Prognostic and diagnostic markers in neuroendocrine thymic tumours:a pilot study

Background: Thymic neuroendocrine neoplasm (TNENs) are rare and aggressive cancers. The aim of the present study was to examine the prognostic significance of a panel of twenty biomolecular markers and to select the most common ones in order to better understand the pathogenesis and the prognostic factors of TNENs. Material and methods: Clinical data and pathological tissue samples collected from surgically treated patients affected by TNENs were analysed. Twenty biomolecular markers, adopted in previously worldwide published papers, were utilized in a tissue microarray parallel in situ analyses. All patients were divided into three groups according to histological diagnosis: typical carcinoid(TC), atypical carcinoid(AC), and mixed (MxTNET). Overall and disease-free survival analysis was performed with the Kaplan-Meier method and the log-rank test. Results: A total of 20 patients (1994-2012) was outlined from the databases.The great majority were male (90%) with a mean age of 55 years (IQR 35-82). 5- and 10- year OS of the cohort were 65% and 47%. 5-and 10-year DFS were 27% and 18%. Analysing the 20 markers, different expression between different histological types of TNETs was noticed with a significant trend in the DFS, towards two molecules such as Osteopontin (p=0.032) and PTEN (p=0.023). Analysing the overall survival, significant differences were noticed for pMTor (p=0.004). This protein had also an impact on DFS (p=0.002). Conclusion: According to the reported data, our analysis confirms the importance of OPN and PTEN also in neuroendocrine thymic tumours. Those parameters may be studied in larger cohort and integrated with the already known prognosticators to better define their impact on long term outcomes. Large multicentre studies are mandatory to define a scoring system able to predict the recurrence after radical surgery and define who benefit the most from aggressive therapies