Lung neuroendocrine tumors: grade and recurrence rate after surgery

Lung neuroendocrine tumors (NETs) are a rare and heterogeneous group of neoplasms. They are classified into low-grade (typical carcinoid), intermediate-grade (atypical carcinoid), and high-grade (large-cell and small-cell neuroendocrine carcinoma) tumors. While surgical resection remains the mainstay treatment for many NETs, recurrence rates differ substantially among subtypes. Our primary outcome is to analyze the association between histologic subtype of lung NETs and tumor recurrence.

A comparative retrospective study with a prospective case registry was conducted. All adult patients who underwent surgery due to lung NETs from January 2015 to December 2024 in a high-volume center were included. Demographic, perioperative and histopathological variables were analyzed. Tumor recurrence rate was compared between patients who presented with carcinoid tumors and those who presented with large-cell neuroendocrine carcinoma.

A total of 57 patients were included (48 with carcinoid tumors and 9 with large-cell neuroendocrine carcinoma). Recurrence occurred in 33.3% of large-cell neuroendocrine carcinoma cases versus 4.1% in the carcinoid group (p 0.02). Large-cell neuroendocrine tumors also showed significantly larger tumor size (p 0.02), higher Ki-67 index (p 0.001) and more nodal involvement (p 0.04).

Lung NETs exhibit distinct recurrence rates based on histologic grade. High-grade tumors present more aggressive features and a higher risk of recurrence. A multidisciplinary approach and strict long-term follow-up are essential, especially in highgrade lung NETs.