Comparison of small biopsy specimens and surgical specimens for the detection of EGFR mutations and EML4-ALK in non-small-cell lung cancer

ALK-rearranged squamous cell carcinoma of the lung

BACKGROUND

ALK rearrangement is a very rare subset of squamous cell carcinoma (SCC) and one of the clinical features in patients is lack of data. Here, we report eight patients diagnosed with SCC of the lung harboring ALK rearrangement.

METHODS

We collected primary NSCLC samples at the Beijing Chest Hospital between January 2012 and December 2018 for Ventana (D5F3) immunohistochemical detection. Among the 148 patients was diagnosed ALK-rearranged non small cell lung cancer (NSCLC), only eight cases was SCC. We collected patients information from electronic patent records (EPRs).

RESULTS

The eight cases of SCC were diagnosed by immunohistochemistry (IHC). Two were given crizotinib as second-line therapy. One patient had stable disease (SD) and progression-free survival (PFS) of six months. The other patient had progressive disease (PD) but PFS was only one month. The side effects were tolerable. This report identified 31 cases of ALK rearrangement in SCC patients from a literature search (including the eight patients in this study). These fusion genes are often seen in a younger age group (mean age: 55.6 years) and non-smokers (18/31, 58.1%). A total of 20 cases received an ALK inhibitor as first- or second-line treatment which included 11 with a partial response (PR), four with SD, and five with PD. The DCR and ORR was 75.0% (15/20) and 55.0% (11/20), respectively. The median duration time of therapy was 6.4 ± 4.4 months.

CONCLUSIONS

Patients with ALK-rearranged SCC obtained clinical benefit from ALK-inhibitor therapy, especially those who were non-smokers and whose tumors had been identified by IHC+/FISH+.

Role of downregulated ADARB1 in lung squamous cell carcinoma

Non‑small cell lung cancer (NSCLC) is prevalent worldwide. Lung squamous cell carcinoma (LUSC) is one of the main subtypes of NSCLC yet, currently, few biomarkers are available for the diagnosis of LUSC. The present study aimed to investigate the expression and role of adenosine deaminase RNA specific B1 (ADARB1) in lung squamous cell carcinoma (LUSC). Integrative bioinformatics analysis was used to identify the effects of ADARB1 expression on the occurrence and prognosis of LUSC. The expression of ADARB1 was further examined by immunohistochemistry (IHC). Bioinformatics analysis suggested that ADARB1 was downregulated in LUSC, serving as a potential tumor suppressor, and these results were verified by IHC performed on a lung cancer tissue array. Clinical studies suggested that ADARB1 expression and methylation levels were significantly associated with patient characteristics in LUSC. Moreover, ADARB1 global methylation levels were upregulated in LUSC tissues compared with normal lung tissues. Higher methylation levels of cg24063645 were associated with shorter overall survival time of patients with LUSC. A negative correlation was identified between ADARB1 and epidermal growth factor receptor (EGFR) expression in LUSC. Using the Gene Expression Omnibus database, it was suggested that the expression of ADARB1 in LUSC was significantly different compared with that in lung adenocarcinoma. Furthermore, protein‑protein interactions were studied and a biological process annotation analysis was conducted. The present study suggested that ADARB1 was downregulated in LUSC; therefore, ADARB1 may serve as a specific biomarker and a potential therapeutic target for LUSC.

Comparison of EML4-ALK fusion gene positive rate in different detection methods and samples of non-small cell lung cancer

Objective: To evaluate differences of EML4-ALK positive rates in tissues samples between immunohistochemistry, reverse transcriptase polymerase chain reaction and the next-generation sequencing method. Besides, to compare the differences of EML4-ALK positive rates in blood samples and tissue samples by next-generation sequencing. The results provide a basis for the selection of a suitable EML4-ALK fusion gene detection method. Methods: Immunohistochemistry analysis of EML4-ALK in tumors was performed on samples from 2631 patients with non-small cell lung cancer. The mutation of EML4-ALK in the tissue samples of 399 patients with non-small cell lung cancer was detected by reverse transcription polymerase chain reaction. Next-generation sequencing was used to detect the mutation of EML4-ALK in 1505 non-small cell lung cancer patients, including 1208 tissue samples and 297 blood samples. Results: The positive incidence of EML4-ALK by immunohistochemistry was 7.11% (187/2631). Histologically, 9.51% (170/1787) of the samples were lung adenocarcinomas, and 2.01% (17/844) were squamous cell carcinomas. The positive rate of EML4-ALK was 8.52% (34/399) in 399 patients with non-small cell lung cancer, as detected by reverse transcription polymerase chain reaction; the mutation rate of adenocarcinoma was 11.62% (33/284), and the mutation rate of squamous cell carcinoma was 0.86% (1/115). In 1208 patients with non-small cell lung cancer with tissue samples, the positive rate of EML4-ALK was 4.88% (59/1208), as determined by next-generation sequencing, the mutation rate of adenocarcinoma was 5.84% (58/994), and the mutation rate of squamous cell carcinoma was 0.47% (1/214). The positive rate of EML4-ALK detected by reverse transcription polymerase chain reaction was higher than that detected by immunohistochemistry. Compared with the next-generation sequencing results, the positive rates of EML4-ALK detected by immunohistochemistry and reverse transcription polymerase chain reaction were higher, and the differences were significant (p<0.05). In blood samples from 297 patients with non-small cell lung cancer, the positive rate of EML4-ALK detected by next-generation sequencing was 3.70% (11/297), the mutation rate of adenocarcinoma was 3.82% (10/262), and the mutation rate of squamous cell carcinoma was 2.86% (1/35). The EML4-ALK positive rate of the tissue samples was thus higher than that of the blood biopsy samples. Conclusion: Among the three methods for detecting EML4-ALK, reverse transcription polymerase chain reaction has the highest positive rate, followed by immunohistochemistry, and next-generation sequencing has the lowest positive rate. The positive detection rate of EML4-ALK in tissue samples by next-generation sequencing was higher than that in blood samples.

Cancer progression is mediated by proline catabolism in non-small cell lung cancer

Dysregulated metabolism contributes to cancer initiation and progression, but the key drivers of these pathways are just being discovered. Here, we report a critical role for proline catabolism in non-small cell lung cancer (NSCLC). Proline dehydrogenase (PRODH) is activated to reduce proline levels by the chromatin remodeling factor lymphoid-specific helicase (LSH), an epigenetic driver of NSCLC. PRODH promotes NSCLC tumorigenesis by inducing epithelial to mesenchymal transition (EMT) and IKKα-dependent inflammatory genes, including CXCL1, LCN2, and IL17C. Consistently, proline addition promotes the expression of these inflammatory genes, as well as EMT, tumor cell proliferation, and migration in vitro and tumor growth in vivo, while the depletion or inhibition of PRODH blocks these phenotypes. In summary, we reveal an essential metabolic pathway amenable to targeting in NSCLC.

Comparison of Epidermal Growth Factor Receptor Gene Mutations Identified Using Pleural Effusion and Primary Tumor Tissue Samples in Non-Small Cell Lung Cancer

BACKGROUND

Although the use of pleural effusion samples for epidermal growth factor receptor (EGFR) testing in lung cancer is increasing, the accuracy rate and effectiveness of identifying EGFR mutations using these samples, rather than primary tumor tissue samples, is not established.

MATERIALS AND METHODS

One hundred ninety-two advanced, non-small cell lung cancer patients were enrolled into this study. All patients had primary tumor tissue and corresponding pleural effusion samples, and we employed the Amplification Refractory Mutation System to detect EGFR gene mutations in these samples.

RESULT

The number of EGFR mutations detected in primary tumor tissue and pleural effusion samples was 119 (61.98%) and 113 (58.85%), respectively. The EGFR-mutation rate was significantly higher in female than in male patients, and in adenocarcinoma than in nonadenocarcinoma patients (P=0.000). Single mutations in exons 19 and 21 were the predominant observed mutation type, and the overall concordance rate of EGFR-mutation status between the 192 matched pleural effusion and primary tumor tissue samples was 86.98%.

CONCLUSIONS

We observed a high concordance rate between EGFR mutations identified using primary tumor tissue and corresponding pleural effusion samples by Amplification Refractory Mutation System. Thus, it is likely that pleural effusion sampling from advanced non-small cell lung cancer patients, especially those with adenocarcinoma, may be effective in EGFR-mutation screening.

Detecting EGFR mutations and ALK/ROS1 rearrangements in non-small cell lung cancer using malignant pleural effusion samples

Background

The study was conducted to evaluate the feasibility of using malignant pleural effusion (MPE) as a substitute specimen for genetic testing and to determine the significance of genetic profiling of MPE tumor cells to monitor non‐small cell lung cancer (NSCLC) progression and therapeutic response.

Methods

We selected 168 NSCLC patients with MPE. We extracted MPE and enriched tumor cells using a custom‐designed device. EGFR mutations and ALK/ROS1 fusions were then detected by quantitative real‐time PCR, and the results were used to guide targeted therapy. We investigated drug responses through imaging.

Results

MPE tumor cells were detected in all patients. EGFR mutations and ALK/ROS1 rearrangements were detected in biopsy samples, treated MPE, and untreated MPE. We found that treated MPE had higher sensitivity and specificity than biopsy or untreated MPE. Among the 26 EGFR inhibitor patients, 13 showed a partial response, 7 had progressive disease, and 6 showed stable disease. Among the 16 patients that received ALK/ROS1 inhibitors, 8 had a partial response, 4 had progressive disease, and 4 showed stable disease.

Conclusion

Our study provides a new, less invasive, and highly repeatable method of analyzing MPE tumor cells in NSCLC that facilitates precision medicine and genetic testing.

Mutational landscape and clonal diversity of pulmonary adenoid cystic carcinoma

Pulmonary adenoid cystic carcinoma is a rare and indolent lung malignancy, characterized by a protracted but unpredictable growth behavior. Currently, the treatment of PACC relies on surgery and local radiotherapy. However, treatment options for advanced PACC patients are limited. A larger number of studies demonstrated that advanced PACC patients obtained limited benefit from chemotherapy. Moreover, only a few case reports revealed PACC patients were candidates for target therapy. Therefore, there is an urgent need to develop novel therapies. Due to its rareness, its mutational landscape remains largely elusive. In this study, we performed capture-based ultra-deep sequencing on multiregional surgical specimens obtained from 8 PACC patients using a panel consisting of 295 cancer-related genes. Our data revealed distinctive mutational spectrum of PACC, which differed from non-small cell lung cancer and adenoid cystic carcinomas originated from other anatomical sites. PACC, lacking mutations in a majority of non-small cell lung cancer driver genes, has frequent mutations in genes participating in chromatin remodeling and NOTCH signaling pathway. We also elucidated spatial intra-tumoral heterogeneity, which varied among cases. Most mutations in chromatin remodelers were subclonal. Collectively, our findings elucidated molecular signature associated with PACC and highlighted the potential for epigenetic therapy in this disease.

Recurrence risk after preoperative biopsy in patients with resected early-stage non-small-cell lung cancer: a retrospective study

Background

Tumor cell dissemination after needle biopsy has been reported in a variety of malignancies, including non-small-cell lung cancer (NSCLC). However, there is little clinical evidence in regard to whether preoperative biopsy increases the risk of recurrence in completely resected NSCLC.

Patients and methods

A total of 322 patients diagnosed as pathological stage I NSCLC using intraoperative biopsy (IOB) (control group), preoperative percutaneous needle biopsy (PNB) or bronchoscopic biopsy were included in this study. Baseline characteristics were collected and compared. The disease-free survival (DFS) of patients was analyzed using Kaplan–Meier method. Subgroup analysis and Cox regression were performed to evaluate the effect of preoperative biopsy on recurrence risk with adjustment for potential confounders.

Results

Among these patients, 202 (63%) underwent IOB, 66 (20%) underwent PNB, and 54 (17%) underwent bronchoscopic biopsy. DFS of patients who had preoperative PNB or bronchoscopic biopsy was similar to those who had IOB (P=0.514 and 0.869). Neither preoperative PNB nor transbronchial biopsy significantly affected recurrence incidence across all the relevant subgroups. Furthermore, multivariate analysis showed that preoperative biopsy was not associated with increased recurrence risk in NSCLC patients with adjustment for confounders, while squamous cell carcinoma and adjuvant chemotherapy were associated with prolonged DFS.

Conclusion

Neither preoperative PNB nor bronchoscopic biopsy increased the recurrence risk in patients with resected stage I NSCLC, indicating that these procedures could be safely used for diagnosis of early-stage NSCLC.

Clinical features of squamous cell lung cancer with anaplastic lymphoma kinase (ALK)-rearrangement: a retrospective analysis and review

Anti-anaplastic lymphoma kinase (ALK)-targeted therapy dramatically improves therapeutic responses in patients with ALK-rearranged lung adenocarcinoma (Ad-LC). A few cases of squamous cell lung carcinoma (Sq-LC) with ALK rearrangement have been reported; however, the clinicopathological features and clinical outcomes following treatment with ALK inhibitors are unknown. We addressed this in the present study by retrospectively comparing the clinical characteristics of five patients with ALK-rearranged Sq-LC with those of patients with ALK-rearranged Ad-LC and by evaluating representative cases of ALK inhibitor responders and non-responders. The prevalence of ALK rearrangement in Sq-LCs was 1.36%. Progression-free survival (PFS) after initial treatment with crizotinib was significantly shorter in Sq-LC than in Ad-LC with ALK rearrangement (p = 0.033). Two ALK rearrangements assayed by fluorescence in situ hybridization (FISH)-positive/immunohistochemistry-negative cases did not respond to crizotinb, and PFS decreased following alectinib treatment of ALK-rearranged Sq-LC (p = 0.045). A rebiopsy revealed that responders to ceritinib harbored the L1196M mutation, which causes resistance to other ALK inhibitors. However, non-responders were resistant to all ALK inhibitors, despite the presence of ALK rearrangement in FISH-positive circulating tumor cells and circulating free DNA and absence of the ALK inhibitor resistance mutation. These results indicate that ALK inhibitors remain a reasonable therapeutic option for ALK-rearranged Sq-LC patients who have worse outcomes than ALK-rearranged Ad-LC patients and that resistance mechanisms are heterogeneous. Additionally, oncologists should be aware of the possibility of ALK-rearranged Sq-LC based on clinicopathological features, and plan second-line therapeutic strategies based on rebiopsy results in order to improve patient outcome.

SNCA Is a Functionally Low-Expressed Gene in Lung Adenocarcinoma

There is increasing evidence for the contribution of synuclein alpha (SNCA) to the etiology of neurological disorders, such as Parkinson's disease (PD). However, little is known about the detailed role of SNCA in human cancers, especially lung cancers. Here, we evaluated the effects of SNCA on the occurrence and prognosis of lung adenocarcinoma (ADC). Comprehensive bioinformatics analyses of data obtained from the Oncomine platform, the human protein atlas (HPA) project and the cancer cell line encyclopedia (CCLE) demonstrated that SNCA expression was significantly reduced in both ADC tissues and cancer cells. The results of relevant clinical studies indicated that down-regulation of SNCA was statistically correlated with shorter overall survival time and post-progression survival time. Through analysis of datasets obtained from the Gene Expression Omnibus database, significant low levels of SNCA were identified in cisplatin-resistant ADC cells. Moreover, small interfering RNA (siRNA)-mediated knockdown of protein tyrosine kinase 7 (PTK7) elevated the expression of SNCA in the ADC cell lines H1299 and H2009. Our work demonstrates that low levels of SNCA are specifically found in ADC and that this gene may be a potential therapeutic target for this subset of lung cancers. Determination of the role of SNCA in ADC biology would give us some insightful information for further investigations.

Homogeneity and High Concordance of ALK Translocation in Primary Lung Adenocarcinoma and Paired Lymph Node Metastasis

Translocation of anaplastic lymphoma kinase (ALK) gene is an important determinator for the response to ALK tyrosine kinase inhibitor (TKI) in non-small-cell lung cancer (NSCLC) patients. The existence of genetic heterogeneity will affect the results of molecular testing, especially in biopsy samples from primary or metastatic sites of patients with advanced stage NSCLC. We intended to explore the heterogeneity of ALK gene translocation in excision specimens and to examine the existence of discordance of ALK status between primary tumours and corresponding lymph node metastases. A total of 106 ALK positive lung adenocarcinoma cases were collected for assessment of intratumour heterogeneity of ALK gene translocation, which were stained by the fully automated Ventana ALK D5F3 immunohistochemistry (IHC) analysis. In addition, the ALK gene translocations were evaluated in a series of 53 primary tumours and their paired lymph node metastases using ALK D5F3 IHC staining. The concordance rate between primary tumours and paired metastatic lymph nodes was 100%. ALK status was homogeneous in lung adenocarcinoma samples and was generally stable during metastasis. Therefore, ALK gene translocation can be measured reliably in material from either primary or metastatic tumours in lung adenocarcinoma patients.