title: Accelerated whole breast irradiation in early breast cancer patients with adverse prognostic features.
abstract: OBJECTIVE
  Accelerated whole breast irradiation (AWBI) and conventional whole breast irradiation (CWBI) were compared to determine whether AWBI is as effective as CWBI in patients with early breast cancer and adverse prognostic features.
  
  
  METHODS
  We included 330 patients who underwent breast-conserving surgery (BCS) and post-operative radiation therapy (RT) using AWBI for pT1-2 and pN0-1a breast cancer from 2007 to 2010. These patients were matched with 330 patients who received CWBI according to stage, age (±3 years), and the year of BCS. AWBI of 39 Gy and CWBI of 50.4 Gy were given in 13 and 28 fractions, respectively.
  
  
  RESULTS
  Median follow-up time was 81.9 months. There were no statistically significant differences between the AWBI and CWBI groups in terms of age, stage, tumor grade, or molecular subtype. More patients with Ki-67 index ≥ 14% were present in the AWBI group (AWBI 47.0% vs. CWBI 10.3%; P<0.01). The 5-year ipsilateral breast tumor relapse (IBTR) rates for the AWBI and CWBI groups were 0.8% and 1.8%, respectively (P=0.54). High tumor grade was a statistically significant risk factor for IBTR (5-year IBTR rate: 2.9%; P=0.01). Ki-67 ≥ 14% was marginally related to IBTR (5-year IBTR rate: 2.2%; P=0.07). There were no statistically significant differences in the hazard ratios between the AWBI and CWBI groups according to any of the risk factors. There were no acute grade 3 toxicities in the AWBI group. There were no late grade 3 toxicities in either group.
  
  
  CONCLUSIONS
  AWBI is comparable to CWBI in early breast cancer with adverse prognostic features.
authors: Seoul National University, College of Medicine, Seoul, Korea.|Catholic University of Korea, College of Medicine, Seoul, Korea.
authors: Sea-Won
authors: SW
authors: Lee
authors: Seoul National University, College of Medicine, Seoul, Korea.
authors: Kyung Hwan
authors: KH
authors: Shin
authors: Seoul National University, College of Medicine, Seoul, Korea.
authors: Eui Kyu
authors: EK
authors: Chie
authors: Seoul National University, College of Medicine, Seoul, Korea.
authors: Jin Ho
authors: JH
authors: Kim
authors: Seoul National University, College of Medicine, Seoul, Korea.
authors: Seock-Ah
authors: SA
authors: Im
authors: Seoul National University, College of Medicine, Seoul, Korea.
authors: Wonshik
authors: W
authors: Han
authors: Seoul National University, College of Medicine, Seoul, Korea.
authors: Dong-Young
authors: DY
authors: Noh
authors: Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors: Hyeon Woo
authors: HW
authors: Lim
authors: Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors: Tae Hyun
authors: TH
authors: Kim
authors: Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors: Keun Seok
authors: KS
authors: Lee
authors: Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors: Eun Sook
authors: ES
authors: Lee
authors: Catholic University of Korea, College of Medicine, Seoul, Korea.
authors: Soo Yoon
authors: SY
authors: Sung
authors: Ewha Womans University, School of Medicine, Seoul, Korea.
authors: Kyubo
authors: K
authors: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018450:Disease Progression; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D012307:Risk Factors; D066106:Seoul; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D019394:Ki-67 Antigen
keywords: early breast cancer; hypofractionation; risk factor