The Relationship between Sarcopenia and Systemic Inflammatory Response for Cancer Cachexia in Small Cell Lung Cancer

Background The prognostic significance of sarcopenia, an important component of cancer cachexia, has been demonstrated in oncologic patients. Catabolic drivers have been suggested to be key features of cancer cachexia. Objective To determine the relationship between systemic inflammatory markers and CT-determined muscle mass in patients with SCLC. Methods Cross-sectional muscle areas were evaluated at the level of the third lumbar vertebra (L3) using baseline CT images in 186 SCLC patients. Sarcopenia was defined as a L3 muscle index (L3MI, muscle area at L3/height(2)) of < 55 cm(2)/m(2) for men and of < 39 cm(2)/m(2) for women. Systemic inflammatory markers investigated included serum white blood cell count (WBC), neutrophil: lymphocyte ratio (NLR), C-reactive protein (CRP), and albumin. Results Mean L3MI was 47.9 +/- 9.7 cm(2)/m(2) for men and 41.6 +/- 7.0 cm(2)/m(2) for women. Sarcopenia was present in 128 patients (68.8%), and sarcopenic patients had significant serum lymphocyte counts and albumin levels (p = 0.002 and 0.041, respectively), and higher NLRs and CRP levels (p = 0.011 and 0.026) than non-sarcopenic patients. Multivariable analysis revealed that CRP independently predicted L3MI (beta = -0.208; 95% CI, -0.415 to -0.002; p = 0.048), along with gender and BMI (p values < 0.001) and performance status (p = 0.010). Conclusion The present study confirms a significant linear relationship exists between CT-determined muscle mass and CRP in SCLC patients. This association might provide a better understanding of the mechanism of cancer cachexia.