Survival benefit of adjuvant chemotherapy and individualized prognosis in resected cHCC-CCA.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare malignancy with poor prognosis and unclear benefit from adjuvant chemotherapy. To identify the appropriate candidates for postoperative adjuvant chemotherapy in cHCC-CCA, we developed a prognostic model to predict patient outcomes and stratify populations accordingly. This retrospective study included 75 cHCC-CCA patients treated at Tianjin Medical University Cancer Institute and Hospital from 2009 to 2019. Prognostic factors were identified via univariate and multivariate Cox regression. Model performance was assessed using ROC curves, calibration plots, and decision curve analysis. Propensity score matching (PSM) was applied to reduce bias. Adjuvant chemotherapy significantly improved overall survival (OS) in Kaplan-Meier (p = 0.029) and PSM analyses (p = 0.0011). Five independent prognostic factors were identified: macrovascular invasion, lymph node metastasis, the largest tumor size >5 cm, the high expression of CD8, and the high expression of FOXP3. The nomogram showed good predictive performance. Among high-risk patients stratified by the nomogram, those receiving adjuvant chemotherapy had longer OS (p = 0.013), while no significant benefit was observed in the low-risk group (p = 0.084). Adjuvant chemotherapy improves postoperative survival in cHCC-CCA. The nomogram provides individualized risk stratification and may inform treatment decisions.