The Survival Effect of Neoadjuvant Therapy and Neoadjuvant Plus Adjuvant Therapy on Different AJCC 8th TNM Stages: A Propensity Score Matching Analysis Based on SEER Database

Abstract

Abstract Background: Currently, adjuvant therapy (AT) is the standard treatment for resectable pancreatic ductal adenocarcinoma (PDAC), and so is neoadjuvant therapy (NAT) for borderline resectable and locally advanced stages. However, it remains unclear whether AT improves survival after NAT and radical resection in all TNM stages. Methods: The studied population was comprised of patients diagnosed with PDAC who underwent radical surgery, and was drawn from the Surveillance, Epidemiology, and End Results (SEER) database, spanning from 2010 to 2019. we employed Pearson’s chi-square test, univariate and multivariate Cox regression analysis, Kaplan-Meier (K-M) analysis, Log-rank test, and emphasis on propensity score matching (PSM) analysis. Results: 13,868 PDAC patients were finally enlisted. After PSM, significant differences in survival were identified between AT and neoadjuvant therapy in combination with adjuvant therapy (NATAT) (p=0.023) as well as between NAT and NATAT (p<0.001). Upon stratified by AJCC 8th TNM stage, the survival advantage associated with AT was exclusively observed in stage III and stage IV, barring the subgroup T4N0M0. We also discovered that patients with potentially resectable diseases in stage III (T1-3N2M0) might have better survival upon receiving NATAT than AT alone, and some patients with NATAT in stage IV exhibited comparable survival to their counterparts without metastasis. Conclusion: In this retrospective cohort study, we demonstrated that patients harboring tumors in late TNM stages might benefit from supplementary AT in terms of survival, the NAT may be beneficial for resectable PDAC with more than 3 lymph nodes metastasis, and certain patients with M1 disease might still benefit from comprehensive systemic therapy and radical resection.