Decisions Regarding Accelerated Partial-Breast Irradiation in a Population-Based Sample of Early-Stage Breast Cancer Patients

Abstract

Results: A total of 53,431 articles were screened, with consensus from both investigators on the articles included. In total, 10 clinical studies met inclusion criteria, with 268 patients treated by ablative therapies for MBC. Fourteen patients were treated with metastasectomy, 82 with radioembolization with Yttrium-labelled microspheres, 48 with radiofrequency ablation, 89 with SRS/SBRT, and 35 with a combination of SRS/SBRT and metastasectomy. Median OS was 28 months (range 8.2-60) amongst the reported studies. In 2 studies, median OS was not reached. PFS was poorly reported, but varied from 26% to 80% at 4-5-years. Initial analysis demonstrated improved PFS and OS in patients with limited metastatic lesions, disease confined to a single organ, and management with localized therapies as opposed to systemic treatment alone. Conclusion: MBC patients treated with ablative therapies represent a heterogeneous population that can benefit from long term PFS and OS when presenting with limited disease burden. The best predictors of PFS and OS were the number of metastatic lesions and single organ involvement, encouraging the consideration of these variables in future studies. Comparison of survival estimates versus trials using systemic therapy alone is warranted in order to determine the minimal clinically important differences for future randomized trial design. Author Disclosure: M.J. Kucharczyk: None. A. Swaminath: None.