Sarcopenia is a predictive marker for response to erlotinib in patients with lung adenocancer

Background: Adenocancer pathologic subtype, smoking history, and women gender have been known to predict the parameters such as the sensitivity to epidermal growth factor receptor tyrosine kinase inhibitors in advanced non-small cell lung cancer (NSCLC); however, we need new predictive markers as well as driver mutations for better treatment options. The aim of this study is to investigate the predictive role of sarcopenia in lung adenocancer patients treated with erlotinib. Materials and Methods: This study was designed as retrospectively. Skeletal muscle index (SMI) was measured with a single cross-sectional area of the muscle at the third lumber vertebra (L3, cm²)/(height × height)(m²). Sarcopenia was defined by median cutoff values of SMI of women (<28.2 cm²/m²) and men (<32.7 cm²/m²). The predictive role of sarcopenia and other parameters was assessed by the cox-regression model. Results: The median age was 56 years (range, 36–84). Median progression-free survival (PFS) was 38 (95% confidence interval [CI]: 21.3–54.6) weeks in the sarcopenic group and 49 (95% CI: 0–101.4) weeks in the nonsarcopenic group (P = 0.053). In multivariate analysis, the presence of sarcopenia and number of metastatis were the independent predictive factors for PFS. Disease control rate and overall survival were not significantly different between sarcopenic and nonsarcopenic groups. Conclusion: We found that the presence of sarcopenia and number of metastasis were a predictive marker in NSCLC patients treated with erlotinib. It is important to recognize sarcopenia early and manage patients accordingly.