with an estimated over 600,000 new diagnosed lung cancer patients (416,333 males and 189,613 females). Meanwhile, the crude mortality of lung cancer in China was 37.00 per 100,000 population (50.04 per 100,000 men and 23.33 per 100,000 women). Consistent with the change in developed countries, adenocarcinoma has become the most predominant histological subtype of lung cancer in China. For the majority advanced non-small-cell lung cancer (NSCLC) patients, especially patients with adenocarcinoma, targeted therapy became increasing important in the treatment. Chinese researcher have done a lot work in terms of lung cancer molecular epidemiology, therefore, in this review, we further summarized the epidemiology of driver genes in NSCLC, hoping to help clinicians to better screen certain driver genes in China for treatment decisions.

The new histologic classification of lung primary adenocarcinoma subtypes is a reliable prognostic marker and identifies tumors with different mutation status: the experience of a French cohort

BACKGROUND

Histologic classification of lung adenocarcinoma subtype has a prognostic value in most studies. However, lung adenocarcinoma characteristics differ across countries. Here, we aimed at validating the prognostic value of this classification in a large French series of lung adenocarcinoma.

METHODS

We reviewed 407 consecutive lung adenocarcinomas operated on between 2001 and 2005 and reclassified them according to the International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification and subsequently graded them into low, intermediate, and high grade. We analyzed the relevance of this classification according to clinical, pathologic, and molecular analysis.

RESULTS

Patients (median age, 61 years; 288 men) underwent lobectomy (n = 378) or pneumonectomy (n = 29). Patients' overall survival at 5 and 10 years was 53.2% and 32.6%, respectively. Union for International Cancer Control stage distribution was 189 stage I, 104 stage II, 107 stage III, and seven stage IV. Low-grade tumor was found in one patient, intermediate grade in 275 patients, and high grade in 131 patients. KRAS and EGFR mutations were detected in 34% and 9.6%, respectively. Histologic grade was significantly correlated with extent of resection (P = .01), thyroid transcriptional factor-1 expression (P = .00000001), vascular emboli (P = .03), and EGFR mutations (P = .01). Mucinous adenocarcinomas were associated with KRAS mutations (P = .003). At univariate analysis, age, extent of resection, histologic grade, pleural invasion, vascular emboli, pathologic T and N, and stage were predictive of survival. At multivariate analysis, age (P = .0001), histologic grade (P = .03), and stage (P = .000003) were independent prognostic factors.

CONCLUSIONS

IASLC/ATS/ERS classification of lung adenocarcinomas predicts survival in French population. Histologic grade correlates with clinical, pathologic and molecular parameters suggesting different oncogenic pathways.

Comparison of clinical features, molecular alterations, and prognosis in morphological subgroups of lung invasive mucinous adenocarcinoma

PURPOSE

We performed this analysis to distinguish the differences in two subtypes of lung invasive mucinous adenocarcinoma (IMA) with different kinds of morphological performances, in clinicopathological and molecular features, as well as prognosis.

METHODS

On the basis of morphological performance, we divided lung IMAs into two subgroups, mucus-in-cell adenocarcinoma (MICA) and mucus-out-of-cell adenocarcinoma (MOCA). We investigated differences in clinicopathological characteristics, recurrence-free survival (RFS), overall survival (OS), and a spectrum of well-identified driver-gene mutations, including EGFR, KRAS, HER2, BRAF, ALK, ROS1, and RET, between the two subgroups.

RESULTS

Of 1,699 lung adenocarcinomas, 148 were identified as IMAs (97 MICAs and 51 MOCAs). The MICA patient group had significantly better RFS than did the MOCA group (39.4 months versus 33.0 months, respectively, log rank P=0.020) and significantly better OS (54.2 months versus 45.1 months, log rank P=0.034). There were no differences in RFS and OS between those with IMAs and those with mucus-negative adenocarcinomas. The frequency of the EGFR gene mutation was significantly higher in MOCAs than in MICAs (P<0.001). In contrast, the KRAS gene had a significantly higher mutational frequency in MICAs (P=0.01). MOCAs also had a significantly higher incidence of lymph-node metastasis (P<0.05).

CONCLUSION

To our knowledge, this study represents the first comparison of clinical features, molecular alterations, and prognosis in morphological subgroups of lung IMAs. Clinical and pathological features in conjunction with molecular data indicate that IMA should be divided into different subgroups.

The molecular background of mucinous carcinoma beyond MUC2

The increasing interest of the oncology community in tumour classification and prediction of outcome to targeted therapies has put emphasis on an improved identification of tumour types. Colorectal mucinous adenocarcinoma (MC) is a subtype that is characterized by the presence of abundant extracellular mucin that comprises at least 50% of the tumour volume and is found in 10–15% of colorectal cancer patients. MC development is poorly understood, however, the distinct clinical and pathological presentation of MC suggests a deviant development and molecular background. In this review we identify common molecular and genetic alterations in colorectal MC. MC is characterized by a high rate of MUC2 expression. Mutation rates in the therapeutically important RAS/RAF/MAPK and PI3K/AKT pathways are significantly higher in MC compared with non‐mucinous adenocarcinoma. Furthermore, mucinous adenocarcinoma shows higher rates of microsatellite instability and is more frequently of the CpG island methylator phenotype. Although the majority of MCs arise from the large intestine, this subtype also develops in other organs, such as the stomach, pancreas, biliary tract, ovary, breast and lung. We compared findings from colorectal MC with tumour characteristics of MCs from other organs. In these organs, MCs show different mutation rates in the RAS/RAF/MAPK and PI3K/AKT pathways as well, but a common mucinous pathway cannot be identified. Identification of conditions and molecular aberrations that are associated with MC generates insight into the aetiology of this subtype and improves understanding of resistance to therapies.

Implementing the new IASLC/ATS/ERS classification of lung adenocarcinomas: results from international and Chinese cohorts

A new histologic classification of lung adenocarcinoma was proposed by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) in 2011 to provide uniform terminology and diagnostic criteria for multidisciplinary strategic management. This classification proposed a comprehensive histologic subtyping (lepidic, acinar, papillary, micropapillary, and solid pattern) and a semi-quantitative assessment of histologic patterns (in 5% increments) in an effort to choose a single, predominant pattern in invasive adenocarcinomas. The prognostic value of this classification has been validated in large, independent cohorts from multiple countries. In patients who underwent curative-intent surgery, those with either an adenocarcinoma in situ (AIS) or a minimal invasive adenocarcinoma have nearly 100% disease-free survival and are designated "low grade tumors". For invasive adenocarcinomas, the acinar and papillary predominant histologic subtypes were usually designated as "intermediate grade" while the solid and micropapillary predominant histologic subtypes were designated "high grade" tumors; this was based on the statistic difference of overall survival. This classification, coupled with additional prognostic factors [nuclear grade, cribriform pattern, high Ki-67 labeling index, thyroid transcription factor-1 (TTF-1) immunohistochemistry, immune markers, and (18)F-fluorodeoxyglucose uptake on positron emission tomography (PET)] that we have published on, could further stratify patients into prognostic subgroups and may prove helpful for individual patient care. With regard to Chinese oncologists, the implementation of this new classification only requires hematoxylin and eosin (H&E) stained slides and basic pathologic training, both of which require no additional costs. More importantly, this new classification system could provide informative data for better selection and stratification of clinical trials and molecular studies.

Establishment and characterization of a singaporean chinese lung adenocarcinoma cell line with four copies of the epidermal growth factor receptor gene

We have established a lung adenocarcinoma cell line, ETCC016, from lung pleural effusion of a male Singaporean Chinese with advanced lung adenocarcinoma. The subject smoked 20 cigarettes per day for more than 30 years. The cell line arose from spontaneous transformation of cells grown in a collagen-coated culture dish. Transformed characteristics of the cell line include the ability to reach high confluency in a culture dish, low cell doubling time, ability to form colonies in soft agar, and ability to form solid tumor in immune-compromised SCID mice. Immunostaining showed that the cells originated from lung epithelial cells. Genomic analysis revealed a large amount of chromosomal aberrations (gain and loss of genetic materials, and loss of heterozygosity [LOH]), indicative of a long history of smoking. The cells have four copies of epidermal growth factor receptor (EGFR) and three copies of MYC, but have lost one copy of the RB1 gene. LOH was detected in TP53 and BRAF genes. There is no anaplastic lymphoma kinase (ALK) gene rearrangement. The ETCC016 lung adenocarcinoma cell line has demonstrated susceptibility towards inhibitors specific for EGFR/HER2 and ALK targets, but resistance to MYC-specific inhibitor. This cell line will be a useful model for further understanding of lung adenocarcinoma.

Oncogenic mutations are associated with histological subtypes but do not have an independent prognostic value in lung adenocarcinoma

Lung adenocarcinomas have diverse genetic and morphological backgrounds and are usually classified according to their distinct oncogenic mutations (or so-called driver mutations) and histological subtypes (the de novo classification proposed by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society [IASLC/ATS/ERS]). Although both these classifications are essential for personalized treatment, their integrated clinical effect remains unclear. Therefore, we analyzed 981 lung adenocarcinomas to detect the potential correlation and combined effect of oncogenic mutations and histological subtype on prognosis. Analysis for oncogenic mutations included the direct sequencing of EGFR, KRAS, HER2, BRAF, PIK3CA, ALK, and RET for oncogenic mutations/rearrangements, and a rereview of the IASLC/ATS/ERS classification was undertaken. Eligible tumors included 13 atypical adenomatous hyperplasia/adenocarcinoma in situ, 20 minimally invasive adenocarcinomas, 901 invasive adenocarcinomas, 44 invasive mucinous adenocarcinomas, and three other variants. The invasive mucinous adenocarcinomas had a lower prevalence of EGFR mutations but a higher prevalence of KRAS, ALK, and HER2 mutations than invasive adenocarcinomas. Smoking, a solid predominant pattern, and a mucinous component were independently associated with fewer EGFR mutations. The ALK rearrangements were more frequently observed in tumors with a minor mucinous component, while the KRAS mutations were more prevalent in smokers. In addition, 503 patients with stage I-IIIA tumors were analyzed for overall survival (OS) and relapse-free survival. The stage and histological pattern were independent predictors of relapse-free survival, and the pathological stage was the only independent predictor for the OS. Although patients with the EGFR mutations had better OS than those without the mutations, no oncogenic mutation was an independent predictor of survival. Oncogenic mutations were associated with the novel IASLC/ATS/ERS classification, which facilitates a morphology-based mutational analysis strategy. The combination of these two classifications might not increase the prognostic ability, but it provides essential information for personalized treatment.

Significance of persistent inflammation in respiratory disorders induced by nanoparticles

Pulmonary inflammation, especially persistent inflammation, has been found to play a key role in respiratory disorders induced by nanoparticles in animal models. In inhalation studies and instillation studies of nanomaterials, persistent inflammation is composed of neutrophils and alveolar macrophages, and its pathogenesis is related to chemokines such as the cytokine-induced neutrophil chemoattractant (CINC) family and macrophage inflammatory protein-1α and oxidant stress-related genes such as heme oxygenase-1 (HO-1). DNA damages occur chemically or physically by nanomaterials. Chemical and physical damage are associated with point mutation by free radicals and double strand brake, respectively. The failure of DNA repair and accumulation of mutations might occur when inflammation is prolonged, and finally normal cells could become malignant. These free radicals can not only damage cells but also induce signaling molecules containing immunoreaction. Nanoparticles and asbestos also induce the production of free radicals. In allergic responses, nanoparticles act as Th2 adjuvants to activate Th2 immune responses such as activation of eosinophil and induction of IgE. Taken together, the presence of persistent inflammation may contribute to the pathogenesis of a variety of diseases induced by nanomaterials.

[Driver genes and its clinical significance in non-small cell lung cancer]

With the development of molecular biology technology and the transforming patterns of drug research, guiding molecular targeted therapy according to the drive gene mutation spectrum in lung cancer has gradually become a reality. Definition of the mutation incidence and whether existing advantage population groups in non-small cell lung cancer (NSCLC) have important guiding significance in clinical practice. The purpose of this paper will draw a summary on the general characteristics, demographic features and clinical significance of driver genes in NSCLC.

ALK fusion and its association with other driver gene mutations in Finnish non-small cell lung cancer patients

Screening of anaplastic lymphoma tyrosine kinase (ALK) gene fusions in non-small cell lung cancer (NSCLC) patients enables the identification of the patients likely to benefit from ALK-targeted therapy. Our aim was to assess the prevalence of ALK fusion in Finnish NSCLC patients, which has not been reported earlier, and to study the presence of ALK fusion in relation to clinicopathological characteristics and other driver gene mutations. A total of 469 formalin-fixed paraffin-embedded tumor tissue specimens from Finnish NSCLC patients were screened for ALK fusion by immunohistochemistry (IHC). For confirmation of IHC results, fluorescence in situ hybridization (FISH) was conducted for 171 specimens. Next-generation sequencing was performed for all ALK-positive specimens to characterize the association of ALK fusion with mutations in targeted regions of 22 driver genes. Of the 469 tumors screened, 11 (2.3%) harbored an ALK fusion, including nine adenocarcinomas and two large cell carcinomas. The IHC results for all 11 ALK-positive and 160 random ALK-negative specimens were confirmed by FISH. ALK fusion was significantly associated with never/ex-light smoking history (P<0.001) and younger age (P=0.004). Seven ALK-positive tumors showed additional mutations; three in MET, one in MET and CTNNB1, two in TP53, and one in PIK3CA. Our results show that ALK fusion is an infrequent alteration in Finnish NSCLC patients. Although the majority of ALK-positive cases were adenocarcinomas, the fusion was also seen in large cell carcinomas. Further studies are needed to elucidate the clinical significance of the coexistence of ALK fusion with MET, TP53, CTNNB1, and PIK3CA mutations.

Multidriver mutation analysis in pulmonary mucinous adenocarcinoma in Taiwan: identification of a rare CD74-NRG1 translocation case

Several new chromosomal translocations resulting in driver fusion mutations have recently been discovered in non-small-cell lung cancer. The driver mutational patterns in pulmonary mucinous adenocarcinoma, a rare subtype of non-small-cell lung cancer, have not been well studied. A single-institute cohort study in Taiwan was performed to determine the mutations of epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), fusions of anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), and neuregulin 1 (NRG1) in patients diagnosed with pulmonary mucinous adenocarcinoma. We also examined NRG1 translocation in patients diagnosed as adenocarcinoma of other subtypes with wild-type EGFR, KRAS, ALK, and ROS1 genes. Surgical or biopsy specimens were collected from 13 patients with mucinous adenocarcinoma. Using the direct RNA sequencing method, we discovered a rare CD74-NRG1 fusion (8 %), an echinoderm microtubule-associated protein like 4 (EML4)-ALK fusion (17 %), and three KRAS mutations (25 %). No EGFR mutations or ROS1 rearrangements were detected. The rare CD74-NRG1 fusion positive patient presented with uncommon radiological features. We did not detect any CD74-NRG1 fusion in the 109 adenocarcinoma of other subtypes, which were all negative for EGFR, KRAS, ALK, and ROS1. The CD74-NRG1 fusion mutation is rare and may be exclusively present in patients with pulmonary mucinous adenocarcinoma. Patients harboring CD74-NRG1 positive tumors may present with uncommon imaging features.

Recent advances and clinical implications of the micropapillary histological subtype in lung adenocarcinomas

Micropapillary (MIP) histologic subtype included in the classification of lung adenocarcinomas (ADCs) is associated with both size- and stage-independent poor prognoses. MIP pattern in lung ADCs, even at small, early stages, correlates with high lymphovascular invasion, visceral pleural invasion and lymph node metastases. Recently, we reported that patients with a MIP component are at a higher risk of locoregional recurrence after limited resection. Identification of a MIP pattern is only possible with permanent pathologic sections; preoperative imaging, cytology or intraoperative frozen section specimens remain unreliable. The intermixed, heterogenous morphology of lung ADC presents a technical challenge in investigating the molecular biology of cells with MIP morphology. A comprehensive understanding of the biology of MIP morphology is vital for therapeutic interventions.

FGFR1/3 tyrosine kinase fusions define a unique molecular subtype of non-small cell lung cancer

PURPOSE

The fibroblast growth factor receptor (FGFR)-3 fusion genes have been recently demonstrated in a subset of non-small cell lung cancer (NSCLC). To aid in identification and treatment of these patients, we examined the frequency, clinicopathologic characteristics, and treatment outcomes of patients who had NSCLC with or without FGFR fusions.

EXPERIMENTAL DESIGN

Fourteen known FGFR fusion variants, including FGFR1, FGFR2, and FGFR3, were detected by RT-PCR and verified by direct sequencing in 1,328 patients with NSCLC. All patients were also analyzed for mutations in EGFR, KRAS, HER2, BRAF, ALK, RET, and ROS1. Clinical characteristics, including age, sex, smoking status, stage, subtypes of lung adenocarcinoma, relapse-free survival, and overall survival, were collected.

RESULTS

Of 1,328 tumors screened, two (0.2%) were BAG4-FGFR1 fusion and 15 (1.1%) were FGFR3-TACC3 fusion. Six of 1,016 patients with lung adenocarcinoma were FGFR3-TACC3 fusions and 11 of 312 lung squamous cell carcinoma harbored BAG4-FGFR1 or FGFR3-TACC3 fusions. Compared with the FGFR fusion-negative group, patients with FGFR fusions were more likely to be smokers (94.1%, 16 of 17 patients, P < 0.001), significantly associated with larger tumor (>3 cm; 88.2%, 15 of 17 patients, P < 0.001) and with a tendency to be more poorly differentiated (53.9%, nine of 17 patients, P = 0.095).

CONCLUSIONS

FGFR fusions define a molecular subset of NSCLC with distinct clinical characteristics. FGFR is a druggable target and patients with FGFR fusions may benefit from FGFR-targeted therapy, which needs further clinical investigation.

Epidermal growth factor receptor (EGFR) mutations as biomarker for head and neck squamous cell carcinomas (HNSCC)

CONTEXT

Mutations in tyrosine kinase domain (TK) of epidermal growth factor receptor (EGFR) lead to signalling interruptions in several cancers.

OBJECTIVE

To understand EGFR mutations in head and neck squamous cell carcinomas (HNSCC), and their role as biomarkers.

METHODS

Screened 129 HNSCC patients and 150 controls for mutations in the TK domain using polymerase chain reaction (PCR), single strand confirmatory polymorphism (SSCP) and sequencing.

RESULTS

81.39% of HNSCC had four mutations: G2155C, G2176A, C2188G and G2471A among these two mutations were also reported in other cancers where as two novel mutations are being reported for the first time in HNSCC. Mutational frequency was significantly associated with an advanced stage of HNSCC, habits of tobacco/alcohol and ages above 49 years.

CONCLUSION

EGFR single nucleotide polymorphisms could be useful biomarkers of HNSCC.

Peripheral lung adenocarcinomas with KRAS mutations are more likely to invade visceral pleura

CONTEXT

Kirsten-RAS (KRAS) mutations play an important role in the carcinogenesis of a subset of lung adenocarcinomas and are associated with poorer prognosis.

OBJECTIVE

To investigate the relationship of KRAS mutation status to the histologic subtype of adenocarcinoma according to the recent classification, patient demographics, tumor size, predominant histologic subtype, nodal status, and visceral pleural invasion, in an attempt to uncover the reason for the worse prognosis associated with KRAS mutation.

DESIGN

A total of 187 consecutive resected lung adenocarcinomas from our institution from 2008 to 2011 that were diagnosed according to the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification and screened for KRAS mutations were included in the study.

RESULTS

A total of 32% of the adenocarcinomas harbored the KRAS mutation. The median age in the KRAS mutation group was 69 years (range, 43-86 years), and male to female ratio was 1:2.3. The proportion of heavy smokers was significantly higher in tumors with KRAS mutation compared with wild type (83% versus 62%; P = .01). A total of 27% of tumors with KRAS mutation had pleural invasion versus 11% of tumors without KRAS mutation (P = .009). A total of 59 tumor samples were positive for KRAS mutation (25 for G12C, 14 for G12A, 8 for G12V, 7 for G12D, 3 for G12S, and 1 for G12T), and only 3 tumors harbored codon 13 mutations (G13C). Two tumors had double mutations.

CONCLUSIONS

KRAS mutations are more common in heavy smokers, and lung adenocarcinomas with KRAS mutation are more likely to invade the visceral pleura. Increased frequency of visceral pleural invasion may explain in part the worse prognosis associated with KRAS mutations.

Prevalence of driver mutations in non-small-cell lung cancers in the People's Republic of China

Lung cancer is a leading cause of cancer-related mortality worldwide and in the People’s Republic of China. Recently, the pathological proportions of the various forms of lung cancer have changed. A shift to a preponderance of adenocarcinoma at the expense of squamous cell carcinoma is observable. Treatment decisions have historically been based on tumor histology, and evolution of our molecular understanding of cancer has led to development of targeted therapeutic agents. It is essential to further understand mutations that drive cancer development (driver mutations) in relevant genes and their effects on cancer cell proliferation and survival. The epidemiology of lung cancer in the People’s Republic of China has been extensively reviewed elsewhere. However, molecular epidemiological data from mainland China are scarce. Consequently, we herein review the prevalence of driver mutations in Chinese patients.

Association of Merkel cell polyomavirus infection with EGFR mutation status in Chinese non-small cell lung cancer patients

OBJECTIVES

Female lung cancer patients with no smoking habit and non-mucinous adenocarcinoma have a higher rate of epidermal growth factor receptor (EGFR) gene mutations, which is related to tyrosine kinase inhibitors (TKIs) sensitivity. Unfortunately the cause of EGFR gene mutations is still elusive. In this study, we search for the association between Merkel cell polyomavirus (MCPyV) infection and EGFR gene mutations.

MATERIALS AND METHODS

We studied 189 non-small cell lung cancer (NSCLC) samples for the presence of MCPyV large T (LT) DNA, LT antigen and EGFR hotspot mutations. Clinicopathological parameters of this cohort were also analyzed.

RESULTS

Thirty out of 163 adenocarcinoma and 2 out of 18 squamous cell carcinoma were found to have MCPyV LT DNA by PCR. Immunostaining also showed LT protein expression in most of the DNA positive samples. EGFR mutations were more frequently detected in female (P=0.009) and non-smoking patients (P=0.0001). Furthermore, a significant association between MCPyV infection and EGFR mutations was found (P=0.001).

CONCLUSION

Our study shows that MCPyV LT DNA is present in a subgroup of NSCLC, which is significantly correlated with EGFR mutations. To the best of our knowledge, this is the first study to find an association between MCPyV infection and EGFR hotspot mutations. These results support the possibility that MCPyV has a partial role in the carcinogenesis of NSCLC in a subgroup of patients.

[Next-generation sequencing for lung cancer]

肺癌在生物学上具有侵袭性，并且是癌症相关死亡的主要原因。根据临床特征、预后、对治疗的反应和耐受性，每一例肺癌患者的进展均是独特的。传统上基于毛细管的单基因测序的第一代技术（如Sanger测序法）已被允许大量平行测序且成本更低、通量更高的下一代测序技术（next-generation sequencing, NGS）所替代。与传统方法相比，NGS技术取得显著进步。我们希望这些方法可全面地解释癌症全球图谱，并提供更多信息以满足个体化用药的需求。本综述包括对不同NGS技术的简要说明，NGS在肺癌研究进展中的应用和重要发现的总结，包括对已知靶基因（EGFR 、ALK 和KRAS ）的进一步探索、其它肺癌突变的鉴定和癌症基因组研究的全局协调。

Next-generation sequencing for lung cancer

Lung cancer is biologically aggressive and is the leading cause of cancer-related deaths. The development of lung cancer is unique in each patient according to clinical characterizations, prognosis, response and tolerance to treatment. Traditional capillary-based single-gene sequencing by a first-generation technique (known as Sanger sequencing) has been replaced by next-generation sequencing (NGS) since it allows massive parallel sequencing with lower cost and higher throughput. The NGS approach has made remarkable advances compared with traditional methods. We expect these methodologies to comprehensively interpret the global landscape of cancer and provide more information to fulfill the needs of personalized medicine. This review covers a brief introduction and summary on various NGS technologies, applications and important findings by NGS in lung cancer advances, including further discoveries in previously known target genes (EGFR, ALK and KRAS), the identification of additional lung cancer mutations and the global coordination of cancer genome studies.

Advances in cytopathology for lung cancer: the impact and challenges of new technologies

Despite recent advances in treatment modalities, the survival rate of patients with lung cancer has not significantly improved. Therefore, new avenues are being explored in the era of evolving personalized patient management by early detection. Cytology is now the mainstay to address the diagnostic needs of pulmonary malignancies. Cytology specimens deliver diagnostic results equivalent to tissue biopsies. Fine-needle aspirations are equally useful to perform diagnostic, predictive, and prognostic immunohistochemical markers and molecular analysis. This article reviews the main new technologies that produced this revolution. The new role of the cytopathologist in this time of interdisciplinary care is also discussed.