A novel prognostic marker in patients with non-small cell lung cancer: musculo-immuno-nutritional score calculated by controlling nutritional status and creatine kinase

Abstract

Background: Controlling nutritional status (CONUT) and skeletal muscle area (SMA) are both useful prognostic factors in patients with non-small cell lung cancer (NSCLC). We hypothesized that low serum creatine kinase (CK) would be a surrogate of decreased SMA, and defined a novel prognostic factor, CONUT/CK score (CNKS). The aim of this study was to elucidate the clinical significance of CNKS in NSCLC patients.

Methods: One hundred and eighty-nine patients who underwent surgical resection of NSCLC and whose preoperative computed tomography images were available were enrolled. The CNKS was calculated by summing CONUT score and CK score, which was defined as 0 if the CK concentration is within normal range, and 2 if it is under lower limit. The optimal cut-off values of CNKS and CONUT score were 4 and 2, respectively.

Results: Low CK was significantly associated with decreased SMA (P=0.012). The high CNKS group was significantly associated with men and smoking history (P=0.006 and P=0.015, respectively). The high CNKS group had significantly shorter overall survival (OS) and disease-free survival (DFS) (P<0.001 and P=0.003, respectively) than the low CNKS group. The CNKS was found to be an independent prognostic factor for OS and DFS (P=0.012 and P=0.017, respectively), while CONUT score was not. The CNKS was a novel significant predictor of a poor prognosis in patients with NSCLC.

Conclusions: The nutritional status combined with skeletal muscle index was suggested to provide more useful prognostic information than alone, which should be investigated in further prospective studies with a larger cohort.

Keywords: Controlling nutritional status (CONUT); creatine kinase (CK); non-small cell lung cancer (NSCLC).

Figure 1

Imaging and assessment of skeletal muscle area in patients with non-small cell lung cancer. (A) An example of the paravertebral muscle area at the level of the 12th thoracic vertebra (cm²); (B) the association between serum creatine kinase status (normal/under lower limit) and standardized paravertebral muscle area at the level of the 12th thoracic vertebra (cm²/m²).

Figure 2

The relationships between controlling nutritional status/creatine kinase score and (A) men, (B) smoker, and (C) higher pack-year are shown using graphs.

Figure 3

Kaplan-Meier curves for disease-free survival according to the (A) controlling nutritional status (CONUT)/creatine kinase score (CNKS) and (B) CONUT score. Kaplan-Meier curves for overall survival according to the (C) CNKS and (D) CONUT score.

Figure S1

The receiver operating characteristic curves of (A) controlling nutritional status (CONUT)/creatine kinase score (CNKS) and (B) CONUT score for 5-year survival are shown. The areas under the curve of CNKS and CONUT score were calculated as 0.637 and 0.598, respectively.