Efficacy, safety, and prognostic factors of capecitabine plus temozolomide regimen in patients with atypical thymic carcinoids

Background and objectives: Atypical thymic carcinoids (ATCs) are rare mediastinal malignancies that lack established treatment guidelines. Capecitabine and temozolomide (CapTem) has demonstrated significant efficacy in pancreatic neuroendocrine neoplasms (NENs), while its applicability and effectiveness in ATCs remain underexplored. This study seeks to investigate the efficacy, safety, and prognostic factors associated with CapTem in ATC patients. Design and methods: Thirty-eight ATC patients treated with CapTem at our center were analyzed. We assessed the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and treatment-related adverse effects. We also examined patients’ clinicopathological characteristics and their correlations with CapTem efficacy. Results: The cohort achieved a 15.8% ORR and 89.5% DCR, with a median PFS of 13.0 months. Multivariate analysis identified the platelet-to-lymphocyte ratio (PLR) as a significant independent prognostic factor for PFS, with a PLR ⩾ 235 associated with shorter PFS (7 months vs. undefined, p = 0.0004). Age was an independent prognostic factor for OS, with patients over 50 years experiencing shorter OS (36 months vs. undefined, p = 0.015). Safety analysis showed rare severe toxicities and no treatment-related fatalities. Conclusion: CapTem is an effective and well-tolerated treatment for ATC patients. Pretreatment PLR and age appear to be potential prognostic markers for CapTem therapy; however, these results warrant validation in larger patient cohorts.