Neuroendokrine Tumoren der Lunge: State of the Art

Neuroendocrine neoplasms (NEN) account for around a fifth of all lung malignancies, with small cell lung cancer (SCLC) being the most common of them. The well-differentiated neuroendocrine tumors (NET) of the lung (also known as lung carcinoids), on the other hand, are rare. The prognosis is generally favorable, with 10-year survival rates of around 60% for typical carcinoids (NET G1) and 20% for atypical carcinoids (NET G2) in the metastatic stage. Clinically, NETs of the lung can—albeit rarely—exhibit hormonal syndromes (e.g., carcinoid syndrome or Cushing’s syndrome). Interestingly, these tumors have a low mutation rate, with epigenetic-related genes being the most frequently mutated. Treatment strategies for NET of the lung include surgical resection (as a potentially curative intervention in the localized stage), a wait-and-see approach in selected cases, and systemic therapy options. Everolimus is the only approved systemic therapy and led to a prolongation of progression-free survival (PFS) in the placebo-controlled pivotal study (median PFS 9.2 months for everolimus versus 3.6 months for placebo). Despite lack of formal approval, somatostatin analogs are another therapy recommended by various guidelines and can be used (like peptide receptor radionuclide therapy) if somatostatin receptors are present. Further systemic treatment options are mainly chemotherapies, such as temozolomide- or oxaliplatin-based combinations, while immunotherapy or molecular matched-treatment strategies have not yet shown any relevant effects.