Materials and Methods: Patients with stage IIB NSCLC who underwent surgery in our hospital between January 2006 and December 2015 were included in the study. The patients were evaluated in two groups: T3N0 patients staged as IIB due to pN0 (Group A) and T1N1/T2N1 patients (Group B).

Results: Of the 192 patients were included in the study. There were 47 patients in group A (24.5%) and 145 patients in group B (75.5%). 5-year survival rates was 58.2%. There was no statistically significant difference in survival according to T stage. The 5-year survival rates in the T1, T2, and T3 groups were 69%, 55.3%, and 54.6%, respectively (p = 0.34). The main prognostic factors affecting survival were advanced age (p = 0.02). The mean DFS was 72 months and the 5-year DFS rate was 54%. Advanced age and male sex, were identified as poor prognostic factors for DFS (p < 0.005).

Conclusions: The stage IIB category remains heterogeneous despite the updated eighth edition IASCL staging system. The results of our study indicate that age was the main prognostic factors affecting survival in stage IIB NSCLC. However, the effect of visceral pleural invasion and lymph node involvement on survival in stage IIB subgroups was not detected, more comprehensive multicenter studies are still needed. Keywords : lung cancer, stage IIb, survival, prognostic factors, pleural invasion