Characterization, Prognosis, and Treatment of Patients With Metastatic Lung Carcinoid Tumors

Introduction: Metastatic lung carcinoids (MLCs) remain poorly characterized and no prognostic stratification exists.

Methods: We conducted a retrospective study including patients with MLCs in two European expert centers. The aims were to characterize these cases and to identify prognostic factors of survival and effectiveness of their treatments.

Results: A total of 162 patients with MLC were included: 50% were women, and the median age was 61 years. Half of the patients had synchronous metastases, mainly located in the liver (75%), bone (42%), and lung (25%). According to WHO classification, MLCs were typical (28%), atypical (60%), or unspecified (12%). A functioning syndrome was observed in 43% of cases and an uptake at somatostatin receptor scintigraphy in 76% of cases. The 5-year overall survival rate was 60% and at 10 years this was 25%. In multivariate analysis, Eastern Cooperative Oncology Group performance status of 0-1 (hazard ratio [HR]: 5.81, 95% confidence interval [CI]: 2.10-16.11), uptake on SRS (HR: 0.38, 95% CI: 0.22-0.66), low serum chromogranin A (HR: 2.27, 95% CI: 1.36-3.81), and typical carcinoid (HR: 1.87, 95% CI: 1.26-2.78) were associated with better survival. According to Response Evaluation Criteria in Solid Tumors version 1.0, the highest objective response rates were obtained after radiofrequency ablation of metastases (86%), liver embolization (56%), peptide receptor radionuclide therapy (27%), and oxaliplatin-based chemotherapy (18%).

Conclusions: MLCs are characterized by a high frequency of atypical carcinoids, functioning syndrome, and liver/bone metastases. WHO classification, performance status, somatostatin receptor scintigraphy, and chromogranin A were associated with longer survival. Partial response was more frequent with locoregional therapies, peptide receptor radionuclide therapy, or oxaliplatin-based chemotherapy.