Main Session
Sep 28
PQA 04 - Breast Cancer, Patient Reported Outcomes/QoL/Survivorship, Functional Radiation Medicine, Hematologic Malignancies, Palliative Care, and International/Global Oncology

2749 - Comparison of Ultrahypofractionated Radiotherapy In Breast Cancer to Longer Schedules: A Meta-Analysis of Randomized Trials

03:00pm - 04:00pm ET
Poster Hall - Exhibit Hall A
Screen: 4
POSTER

Presenter(s)

Juliane Hoerner-Rieber, MD Headshot
Juliane Hoerner-Rieber, MD - University Hospital Duesseldorf, Düsseldorf, Nordrhein-

J. Haussmann1, T. Sander2, L. Schmidt3, L. M. Irschfeld2, J. Neuwahl2, W. Budach1, D. Jazmati4, and J. Hoerner-Rieber5; 1Department of Radiation Oncoloy, Heinrich Heine University, Dusseldorf, Germany, 2Heinrich Heine University, Dusseldorf, Germany, 3Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany, 4Medical Faculty Heinrich Heine University, Dusseldorf, Germany, 5University Hospital Duesseldorf, Department of Radiation Oncology, Düsseldorf, Nordrhein-, Germany

Purpose/Objective(s):

Moderately hypofractionated radiotherapy is now the standard approach for adjuvant irradiation in breast cancer. Several prospective randomized trials have investigated further shortening of treatment to 1–2 week regimens. The oncologic efficacy and tolerability of these treatment concepts were analyzed.

Materials/Methods:

A systematic literature review was conducted to identify studies comparing ultrahypofractionated (UHFx) regimens (5–10 fractions) with longer fractionation schedules, including hypofractionated or conventionally fractionated radiotherapy (HFx/CFx; 15–28 fractions). Evaluated endpoints included ipsilateral breast tumor recurrence (IBTR), locoregional recurrence (LRC), distant metastasis (DM), recurrence-free interval (RFI), breast cancer–specific survival (BCSS), and overall survival (OS). Toxicity rates were also assessed. Hazard ratios and event rates were extracted from the published studies.

Results:

The literature search identified nine randomized trials comprising a total of 11,666 patients. The median follow-up was 5.4 years. Analysis of local recurrence demonstrated no significant difference between treatment approaches (HR = 0.83; 95% CI: 0.62–1.12; p = 0.230; OR = 0.90; 95% CI: 0.68–1.18; p = 0.435). Similarly, no significant differences were observed for other oncologic endpoints, including LRC, DM, RFI, OS, and BCSS. UHFx was associated with higher rates of chronic toxicity, including breast shrinkage, breast induration, and telangiectasia. No significant differences were observed for other outcomes, including breast edema, lymphedema, or cosmetic results.

Conclusion:

Ultrahypofractionated radiotherapy demonstrates no differences in oncologic outcomes compared with the current standard in prospective randomized trials. However, certain UHFx regimens are associated with increased rates of specific chronic toxicities. Therefore, the substantially shorter treatment duration must be carefully weighed against these potential disadvantages. Further subgroup analyses may help identify patient populations that particularly benefit from UHFx.