Impact of thymosin alpha 1 as an immunomodulatory therapy on long-term survival of non-small cell lung cancer patients after R0 resection: a propensity score-matched analysis

Background: There is limited information about thymosin alpha 1 (T alpha 1) as adjuvant immunomodulatory therapy, either used alone or combined with other treatments, in patients with non-small cell lung cancer (NSCLC). This study aimed to evaluate the effect of adjuvant Tat treatment on long-term survival in margin-free (R0)-resected stage IA-ILIA NSCLC patients. Methods: A total of 5746 patients with pathologic stage IA-ILIA NSCLC who underwent R0 resection were included. The patients were divided into the Tat group and the control group according to whether they received Tat or not. A propensity score matching (PSM) analysis was performed to reduce bias, resulting in 1027 pairs of patients. Results: After PSM, the baseline clinicopathological characteristics were similar between the two groups. The 5-year disease-free survival (DFS) and overall survival (OS) rates were significantly higher in the Tat group compared with the control group. The multivariable analysis showed that Ted treatment was independently associated with an improved prognosis. A longer duration of T alpha 1 treatment was associated with improved OS and DFS. The subgroup analyses showed that T alpha 1 therapy could improve the DFS and/or OS in all subgroups of age, sex, Charlson Comorbidity Index (CCI), smoking status, and pathological rumor-node-metastasis (TNM) stage, especially for patients with non-squamous cell NSCLC and without targeted therapy. Conclusion: T alpha 1 adjuvant immunomodulatory therapy can significantly improve DFS and OS in patients with NSCLC after R0 resection, except for patients with squamous cell carcinoma and those receiving targeted therapy. The duration of T alpha 1 treatment is recommended to be >24 months.