Association and predictive value of sarcopenic obesity for the prognosis of lung cancer patients receiving immune checkpoint inhibitors

Background Sarcopenic obesity (SO) has been established as a reliable predictor of prognosis for several cancer types; however, its role in the prognosis of lung cancer patients receiving immune checkpoint inhibitors (ICIs) remains unclear. This study aimed to explore the potential predictive value of SO on survival outcomes in lung cancer patients undergoing ICI therapy. Methods From May 2018 to October 2020, lung cancer patients who received immunotherapy at a tertiary hospital in Henan Province were retrospectively evaluated using data from the electronic medical record system. Data on demographic characteristics, biochemical markers, current illnesses and treatments, and nutrition-related information were documented. Sarcopenia was evaluated using the skeletal muscle index (SMI) (cm 2 /m 2 ), which was calculated by measuring the muscle mass area from a cross-sectional CT image at the L3 vertebra level prior to immunotherapy. Results The 119 participants were divided into four groups: control, sarcopenia, obesity, and SO. Among these participants, 15.13% were diagnosed with SO. The results demonstrated that for 3-year survival rates, patients with SO had the highest mortality rate (with a median survival of 22.55 months), followed by those with sarcopenia alone (median survival: 28.29 months) and those with obesity alone (median survival: 28.99 months) ( p < 0.05). Multivariate Cox regression analysis indicated that SO ( HR = 3.479, 95% CI = 1.374–8.814), creatinine level ( HR = 0.963, 95% CI = 0.936–0.990), receiving ICIs as second-line therapy ( HR = 4.274, 95% CI = 1.941–9.411), receiving ICIs as third-line or later therapy ( HR = 2.980, 95% CI = 1.169–7.597), and an Eastern Cooperative Oncology Group performance status (ECOG-PS) score of ≥3 ( HR = 5.274, 95% CI = 2.670–10.418) are independent factors associated with reduced 3-year survival time. Conclusion SO is an independent prognostic factor for lung cancer patients receiving immunotherapy. Early identification and targeted management of sarcopenic obesity are crucial for optimizing treatment strategies and improving survival outcomes in ICI-treated lung cancer patients.