BackgroundThe immunological status, consisting of “inflammation status” and “nutritional condition,” is important for the survival of patients with various cancers, including non-small cell lung cancer (NSCLC). The neutrophil/lymphocyte ratio (NLR) reflects the inflammation status, and the prognostic nutritional index (PNI) reflects the immunological nutritional condition. In the present study, the correlation between the NLR and the PNI as well as the consistency and magnitude of the prognostic impact of the NLR and the PNI were investigated.MethodsWe conducted a retrospective review of data from 334 patients who had undergone a curative resection for NSCLC. The NLR and the PNI were calculated, which was routinely performed before surgery. The correlations between the NLR and the PNI and survival were then evaluated.ResultsA clear inverse correlation was observed between the NLR and the PNI. The NLR was associated with sex, smoking history, the CEA level, tumor size, and vascular invasion. The PNI was associated with sex, age, smoking history, tumor size, histological type, tumor differentiation, and vascular invasion. Patients with NLR ≥2.5 had a significantly poorer survival outcome, and patients with PNI <50 had a significantly poorer survival outcome. A multivariate analysis demonstrated that age, nodal metastasis, tumor differentiation, NLR, and PNI were independent predictors of disease-free and overall survival.ConclusionsOur study demonstrated a significant inverse correlation between the NLR and the PNI, and a high NLR and a low PNI were significantly associated with a poor survival among patients who had undergone a complete resection for NSCLC.

Immunocheckpoint inhibitors targeting the programmed cell death-1 (PD-1) and PD-1 ligand 1 (PD-L1) axis have shown promising results in patients with non-small-cell lung cancer (NSCLC). Recent research has shown that epidermal growth factor receptor (EGFR) signaling affects PD-L1 expression in NSCLC cells; however, the mechanism regulating PD-L1 expression in tumor cells remains unclear. Using immunohistochemistry, we evaluated the impact of expression of PD-L1 and EGF family receptors EGFR and human epidermal growth factor receptor 2 (HER2) in tumor cells from 91 patients with pathological Stage IA-IIIA NSCLC. Overexpression of PD-L1 was observed in 14% of the resected tumors, and associated with poor recurrence-free survival (p = 0.021) and overall survival (p = 0.033). PD-L1 expression is positively correlated with EGFR expression and inversely correlated with HER2. NSCLC cell lines were treated in vitro with the EGFR ligand EGF with or without inhibition of EGFR or HER2, after which PD-L1 expression was evaluated using flow cytometry. Consistent with previous reports, PD-L1 expression was clearly enhanced by EGF. EGFR-tyrosine kinase inhibitors or EGFR small interfering RNA (siRNA) blocked EGF-induced PD-L1 overexpression in NSCLC cell lines, but HER2 siRNA did not. Moreover, our findings suggest that PD-L1 expression could be partially regulated via the PI3K/AKT and JAK/STAT pathways. We conclude that PD-L1 overexpression is associated with poor prognosis and is positively correlated with EGFR expression but inversely correlated with HER2 expression in NSCLC. We also showed that EGFR and HER2 have different effects on EGF-induced PD-L1 expression in NSCLC cell lines.

MHC class I chain-related molecule A and B (MICA/B) are NK group 2 member D (NKG2D) ligands, which are broadly expressed in transformed cells. Both DNA damage-induced ataxia-telangiectasia-mutated (ATM)- and ATM and Rad3-related protein kinases (ATM-ATR) signaling and oncogene-induced PI3K-AKT signaling regulate the expression of NKG2D ligands, which promote NK cell-mediated cytotoxicity via NKG2D-NKG2D ligand interactions. NKG2D ligand overexpression was recently reported to be correlated with good prognosis in several types of cancer. However, the prognostic significance of NKG2D ligands in non-small cell lung cancer (NSCLC) remains unclear. Here, MICA/B expression was evaluated based on immunohistochemistry of 91 NSCLC samples from patients following radical surgery. In addition, expression of MICA/B was assessed in NSCLC cell lines treated with cisplatin in order to evaluate the regulatory mechanisms of MICA/B expression. Overall, 28 out of 91 (30.8%) specimens showed high expression level of MICA/B, which was associated with low (18)F-fluorodeoxyglucose uptake and manifestation of adenocarcinoma. After a median follow-up of 48.2 months, high MICA/B expression was associated with good recurrence-free survival (p = 0.037). In vitro assays using cell lines revealed that MICA/B expression was upregulated by cisplatin via ATM-ATR signaling, resulting in enhanced NK cell-mediated cytotoxicity. Upregulated MICA/B expressions in patients with radically resected NSCLC are predictive of good disease prognosis. Cisplatin-induced MICA/B upregulation is possibly an indirect mechanism by which the innate immune system eliminates tumor cells. NKG2D-NKG2D ligand-targeting therapy is a promising avenue for future immune-chemotherapy development.

The prognosis of patients with NSCLC recurrence after surgery is currently improving. Our results suggested two new prognostic factors, adjuvant chemotherapy and EGFR mutations, neither of which have been previously reported. Treatment strategies for postoperative recurrence should be established based on a more detailed subdivision of factors, such as histology and molecular markers, in the future.