Massive parallel sequencing and digital gene expression analysis reveals potential mechanisms to overcome therapy resistance in pulmonary neuroendocrine tumors.

Background: Lung cancer is the leading cause of cancer-related deaths worldwide. 25% show neuroendocrine differentiation (typical/atypical carcinoids, large-/small-cell neuroendocrine carcinomas). Carcinoids present with long survival rates, but metastatic carcinoids correlate with decreased survival and are commonly insensitive to standard chemotherapy or radiation. Therefore, novel therapeutic strategies are urgently needed. Material and methods: 70 representative tumor specimens were used for next-generation sequencing analysis of 14 genes related to therapy response. Additionally, mRNA-expression profiles of 60 matching samples were determined for 13 selected drug targets by using the NanoString nCounter technology. Results: A number of features known to sensitize tumors for different targeted therapies could be identified, which hopefully improve the clinical management of this subgroup of lung neoplasias. In particular, EGFR expression was observed in the investigated tumors in a noteworthy manner. Additionally, MDM2 was strongly expressed in the majority of all samples whereas the expression of its physiological inhibitor, CDKN2A, was nearly absent in all low-grade tumors. TP53 showed a high frequency of variants in high-grade tumors but mutations were rare in carcinoids. Conclusion: Based on our results, therapeutic approaches with MDM2-inhibitors and monoclonal anti-EGFR antibodies may be promising in pulmonary carcinoid tumors.

Clinicopathological features and relation between anaplastic lymphoma kinase (ALK) mutation and histological subtype of lung adenocarcinoma in Eastern European Caucasian population.

Introduction: The incidence of echinoderm microtubule-associated protein-like4-anaplastic lymphoma kinase (EML4-ALK) mutation among surgically treated patients with adenocarcinoma of the lung of the Eastern European ethnicity is underreported. The aim of this trial was the determination of EML4-ALK mutation frequency in investigated population, and the evaluation of correlations between lung adenocarcinoma subtype and clinical characteristics with mutation status. Patients and methods: This was a prospective trial which included 195 patients with adenocarcinoma of the lung who underwent surgical treatment. ALK mutation screening was performed by immunohistochemistry (IHC). IHC scores of 2+ and 3+ were regarded as positive. Confirmatory FISH was performed in all IHC positive and in 2:1 ratio in negative patients. Results: Overall ALK mutation rate established by IHC was 6.2%, while FISH confirmed rate of 5.1%. The FISH confirmed ALK positivity in 7.6% Hungarians, 5.5% Serbians, and 6.6% Slovakians. Acinar subtype of adenocarcinoma of the lung was significantly (p=0.02) related to EML4-ALK positive mutation status. Most of the patients were males (56.9%), smokers (50.8%), or former smokers (28.7%) with acinar (55.4%) or solid (35.9%) adenocarcinoma of the lung. Sensitivity and specificity of IHC were 100% and 98.9% respectively. Conclusions: ALK mutation rate in surgically treated patients with adenocarcinoma of the lung was found to be 6.2% by IHC and 5.1% by FISH. Acinar subtype of the adenocarcinoma of the lung was significantly related to ALK positive mutation.

Screening of Pleural Mesotheliomas for DNA-damage Repair Players by Digital Gene Expression Analysis Can Enhance Clinical Management of Patients Receiving Platin-Based Chemotherapy.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumour leading to a dismal prognosis. Multimodality therapy consisting of platinum-based chemotherapy is the treatment of choice. The reasons for the rather poor efficacy of platinum compounds remain largely unknown. MATERIAL AND METHODS: For this exploratory mRNA study, 24 FFPE tumour specimens were screened by digital gene expression analysis. Based on data from preliminary experiments and recent literature, a total of 366 mRNAs were investigated using a Custom CodeSet from NanoString. All statistical analyses were calculated with the R i386 statistical programming environment. RESULTS: CDC25A and PARP1 gene expression were correlated with lymph node spread, BRCA1 and TP73 expression levels with higher IMIG stage. NTHL1 and XRCC3 expression was associated with TNM stage. CHECK1 as well as XRCC2 expression levels were correlated with tumour progression in the overall cohort of patients. CDKN2A and MLH1 gene expression influenced overall survival in this collective. In the adjuvant treated cohort only, CDKN2A, CHEK1 as well as ERCC1 were significantly associated with overall survival. Furthermore, TP73 expression was associated with progression in this subgroup. CONCLUSION: DNA-damage response plays a crucial role in response to platin-based chemotherapeutic regimes. In particular, CHEK1, XRCC2 and TP73 are strongly associated with tumour progression. ERCC1, MLH1, CDKN2A and most promising CHEK1 are prognostic markers for OS in MPM. TP73, CDKN2A, CHEK1 and ERCC1 seem to be also predictive markers in adjuvant treated MPMs. After a prospective validation, these markers may improve clinical and pathological practice, finally leading to a patients' benefit by an enhanced clinical management.