Kuranishi F, Miyazaki T, Tagashira T, Fujii A, Yuba M, Miyake I, Fujita T, Suzuki T, Masuda H,
Makihata T, Nakagou S, Ohno T. Thirty-Five-Year Follow-Up Real-World Data Revealed the Efficacy of Autologous Formalin-Fixed Tumor Vaccine on Metastatic Breast Cancer-A Target Trial Emulation. Clin Breast Cancer. 2025 Dec;25(8):e1011-e1022.e5. doi: 10.1016/j.clbc.2025.06.008. Epub 2025 Jun 27.
Abstract
Background and Methods: The prognosis after distant metastasis of breast cancer is generally poor. We analyzed the effect of an autologous formalin-fixed tumor vaccine (AFTV) on postoperative breast cancer using 35-year follow-up real-world data in a concurrent cohort and a target trial emulation, a similar method to the randomized study. The sample (n=698) was narrowed to cases with distant metastasis, resulting in a cohort of 94 patients. In this study, meta-OS refers to overall survival after distant metastasis.
Results: Treatment with AFTV significantly prolonged meta-OS. The median meta-OS was 4.58 years for the AFTV group (n=59) compared to 2.81 years for the control group (n=35), with a significant difference (p=0.0300). Radiotherapy (RT), a stratified factor, also extended meta-OS, although no superiority was observed between AFTV therapy and RT in multivariable regression analysis. The combination of AFTV therapy and RT demonstrated a synergistic effect in prolonging meta-OS (p=0.0320). Chemotherapy (Chemo) alone showed no significant effect on meta-OS in the control group but shortened meta-OS in the AFTV group, if administered within 6 months of AFTV treatment (p=0.0478). Treating after distant metastasis, the “Optimum AFTV Set” subgroup (AFTV therapy plus RT without Chemo within 6 months, n=13) extracted from the AFTV group had a median meta-OS of 12.85 years, showing a significant improvement compared to the corresponding control subgroup (RT without Chemo within 6 months) (n=6, p=0.00819). The 10-year survival rate after distant metastasis was 25.6% in the AFTV group, 7.4% in the control group, 53.8% in the Optimum AFTV Set subgroup, and 0% in the corresponding control subgroup. All AFTV-related adverse events were classified as CTCAE grade 2 or lower.
Discussion: The results of Optimum AFTV Set therapy provide a strong rationale for a larger-scale prospective randomized study.
Conclusion: The present real-world data suggest that Optimum AFTV Set therapy may be a useful option for treatment following the detection of distant metastasis after breast cancer surgery.
