• Tumore neuroendocrino del polmone
• PRRT
• analoghi della somatostaina

Aim: Thyroid transcription factor-1 (TTF-1), a nuclear transcription protein selectively expressed in the thyroid, the diencephalon and respiratory epithelium, is expressed in more than 90% of pulmonary small cells carcinomas (SCLSs) and in almost 75% of pulmonary non-small cell carcinomas (NSCLSs) but it is absent in typical pulmonary carcinoids (TCs).
Neuroendocrine tumors (NETs) overexpress somatostatin receptors (SSTR). SSTR overexpression is the basis for the use of radiolabelled somatostatin analogues in diagnosis and treatment of NETs. Peptide receptor radionuclide therapy (PRRT) with 177Lu-labelled peptides has been used in the treatment of NETs.
In this study we evaluated the role of TTF-1 in predictive response and progression free survival (PFS) after 177Lu-Dotatate treatment in patients with advanced bronchopulmonary NETs.
Methods: We retrospectively evaluated 36 patients with advanced bronchopulmonary NETs overexpressing SSTR and treated with 177Lu-Dotatate with a cumulative activity up to 27,7GBq. On the basis of the TTF-1, 17 patients were TTF-1 positive while 19 patients resulted TTF-1 negative.
Results: After the treatment, 15 of the 19 TTF-1 negative patients showed disease control (DC, i.e. complete response + partial response + stable disease), while the other 4 patients evolved to progressive disease (PD). The effect of the treatment has been different on the 17 TTF-1 positive patients: only two of them showed DC and the other 15 patients evolved to PD. There is a direct correlation between treatment response and the expression of TTF-1 (Pearson’s chi-square <0,15). PFS index for TTF-1 negative patients is 23 months, while for TTF-1 positive patients it is only 8 months.
Conclusions: These results suggest that positivity to TTF-1 causes a negative predictive response to Lu-PRRT in patients with advanced bronchopulmonary NETs. Prognosis for patients expressing TTF-1 is negative.