Histological Grade: Analysis of Prognosis of Non-small Cell Lung Cancer After Complete Resection.

Background/aim: Although the 2015 World Health Organization Classification reported that histological grading may be helpful in lung cancer management, a widely accepted histological grading system with clearly defined criteria and demonstrable clinical significance has not been developed. We investigated the prognoses of patients with resected non-small cell lung cancer (NSCLC) to identify prognostic factors, especially histological grade.

Materials And Methods: The medical records of 531 patients between 2010 and 2015 were retrospectively reviewed. Overall survival (OS) curve was plotted using the Kaplan-Meier method. Cox regression analyses were used to evaluate the hazard ratio (HR) with endpoint of OS.

Results: The 5-year OS rate in groups with histological grade 1, grade 2, and grade 3+4 groups was 95.8%, 85.7%, and 72.1%, respectively (p<0.001). Multivariate analysis identified histological grade and vascular invasion as independent predictors of OS [histological grade: HR=1.533, p=0.002].

Conclusion: Histological grade was an independent prognostic factor of patients resected for all stages of NSCLC.