Early Breast Cancer or DCIS: Hypofractionated Versus Standard-Fractionated Radiotherapy
Posted: Monday, September 28, 2020
Using moderately hypofractionated irradiation to treat ductal carcinoma in situ (DCIS) or node-negative breast cancer did not produce more breast induration when compared with standard fractionated therapy. Additionally, the risk of locoregional recurrence of these cancers was low after hypofractionated irradiation. These results were communicated in an article published in the Journal of Clinical Oncology by Jens Overgaard, MD, DMSc, of Aarhus University, Denmark, and colleagues.
“[This] trial provides long-term robust evidence in favor of hypofractionated whole-breast radiotherapy for patients with breast cancer and DCIS,” concluded the authors.
The trial enrolled 1,854 patients older than age 40 who underwent breast-conserving surgery for node-negative breast cancer or DCIS between 2009 and 2014. Of this group, 1,608 had adenocarcinoma, and 246 had DCIS. Patients were then randomly assigned 1:1 to receive radiotherapy at a dose of 50 Gy in 25 fractions or 40 Gy in 15 fractions.
After a median follow-up of 7.26 years, the rate of grade 2 or 3 induration at 3 years was 11.8% in the group receiving 50-Gy fractions and 9.0% in the group receiving 40-Gy fractions (P = .07). The overall risk of induration was 13% in the 50-Gy group and 11% in the 40-Gy group (odds ratio = 0.80, P = .029). Systemic therapies and radiotherapy boost did not increase the risk of induration. The overall effects on normal tissue, including telangiectasia, dyspigmentation, scar appearance, edema, pain, and patient satisfaction, were similar between the 50-Gy and 40-Gy groups as well. Excellent or good cosmetic outcomes were reported by 90% of patients at 3 years and 85% of patients at 5 years.
The 9-year risk of locoregional recurrence was 3.3% and 3.0% in the 50-Gy and 40-Gy groups, respectively. The 9-year overall survival rate was 93.4% among patients treated with 50 Gy and 93.4% among patients treated with 40 Gy.
Disclosures: For a full list of authors disclosures, visit ascopubs.org.