Introduction Cancer cachexia affects many advanced non-small-cell lung cancer (NSCLC) patients. Cachexia index (CXI) was developed to assess the degree of cachexia in these patients. Methods Patients with metastatic NSCLC diagnosed between January 1, 2000, and June 30, 2011, at our institution were retrospectively studied. Abdominal computed tomography scans done within 1 month of diagnosis were reviewed to estimate skeletal muscle area (SMA) and skeletal muscle index (SMI) at the L3 level. CXI was developed as follows: [Formula: see text] where SMI is the skeletal muscle index, Alb is the serum albumin, and NLR is the NLR neutrophil-to-lymphocyte ratio. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Survival among various factors was calculated using the log-rank test. Multivariate Cox regression was used to perform survival analysis in order to estimate the effects of various factors. Results Patients were divided into two groups around the median into stage I cachexia (CXI ≥35, n = 56) and stage II cachexia (CXI <35, n = 56). Groups did not differ in age, gender, ethnicity, or histology of cancer. Patients with stage II cachexia had significantly worse PFS (2.45 vs 5.43 months, P < 0.0001) and OS (3.45 vs 8.8 months, P = 0.0001) than those with stage I cachexia. On multivariate analysis adjusting for gender, race, and histology, patients with stage II cachexia were found to have worse PFS (hazard ratio [HR] 1.94, 95% confidence interval [CI] 1.27–2.95) and OS (HR 1.53, 95% CI 1.0009–2.34). Conclusion The CXI is a novel index for estimating cachexia that also correlates with prognosis in both men and women with advanced NSCLC.
L3 skeletal muscle index (L3SMI) is a surrogate marker of sarcopenia and frailty in non-small cell lung cancer patients
