The Significance of Controlling Nutritional Status (CONUT) Score as a Novel Prognostic Parameter in Small Cell Lung Cancer

Purpose The immuno-nutritional status is closely related to the prognosis in many cancers. Controlling nutritional status (CONUT) score is a new parameter that reflects the immuno-nutritional status and is prognostic in some cancers. However, the prognostic significance of the CONUT score in small cell lung cancer (SCLC) is unknown. We aimed to demonstrate the prognostic significance of the CONUT score in patients with SCLC. Methods Two hundred sixteen patients who were followed up with SCLC were included in the study retrospectively. According to the receiver operating characteristic (ROC) curve analysis, the optimal cutoff values were determined for the CONUT score, and the patients were divided into low (< 2) and high (>= 2) CONUT groups. Neutrophil-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and prognostic nutritional index (PNI) were grouped based on a cutoff point 2.84, 626, and 46.1, respectively. Cox regression analyses were used to assess their prognostic values for progression-free survival (PFS) and overall survival (OS). Results The high CONUT group had significantly worse PFS and OS than the low CONUT group (p < 0.001, p < 0.001). In univariate analysis, stage, prophylactic cranial irradiation, extrapulmonary lesion, PNI, body mass index, CONUT score were found to be significant for both PFS and OS. In multivariate analysis, only CONUT score and stage were found as independent prognostic factors for both PFS (p: 0.018, p: 0.046) and OS (p: 0.038, p: 0.006). Conclusion The CONUT score at the time of diagnosis is an independent prognostic parameter that predicts recurrence and survival times in SCLC.