Prognostic value of distant organ-specific metastases in newly diagnosed lung neuroendocrine tumours

Lung neuroendocrine tumours are rare neoplasms with poor outcomes for patients with distant metastases. Nonetheless, the prognostic value of metastatic sites remains unclear. Wen et al. used the SEER database to fill this knowledge gap [5]. They extracted data on clinical-pathological characteristics, specific metastatic sites, and outcomes of stage 4 lung neuroendocrine tumours from the SEER database from 2010 to 2014. Estimates of OS and lung cancer-specific survival were based on the Kaplan-Meier method. Comparisons were developed using log-rank tests and Cox regression models.

The study included 12,337 patients with stage 4 neuroendocrine tumours. The 5-year OS was 10.7%; it was 18.3% for lung cancer-specific survival. At diagnosis, 2,159 patients had specific organ metastases to the liver, lungs, bone, or brain. The liver was the most common metastatic site (n=1,183 patients; 50.6%), followed by bone (n=801; 34.3%), lung (n=701; 29.9%), and brain (n=616; 26.4%). Patients with contralateral lung metastases had significantly better outcomes compared to other patterns of metastasis. OS at 1 year was 63.2%; at year 5, it was 43.2%. One-year lung cancer-specific survival was 74.0%; the 5-year rate was 62.9% (P<0.001). Those with any brain metastases had the most unfavourable outcomes. One-year OS was 20.3%; at 5 years, the rate dropped to 2.1% (P<0.001). One-year lung cancer-specific survival was 26.0%; the 5-year rate was 7.7% (P<0.001).

Multivariate regression on OS and lung cancer-specific survival showed that age >60, male sex, poorer differentiation, and brain metastases (all P<0.001) were independent predictors of poor prognoses. Data indicated a nearly twentyfold difference in 5-year survival between patients with isolated lung and brain metastases.