ABSTRACT
The objective of the present study was to characterize the difference in 10-year carcinoid-specific survival (CSS) and disease-free survival (DFS) among patients with resected pulmonary typical carcinoid (TC) and atypical carcinoid (AC). Patients diagnosed with pulmonary carcinoid tumors (PCT) between January 1, 1997, and December 31, 2016, were identified. All patients underwent video-assisted thoracoscopic surgery or thoracotomy with thoracic lymphadenectomy. Cumulative CSS was estimated using the Kaplan-Meier model. The analysis of hazard ratios (HRs) and 95% confidence intervals (CIs) was performed using univariate and multivariate Cox proportional hazards models. A total of 404 patients with PCT were included in the present study. The 10-year CSS and DFS rates of patients with AC were significantly worse than those of patients with TC (49.1 vs. 86.8% and 52.2 vs. 92.6%, respectively; P<0.001). In the CSS multivariate analysis, older age and lymph node involvement (HR, 2.45; P=0.022) were associated with worse survival in AC, while age, male sex, M1 stage, cigarette smoking and inadequate N2 lymphadenectomy were associate with worse survival in TC. In the recurrence multivariate analysis, N1-3 stage (HR, 2.62; 95% CI, 1.16-5.95; P=0.018) and inadequate N2 lymphadenectomy (HR, 2.13; 95% CI, 1.04-4.39; P=0.041) were associated with an increase in recurrence in AC, while male sex (HR, 3.72; 95% CI, 1.33-10.42; P=0.010) and M1 stage (HR, 14.93; 95% CI, 4.77-46.77; P<0.001) were associated with an increase in recurrence in TC. In conclusion, patients with AC tumors had significantly worse CSS and DFS rates compared with patients with TC. The degree of nodal involvement in AC was a prognostic marker, in contrast to that in TC. Inadequate lymphadenectomy increased the risk of recurrence in AC and mortality in TC, although surgical approaches did not have a significant impact. The present study therefore emphasizes the importance of mediastinal nodal dissection in patients with PCTs.
ABSTRACT
AIMS: Members of the growth factor family of neurotrophins [NTs; e.g. brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT3)] and their high-affinity receptors (tropomyosin-related kinase; Trk) and low-affinity receptors p75 neurotrophin receptor (p75NTR) have been localized to pulmonary artery (PA) in humans. However, their role is unclear. Based on previous findings of NTs and their receptors within the pulmonary endothelium, we tested the hypothesis that NTs induce nitric oxide (NO) production in pulmonary endothelial cells (ECs), thus contributing to vasodilation. METHODS AND RESULTS: In human pulmonary artery ECs loaded with the NO-sensitive fluorescent dye diaminofluorescein-2, both BDNF and NT3 (100 pM, 1 nM, and 10 nM) acutely (<10 min) and substantially increased fluorescence levels in a concentration-dependent fashion (to levels comparable to that induced by 1 µM acetylcholine). NT-induced elevation of NO levels was blunted by the tyrosine kinase inhibitor K252a, the nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester, the Ca(2+) chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, and the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. Suppression of TrkB or TrkC expression via siRNA as well as functional blockade of p75NTR prevented NT-induced NO elevation. Both BDNF and NT3 increased phosphorylation of Akt and endothelial NO synthase (eNOS). In endothelium-intact porcine PA rings, NTs increased cGMP and induced vasodilation in pre-contracted arteries. CONCLUSION: These results indicate that NTs acutely modulate pulmonary endothelial NO production and contribute to relaxation of the pulmonary vasculature.
