Examined lymph node count linked to better survival in typical carcinoid tumours

In patients with early-stage typical carcinoid tumours (TC), long-term survival rate increases with higher examined lymph nodes (ELNs), suggests a study.

The authors evaluated the prognostic impact of the number of ELNs in resected early-stage pulmonary TC. They identified patients who underwent sublobar resection and lobectomy for stage T1N0M0 TC between 2004 and 2016 from the Surveillance, Epidemiology, and End Results database. Patients were then enrolled in the ELNs ≥4 or ELNs <4 groups (optimal cutoff using X-tile).

Propensity score matching was applied to balance baseline intergroup characteristics. The authors then calculated and compared overall survival (OS) rates using Kaplan‒Meier curve and log-rank test. Finally, they identified independent prognostic factors using Cox proportional hazard model analysis.

A total of 2,234 participants were included, of which 961 (43.02 percent) had ELNs <4 and 1,273 (56.98 percent) had ELNs ≥4. Patients in the ELNs ≥4 group had significantly higher OS at 5 years compared to those in the ELNs <4 group both before and after propensity score matching (before: 95.41 percent vs 89.71 percent; p<0.001; after: 95.24 percent vs 90.28 percent; p=0.004).

This survival trend in the lobectomy and sublobar resection groups was confirmed in surgical subgroup analysis. In tumour size-based subgroup analysis, OS was higher with ELNs ≥4 than with ELNs <4 for tumours measuring 1.1‒3.0 cm, but not for those measuring <1.0 cm. Finally, multivariate analysis revealed that ELNs ≥4 correlated with better OS.

“Therefore, we recommend at least four ELNs as the cutoff value for evaluating the prognosis of early‑stage TCs, especially for patients with a tumour size of 1.1 to 3.0 cm,” the authors said.