The Impact of Tumor Size on Node Involvement in Typical Lung Carcinoids.

Background: Observation has been suggested as an alternative to surgical resection for small typical lung carcinoids. We sought to evaluate the potential impact of tumor growth and lymphatic spread during observation by examining predictors of node positivity and the impact of tumor size and node status on survival.

Methods: National Cancer Database cases of typical lung carcinoid resections from 2006 to 2016 were analyzed. Predictors of lymph node involvement and survival were determined.

Results: Overall, 1019 of 8257 patients who underwent typical carcinoid resection had at least 1 positive node (12.3%). The incidence of node positivity among the 921 patients with subcentimeter tumors was 5.4% (n = 50). Increasing tumor size was independently associated with nodal involvement. Patients with nodal involvement had significantly worse 5-year survival (89.5% vs 94.0%; < .001). Increasing tumor size was not associated with worse survival in multivariable analysis, but node positivity did independently predict worse survival.

Conclusions: More than 5% of patients with subcentimeter typical carcinoids of the lung have nodal metastases, and node involvement is an independent predictor of worse survival, whereas tumor size is not. These data suggest that even patients with small tumors should generally undergo resection when diagnosed.