Accelerated Partial-Breast vs Whole-Breast Irradiation After Breast-Conserving Surgery
As reported in The Lancet Oncology by Polgár et al, 5-year late side effects and cosmetic results were similar with accelerated partial-breast irradiation (APBI) with interstitial brachytherapy vs whole-breast irradiation (WBI) after breast-conserving surgery for low-risk invasive and in situ carcinoma in a European phase III trial.
Previously reported results of the trial showed noninferiority of APBI with interstitial brachytherapy vs WBI in 5-year local control, disease-free survival, and overall survival.
The current analysis included 1,184 patients (of 1,328 total patients) in the as-treated population, including 551 in the WBI group and 633 in the APBI group. Median follow-up was 6.6 years.
Late Effects and Cosmetic Outcomes
No patients had grade 4 toxicities. For the APBI vs WBI groups: < 1% vs 2% had grade 3 late skin toxicity (P = .16); 0% vs < 1% had grade 3 late subcutaneous tissue toxicity (P = .10); 23.3% vs 27.0% had any late side effect of ≥ grade 2 at 5 years (P = .12); 6.9% vs 10.7% had grade 2 or 3 late skin toxicity at 5 years (P = .020); 12.0% vs 9.7% had grade 2 or 3 late subcutaneous tissue side effects at 5 years (P = .28); 8.4% vs 11.9% had grade 2 or 3 breast pain (P = .074); 92% vs 91% of patients judged their cosmetic results to be excellent to good at 5 years (P = .62) and 93% vs 90% of their physicians judged results to be excellent to good (P = .12).
No treatment-related deaths were observed. A total of 3 patients in each group died of breast cancer, and 14 patients in the APBI group and 21 patients in the WBI group died of unrelated causes.
The investigators concluded: “5-year toxicity profiles and cosmetic results were similar in patients treated with breast-conserving surgery followed by either APBI with interstitial brachytherapy or conventional WBI, with significantly fewer grade 2–3 late skin side effects after APBI with interstitial brachytherapy. These findings provide further clinical evidence for the routine use of interstitial multicatheter brachytherapy-based APBI in the treatment of patients with low-risk breast cancer who opt for breast conservation.”
The study was funded by German Cancer Aid.
Csaba Polgár, MD, of the National Institute of Oncology, Budapest, is the corresponding author of The Lancet Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
