Systemic therapy for pulmonary carcinoids.

Between 25 and 33% of neuroendocrine tumours arise in the lung as low-grade typical pulmonary carcinoids (TPC), intermediate-grade atypical pulmonary carcinoids (APC), and high-grade large cell neuroendocrine or small cell carcinomas. The relatively uncommon incidence and prevalence of PCs are progressively increasing. However, data regarding systemic treatment for PCs are limited, controversial and based on old reports with few randomized or placebo-controlled trials, small sample sizes, or including tumours with very different behaviours. Moreover, conclusions are generally extrapolated from the outcome of extra-pulmonary carcinoids, treatment arms are not well defined or mix different therapies, and the indolent nature of some PCs is not adequately considered in designing control arms. Here, we reviewed and discuss current recommendations regarding systemic treatments for PCs.