title: Optimal radiation dose for patients with one to three lymph node positive breast cancer following breast-conserving surgery and anthracycline plus taxane-based chemotherapy: A retrospective multicenter analysis (KROG 1418).
abstract: OBJECTIVE
  This study was performed to determine optimal radiation dose in pN1 breast cancer patients who received breast conserving surgery (BCS) and anthracycline plus taxane (AT)-based chemotherapy.
  
  
  METHODS
  Retrospective chart reviews were performed in 1,147 patients who were treated between January 2006 and December 2010. The impact of radiation dose on treatment outcomes was evaluated.
  
  
  RESULTS
  Median follow-up time was 66 months. The 5-year rate of disease-free survival (DFS) was 93.2%. Larger tumor size (> 20 mm), positive lymphovascular invasion, high histologic grade, and high ratio of positive nodes (> 0.1) were significantly associated with inferior DFS. By using the 4 factors related to DFS, patients were categorized into high-risk (with ≥ 3 factors) and low-risk (with < 3 factors) groups. In the high-risk group, higher radiation dose (> 60.3 GyEQD2) was significantly associated with better DFS than the lower dose (≤ 60.3 GyEQD2). However, the radiation dose did not impact DFS in the low-risk group.
  
  
  CONCLUSIONS
  Dosing of radiation affects the outcome of post-BCS radiotherapy in pN1 breast cancer. Doses of over 60.3 GyEQD2 were associated with better outcome in the high-risk patients.
authors: Department of Radiation Oncology, Hallym University Dongtan Sacred Heart Hospital, Hwaseong, Gyeonggi, South Korea.
authors: Haeyoung
authors: H
authors: Kim
authors: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors: Won
authors: W
authors: Park
authors: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors: Jeong Il
authors: JI
authors: Yu
authors: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors: Doo Ho
authors: DH
authors: Choi
authors: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors: Seung Jae
authors: SJ
authors: Huh
authors: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, South Korea.
authors: Yeon-Joo
authors: YJ
authors: Kim
authors: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, South Korea.
authors: Eun Sook
authors: ES
authors: Lee
authors: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, South Korea.
authors: Keun Seok
authors: KS
authors: Lee
authors: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, South Korea.
authors: Han-Sung
authors: HS
authors: Kang
authors: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, South Korea.
authors: In Hae
authors: IH
authors: Park
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, South Korea.
authors: Kyung Hwan
authors: KH
authors: Shin
authors: Department of Radiation Oncology, Ewha Womans University Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, South Korea.
authors: Kyubo
authors: K
authors: Kim
authors: Department of Radiation Oncology, Ewha Womans University Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, South Korea.
authors: Kyung Ran
authors: KR
authors: Park
authors: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea.
authors: Yong Bae
authors: YB
authors: Kim
authors: Department of Radiation Oncology, Chonnam National University Medical School, Gwangju, South Korea.
authors: Sung Ja
authors: SJ
authors: Ahn
authors: Department of Radiation Oncology, St. Vincent's Hospital, The Catholic University of Korea College of Medicine, Suwon, South Korea.
authors: Jong Hoon
authors: JH
authors: Lee
authors: Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors: Jin Hee
authors: JH
authors: Kim
authors: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Gyeonggi, South Korea.
authors: Mison
authors: M
authors: Chun
authors: Department of Radiation Oncology, Dong-A University Hospital, Dong-A University School of Medicine, Busan, South Korea.
authors: Hyung-Sik
authors: HS
authors: Lee
authors: Department of Radiation Oncology, Chonbuk National University Medical School, Jeonju, Jeollabuk, South Korea.
authors: Jung Soo
authors: JS
authors: Kim
authors: Department of Radiation Oncology, Wonju Severance Christian Hospital, Wonju, Kangwon, South Korea.
authors: Jong-Young
authors: JY
authors: Lee
mesh_terms: D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D001952:Bridged-Ring Compounds / Q000627:therapeutic use; D018572:Disease-Free Survival; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011829:Radiation Dosage; D012189:Retrospective Studies; D043823:Taxoids / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D018943:Anthracyclines; D000970:Antineoplastic Agents; D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane
keywords: breast neoplasms; dose-response relationship; prognosis; radiotherapy