Neuroendocrine tumors of the lung

Surgical treatment of low and intermediate grade lung net

Background

Carcinoids now constitute complex tumours which require a multidisciplinary approach and long-term follow-up. Surgical intervention is nowadays confirmed as the mainstay of treatment.

Methods

From 1980 to 2015, EMETNE-SEPAR collected 1,339 patients treated surgically for bronchial carcinoid (1,154 typical and 185 atypical carcinoids). Standard and conservative procedures were considered with regard to surgical approach. All the patients with carcinoid were pathologically coded following the standards of the 7^th edition 2009 TNM lung cancer staging. Statistical analyses were performed in order to determine whether histology, nodal affectation and surgical technique were associated with significant differences in survival, presence of metastases and local recurrence.

Results

The influence of the surgical procedure on overall survival, the presence of metastases and local recurrence were demonstrated as no significant in our sample in central tumours (P>0.05). Sublobar resections in peripheral tumours are related to a decrease in survival in typical carcinoids (P=0.008) with nodal involvement and an increased number of recurrences in atypical carcinoids without nodal involvement (P=0.018).

Conclusions

In central typical carcinoid, the use of lung-sparing bronchoplastic techniques could influence local recurrence in some cases. This observation demands the intraoperative pathologic verification of an adequate surgical margin by frozen section. Peripheral typical carcinoids have been surgically treated, occasionally, by sublobar resection. However, in peripheral atypical carcinoid after a limited sublobar resection the observed increase of the probability of local recurrence makes it, in our opinion, not advisable.

The significance of histology: typical and atypical bronchial carcinoids

The aim of this study is to assess in bronchial carcinoid tumors, the prognostic factors in relation to the histology that would determine their most appropriate therapy. The histologic aggressiveness is a determining factor in tumor size and nodal involvement in these tumors. The knowledge of the histologic limits of typical and atypical carcinoid contributes to the recognition of a better valuation of the proportional significance that nodal involvement and histologic grade have in a tumor's prognosis.

Down-regulation of RE-1 silencing transcription factor (REST) in advanced prostate cancer by hypoxia-induced miR-106b~25

Clinically aggressive prostate cancer (PCa) is linked to androgen resistance, metastasis, and expression of neuroendocrine markers. To understand mechanism(s) of neuroendocrine differentiation (NED) of PCa epithelia, we compared neuronal differentiation occurring during embryogenesis, in primary cultures of neural crest (NC) cells, and NED in PCa cell lines (LNCaP and PC3). We demonstrate, hypoxia promotes neuronal and neuroendocrine differentiation of NC cells and PCa cells, respectively, by inducing the miR-106 b~25 cluster. In turn, miR-106b~25 comprised of miR-106b, miR-93 and miR-25, down-regulates the transcriptional repressor REST, which represses neuron-specific protein-coding and miRNA genes. In prostate tumors of high Gleason score (≥ 8), an inverse trend was observed between REST and miR-106b~25 induction. Employing miRNA PCR arrays, we identified miRNAs up-regulated by hypoxia in LNCaP cells and REST-knockdown in NC cells. Significantly, a subset of miRNAs (miR-9, miR-25, miR-30d and miR302b) is up-regulated in high Gleason score (≥ 8) PCa, suggesting a mechanism by which NED contributes to PCa malignancy. We propose that loss of REST and induction of this set of microRNAs can serve as potential novel clinical markers of advanced PCa.

Phosphatidylinositol-3-kinase α catalytic subunit gene somatic mutations in bronchopulmonary neuroendocrine tumours

Bronchopulmonary neuroendocrine tumours (BP-NETs) comprise a large spectrum of tumours including typical carcinoids (TCs), atypical carcinoids (ACs), large-cell neuroendocrine carcinomas (LCNECs) and small-cell lung carcinomas (SCLCs) that exhibit considerably different biological aggressiveness and clinical behaviours. The phosphatidylinositol-3-kinase α catalytic subunit (PIK3CA) gene is known to be involved in the pathogenesis of several types of human cancers through gene amplification, deletions or somatic missense mutations within the helical and catalytic domains. However, the PIK3CA gene status in BP-NETs has yet to be explored. This study aimed to investigate the PIK3CA gene status in a large series of BP-NETs by direct gene sequencing and to analyse its correlation with the main clinicopathological parameters. To the best of our knowledge, we demonstrated for the first time a high frequency of somatic missense mutations (23.2%) in the PIK3CA gene in a series of 190 BP-NETs, including 75 TCs, 23 ACs, 17 LCNECs and 75 SCLCs. The frequency of the PIK3CA gene mutation in the kinase domain was higher (17.9%) than that in the helical domain (5.3%). When the mutational status of the PIK3CA gene was compared with the main clinical and pathological characteristics of the BP-NET patients, we found a significant association between PIK3CA gene mutations and BP-NET histology (p=0.011). Interestingly, the frequency of PIK3CA gene mutations increased with the biological aggressiveness of all BP-NETs, except LCNECs. In conclusion, our results suggest that PIK3CA gene mutations may play a key role in tumourigenesis and aggressiveness of BP-NETs. The PIK3CA gene may represent a favourable candidate for an effective therapeutic strategy in the treatment of patients with BP-NETs.

Multimodality treatment for sinonasal neuroendocrine carcinoma

BACKGROUND

Neuroendocrine carcinoma (NEC) of the paranasal sinuses is rare, accounting for 5% of sinonasal malignancies. The purpose of this study was to assess prognostic factors and survival rates for sinonasal NEC.

METHODS

A retrospective review of patients with NEC treated from 1990 to 2004 was performed. Patient demographics, TNM classification, treatment modality, recurrences, and survival were evaluated.

RESULTS

NEC was identified in 28 patients; the most common primary site was the ethmoid sinuses. Most patients presented with advanced tumors; few had regional or distant metastasis. Local recurrence rate was 21%. Five-year overall survival (OS) and disease-specific survival (DSS) rates were 65% and 78%, respectively. Response to chemotherapy predicted for improved survival, although no differences in outcomes were noted between definitive management strategies.

CONCLUSION

NEC of the paranasal sinuses is an exceedingly rare malignancy of the paranasal sinuses. Our data suggests definitive management with surgery or radiotherapy offers durable control. The response to chemotherapy may predict for overall outcomes.

Toona sinensis extracts induced cell cycle arrest and apoptosis in the human lung large cell carcinoma

Toona sinensis extracts have been shown to exhibit anti-cancer effects in human ovarian cancer cell lines, human promyelocytic leukemia cells and human lung adenocarcinoma. Its safety has also been confirmed in animal studies. However, its anti-cancer properties in human lung large cell carcinoma have not been studied. Here, we used a powder obtained by freeze-drying the supernatant of centrifuged crude extract from Toona sinensis leaves (TSL-1) to treat the human lung carcinoma cell line H661. Cell viability was evaluated by the 3-(4-,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay. Flow cytometry analysis revealed that TSL-1 blocked H661 cell cycle progression. Western blot analysis showed decreased expression of cell cycle proteins that promote cell cycle progression, including cyclin-dependent kinase 4 and cyclin D1, and increased the expression of proteins that inhibit cell cycle progression, including p27. Furthermore, flow cytometry analysis showed that TSL-1 induced H661 cell apoptosis. Western blot analysis showed that TSL-1 reduced the expression of the anti-apoptotic protein B-cell lymphoma 2, and degraded the DNA repair protein, poly(ADP-ribose) polymerase. TSL-1 shows potential as a novel therapeutic agent or for use as an adjuvant for treating human lung large cell carcinoma.

Terminal and progenitor lineage-survival oncogenes as cancer markers

Tumour classification has traditionally focused on differentiation and cellular morphology, and latterly on the application of genomic approaches. By combining chromatin immunoprecipitation with expression array, it has been possible to identify direct gene targets for transcription factors for nuclear hormone receptors. At the same time, there have been great strides in deriving stem and progenitor cells from tissues. It is therefore timely to propose that pairing the isolation of these cell subpopulations from tissues and tumours with these genomics approaches will reveal conserved gene targets for transcription factors. By focusing on transcription factors (lineage-survival oncogenes) with roles in both organogenesis and tumourigenesis at multiple organ sites, we suggest that this comparative genomics approach will enable developmental biology to be used more fully in relation to understanding tumour progression and will reveal new cancer markers. We focus here on neurogenesis and neuroendocrine differentiation in tumours.