Role of Bone Metastases in Lung Neuroendocrine Neoplasms: Clinical Presentation, Treatment and Impact on Prognosis

Lung neuroendocrine neoplasms (L-NEN) are heterogeneous tumors. While bone metastases (BM) have been associated with worse prognosis in other NEN, their role in L-NEN deserves in-depth analysis. This study analyzes the clinical presentation, treatment and survival outcomes of L-NEN, focusing on patients with BM compared with patients without metastases or with metastases in other sites (OtherMtx). The clinicopathological and survival data of L-NEN admitted to the Federico II University were retrospectively evaluated. Fifty L-NEN were included. Among 27 metastatic patients (54%), 13 (26%) had BM, more commonly occurring in males than females and in primary bilateral L-NEN or L-NEN > 26 mm, with higher Ki67. Atypical carcinoid and hypovitaminosis D were associated with BM. The number of metastatic sites was higher in patients with BM than OtherMtx. Synchronous metastases were associated with shorter overall survival (OS). The median progression-free survival (PFS) and OS in patients with BM were similar to OtherMtx, but a two-times increased risk of shorter OS was detected. BM do not impact PFS or OS more than OtherMtx, but the increased risk of shorter OS in patients with BM should be considered. Periodic bone evaluation in L-NEN should be recommended.