High grade tumor budding is associated with poor survival in pathologic stage I lung adenocarcinoma

Abstract

Aim: Tumor budding is a significant prognostic parameter that has been related to aggressive behavior in early-stage tumors of various origins. The aim of this study was to evaluate the clinicopathological significance of tumor budding in pathologic stage (pStage) I lung adenocarcinomas.

Methods: This study comprised 107 patients who underwent curative resection for pStage I lung adenocarcinomas at our hospital between December 2010 and January 2016. We examined tumor budding on routine hematoxylin and eosin (H&E) slides from resected specimens. Tumors were categorized into two groups based on the degree of tumor budding: low grade (grade 0-1) and high grade (grade 2-3). We evaluated the relationship between tumor budding and overall survival (OS), disease-free survival (DFS) and clinicopathological parameters.

Results: There is a significant difference (p = 0.002) between the 5-year DFS rates of the high-grade and the low-grade tumor budding group, which were 70 % and 90 %, respectively. High-grade tumor budding positive patients from the same pathological stage (p < 0.001; HR = 2.93 [1.51-5.68]) and clinical stage (p = 0.002) had poorer cumulative survival rates than low grade tumor budding positive patients. High grade tumor budding was positively associated with spread through air spaces (STAS) (p < 0 0.001), lymphovascular invasion (LVI) (p < 0.001), tumor necrosis (p < 0.001), high SUVmax value (SUVmax>3.0) (p < 0.001), and tumor size >20 mm (p = 0.024). High-grade tumor budding was significant prognostic factor of OS (p < 0.006) and DFS (p < 0.001) on univariate Cox regression hazard model analysis. However, it did not show significance in the multivariate analysis (p > 0.05).

Conclusions: High-grade tumor budding is an independent prognostic factor and associated with adverse clinicopathological features and poor survival rates. We proposed that high-grade tumor budding should be recognized as a new prognostic parameter and will be beneficial in predicting the clinical course in pStage I lung adenocarcinomas.

Keywords: Lung adenocarcinoma; Prognosis; Tumor budding.