Co-expression of NF-κB-p65 and phosphorylated NF-κB-p105 is associated with poor prognosis in surgically resectable non-small cell lung cancer.

Nuclear factor-kappa B (NF-κB) as a prognostic marker remains unclear in non-small cell lung cancer (NSCLC). Here, we studied NF-κB-p65 (p65) expression and phosphorylated NF-κB-p105 (p-p105) expression in NSCLC and correlated the finding with overall survival (OS) and clinicopathological features. A total of 186 archival samples from patients with surgically resectable NSCLC were probed with p65 and p-p105 (Ser 932). The p65-positive expression and p-p105-positive expression were defined as distinct nuclear p65 and cytoplasmic p-p105 labelling in at least 1% of tumour cells, respectively. The positive staining of p65 alone, p-p105 alone and co-expression of p65 and p-p105 were observed in 61 (32.8%), 90 (48.4%) and 35 (18.8%) patients, respectively. Co-expression of p65 and p-p105 but not of either p65 or p-p105 alone was associated with a poor prognosis. Patients with co-expression of p65 and p-p105 had a shorter OS than others, median OS 26.5 months versus 64.1 months, HR 1.85 (95% CI: 1.18-2.91), P = 0.007. There was no statistically significant association between clinicopathological characteristics and either p65 or p-p105 alone or co-expression of p65 and p-p105. This indicates that co-expression of p65 and p-p105 was a poor prognostic factor, and pathologic studies of NF-κB expression could include multiple pathway components in NSCLC.