title: A Comparative Study of Daily 3-Gy Hypofractionated and 1.8-Gy Conventional Breast Irradiation in Early-Stage Breast Cancer.
abstract: We retrospectively compared accelerated hypofractionation (AHF) with conventional fractionation (CF) in the radiation therapy (RT) for early-stage breast cancer patients.Three hundred seventy-nine early-stage (pT1-2 and pN0-1a) breast cancer patients who received RT with AHF after breast-conserving surgery (BCS) were included. These patients were matched with 379 corresponding patients who received BCS and RT with CF at a different center with respect to the year BCS was performed, patient age (±3 years), and cancer stage. The AHF regimen consisted of 39 Gy in 13 fractions to the whole breast and a consecutive boost of 9 to 12 Gy in 3 to 4 fractions to the tumor bed. CF comprised whole-breast irradiation up to 50.4 Gy in 28 fractions and a boost of 9 to 14 Gy in 5 to 7 fractions to the tumor bed.The median follow-up period was 75 months (range, 3.8-110.8 months). There was no statistically significant difference between the AHF and CF groups in terms of age distribution, T and N stage, resection margin, and histologic grade. There were 5 ipsilateral breast tumor relapse (IBTR) cases in the AHF group compared with 7 cases in the CF group. Seven and eight locoregional relapse (LRR) cases were observed in the AHF and CF groups, respectively. The 7-year rates of IBTR-free survival, LRR-free survival, and disease-free survival were 98.9%, 98.4%, and 97.1% in the AHF group and 98.1%, 97.9%, and 96.0% in the CF group, respectively (P > 0.05). The incident rates of grade 3 edema, hyperpigmentation, or wet desquamation at the end of RT were higher in the CF group than in the AHF group (16.4% vs 0.2%, respectively; P < 0.01).AHF RT of 39 Gy to the whole breast plus a 9-Gy boost in 16 fractions showed excellent tumor control and tolerable skin toxicity, a finding that is comparable to CF RT in patients with early-stage breast cancer.
authors.affiliation: From the Seoul National University College of Medicine, Seoul (S-WL, KHS, KK, EKC, WH, S-AI); and Research Institute and Hospital, National Cancer Center, Goyang, Korea (Y-JK, S-YJ, KSL, ESL).
authors.forename: Sea-Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Yeon-Joo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.forename: Eui Kyu
authors.initials: EK
authors.lastname: Chie
authors.forename: Wonshik
authors.initials: W
authors.lastname: Han
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.forename: So-Youn
authors.initials: SY
authors.lastname: Jung
authors.forename: Keun Seok
authors.initials: KS
authors.lastname: Lee
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000209:etiology; D009367:Neoplasm Staging; D000069473:Radiation Dose Hypofractionation; D012189:Retrospective Studies