The survival effect of neoadjuvant therapy and neoadjuvant plus adjuvant therapy on pancreatic ductal adenocarcinoma patients with different TNM stages: a propensity score matching analysis based on the SEER database

Background: Adjuvant therapy (AT) and neoadjuvant therapy (NAT) are standard treatments for pancreatic ductal adenocarcinoma (PDAC) depending on the status of the disease. However, whether AT improves survival after NAT and radical resection in all TNM stages remains unclear. Research design and methods: We utilized the Surveillance, Epidemiology, and End Results (SEER) database (2010-2019) for PDAC patients who underwent radical surgery and applied Pearson's chi-square test, multivariate and univariate Cox regression, Kaplan-Meier plot, Log-rank tests, and propensity score matching (PSM) for analysis. Results: Given PSM after enrolling 13,868 PDAC patients, significant differences in survival were identified between AT and neoadjuvant therapy plus adjuvant therapy (NATAT) (p = 0.023) as well as between NAT and NATAT (p < 0.001). According to the AJCC 8th TNM stage, a survival advantage associated with NATAT was exclusively observed in stage III and IV disease, except for T4N0M0. Some stage IV patients receiving NATAT exhibited comparable survival to their counterparts without metastasis. Conclusions: In this retrospective cohort study, we demonstrated that patients harboring tumors in late TNM stages, including N2 resectable PDAC, might have better survival from NATAT, and that certain patients with M1 disease might still benefit from comprehensive systemic therapy and radical resection.