A recent study presented at the 2024 American Society for Radiation Oncology (ASTRO) Annual Meeting suggests that ultra-hypofractionated radiation (UHFRT) may offer a well-tolerated and effective treatment option for elderly patients with low-risk, early-stage breast cancer. The research, led by Bin Gui, MD, from the Northwell Health Cancer Institute, explored the efficacy of UHFRT in this specific population, addressing a gap in previous research.
The study involved 71 patients with a median age of 73 years who met the low-risk inclusion criteria. These patients were treated with either a whole-breast radiation regimen based on the phase 3 FAST-Forward trial or accelerated partial breast irradiation (APBI) regimens. The primary aim was to assess the initial outcomes of UHFRT in older patients who might otherwise be considered for radiation omission.
Key Findings on Efficacy and Safety
After a median follow-up of 10 months, the study reported no ipsilateral breast tumor recurrence (IBTR) in the UHFRT cohort. Furthermore, there were no grade 3 or 4 toxicities observed. Low-grade acute and late toxicities were minimal, with similar outcomes noted whether UHFRT was administered alone or in combination with endocrine therapy. Specifically, grade 2 acute toxicity, late toxicity, and cosmetic outcomes were all low across both treatment arms.
"The older patients with more comorbidities and intolerance of endocrine therapy are ideal for these radiation regimens with UHFRT," Gui stated. He further emphasized that these regimens may offer patients great options to improve local control with low toxicity rates.
UHFRT as a Convenient Treatment Approach
UHFRT, typically delivered in 5 fractions over approximately one week, has previously demonstrated efficacy in controlling local recurrence in patients with early-stage breast cancer, as shown in the phase 3 FAST-Forward trial and APBI trials. However, its specific role in older patients had not been thoroughly investigated. The PRIME II study indicated that radiation omission could be an option for older patients, but many in this age group have diminished compliance with endocrine therapy, which was crucial in that study.
In Gui's study, compliance with UHFRT was 100%, contrasting with the 24% compliance rate observed for endocrine therapy, often due to adverse effects or refusal. This suggests that UHFRT could be a more reliable treatment option for older patients who struggle with endocrine therapy.
Implications and Future Directions
The findings suggest that UHFRT offers a convenient and easily tolerated treatment approach for older patients seeking to reduce the rate of local recurrence. The absence of significant differences in acute toxicity, late toxicity, and cosmetic outcomes between radiation plus endocrine therapy and radiation alone provides clinicians with additional flexibility in tailoring treatment plans.
While these initial results are promising, Gui noted that further prospective studies are necessary to confirm these findings and to better understand the long-term outcomes of UHFRT in older patients with low-risk breast cancer.
