Prognostic impact of the Controlling Nutritional Status score in patients with non-small cell lung cancer treated with pembrolizumab

Background: Pembrolizumab, an anti-programmed cell death-1 (PD-1) monoclonal antibody, has been shown to yield a durable response and significant survival benefit in some non-small cell lung cancer (NSCLC) patients. Recent studies have shown that the Controlling Nutritional Status (CONUT) score, a novel nutritional index, can be useful for predicting the prognosis in some malignancies. However, its usefulness in predicting the clinical outcome of immune-checkpoint inhibitor (ICI) treatment in patients with NSCLC has not been clarified. The aim of this study was to investigate the clinical significance of the CONUT score in NSCLC patients treated with pembrolizumab.

Methods: We conducted a retrospective analysis of the clinical data of 32 patients with advanced NSCLC who received pembrolizumab monotherapy. A cut-off CONUT score of 2 was used to categorize patients into low and high CONUT groups. We evaluated the relation between the clinicopathological factors including CONUT score and neutrophil-to-lymphocyte ratio (NLR) and the prognosis.

Results: Twenty-two patients were classified into the low CONUT score group, while 10 were classified into the high CONUT score group. In the univariate and multivariate analyses, the number of prior treatments and the CONUT score were found to independently predict progression-free survival (PFS) (P<0.05), while the CONUT score as well as NLR was an independent prognostic factor for overall survival (P<0.05). In addition, in patients who received pembrolizumab as a first-line treatment, a high CONUT score was associated with a significantly worse PFS and overall survival in comparison to a low CONUT score.

Conclusions: The CONUT score has potential application as a predictor of the therapeutic effect and the prognosis of NSCLC patients treated with pembrolizumab. Our findings suggest that in addition to the programmed cell death ligand 1 expression level, the CONUT may also be a useful indicator for selecting NSCLC patients who may benefit from ICI treatment.