Postoperative dendritic cell vaccination in brain metastasis: A real-world retrospective cohort study evaluating survival and safety.

Brain metastasis (BM) is associated with poor prognosis and limited therapeutic options. Immunotherapy with dendritic cell (DC) vaccination represents a promising approach by potentially overcoming blood-brain barrier limitations while generating tumor-specific immune responses. This study evaluates the safety and preliminary efficacy of postoperative DC vaccination in patients with surgically resected BMs. We conducted a retrospective analysis of 17 patients (9 women, 8 men; mean age: 56.2 years) with BM from diverse primary cancers who received conventional treatment plus autologous DC vaccination between 2019 and 2022 at a single institution. Following tumor resection, patients received radiotherapy and/or systemic therapy alongside DC vaccination (2 × 108 DCs administered subcutaneously) over 6 months. Patients were assessed for adverse events, overall survival (OS), and survival relative to prognostic expectations based on diagnosis-specific graded prognostic assessment (DS-GPA). The median OS was 18 months (95% CI: 9-22), compared to historical median of 14.5 months for surgical resection alone. Patients receiving ≥ 6 vaccine doses demonstrated a median OS of 18 months (95% CI: 9-24) versus17 (95% CI: 3-24) for those receiving < 6 doses (Log-rank test, P = .39). Among 14 patients with available DS-GPA scores, 9 (64.3%) survived longer than their predicted median survival. No vaccine-related serious adverse events were observed, with reactions limited to grade 1 injection site reactions and low-grade fever. This real-world analysis suggests that postoperative DC vaccination for BM is safe and may confer survival benefit compared to historical outcomes. While limited by sample size and retrospective design, our findings warrant further investigation in prospective controlled trials to definitively establish efficacy and optimal integration into multimodal treatment approaches.