Prognostic significance of T cells and NK cells in osteosarcoma: a dual-center retrospective study

Background There is no study on the relationship between peripheral blood different lymphocyte subtypes and the prognosis of osteosarcoma (OS). Therefore, this study aims to investigate the predictive value of T cells and natural killer (NK) cells for the prognosis of OS patients. Methods This study retrospectively analyzed the clinical data and preliminary laboratory indicators of patients with OS admitted from dual-center between January 2014 and January 2021. The receiver operating characteristic (ROC) curve was employed to determine optimal cutoff values for different lymphocyte subtypes, with T cells, NK cells, and B lymphocytes subsequently stratified into high- and low-proportion groups based on their respective optimal cutoff values. Kaplan-Meier curve was employed to analyze the impact of different lymphocyte on survival time and status. Univariate and multivariate Cox analyses were performed on clinical and laboratory indicators to identify independent prognostic factors influencing the prognosis of OS patients. Results After screening 277 patients with OS, a total of 106 patients were eligible for this study. The median follow-up time was 36.00 months. At the last follow-up, patients were categorized as having a good prognosis if they survived or a poor prognosis if they died: good prognosis (n = 48) and poor prognosis (n = 58). Kaplan-Meier curve revealed that patients with a high proportion of T (Median overall survival: 41 months vs. 32 months, P = 0.007) and NK (Median overall survival: 44 months vs. 32 months, P = 0.004) cells had a better prognosis compared to those with a low proportion. Univariate analysis indicated that age, body mass index (BMI), C-reactive protein (CRP), tumor size, Enneking stage, surgical method, and the proportions of T, NK, and B cells were associated with the prognosis of OS patients (P < 0.05). Multivariate analysis indicated that Enneking stage (II vs. I, HR = 12.543, P = 0.015; III vs. I, HR = 29.078, P = 0.001), and the proportions of T and NK cells (HR = 0.466, P = 0.048; HR = 0.497, P = 0.029) were independent factors influencing the prognosis of OS patients (P < 0.05). Conclusion The proportions of T and NK cells may serve as efficient and practical prognostic indicators for OS patients, with higher proportions often associated with a better prognosis.