title: Effect of Time Interval between Breast-Conserving Surgery and Radiation Therapy on Outcomes of Node-Positive Breast Cancer Patients Treated with Adjuvant Doxorubicin/Cyclophosphamide Followed by Taxane.
abstract: OBJECTIVE
  This study evaluated the effect of surgery-radiotherapy interval (SRI) on outcomes in patients treated with adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) and adjuvant four cycles of doxorubicin/cyclophosphamide (AC) followed by four cycles of taxane.
  
  
  METHODS
  From 1999 to 2007, 397 eligible patients were diagnosed. The effect of SRI on outcomes was analyzed using a Cox proportional hazards model, and a maximal chi-square method was used to identify optimal cut-off value of SRI for each outcome.
  
  
  RESULTS
  The median SRI was 6.7 months (range, 5.6 to 10.3 months). A SRI of 7 months was the significant cut-off value for distant metastasis-free survival (DMFS) and disease-free survival (DFS) using a maximal chi-square method. For overall survival, a significant cut-off value was not found. The patients with SRI > 7 months had worse 6-year DMFS and DFS than those with SRI ≤ 7 months on univariate analysis (DMFS, 81% vs. 91%, p=0.003; DFS, 78% vs. 89%, p=0.002). On multivariate analysis, SRI > 7 months did not affect DMFS and DFS.
  
  
  CONCLUSIONS
  RT delayed for more than 7 months after BCS and adjuvant four cycles of AC followed by four cycles of taxane did not compromise clinical outcomes.
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.|Department of Radiation Oncology, Konkuk University Medical Center, Seoul, Korea.
authors.forename: Hyeon Kang
authors.initials: HK
authors.lastname: Koh
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.|Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: In Hae
authors.initials: IH
authors.lastname: Park
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Keun Seok
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Jungsil
authors.initials: J
authors.lastname: Ro
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: So-Youn
authors.initials: SY
authors.lastname: Jung
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Seeyoun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Kang
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eui Kyu
authors.initials: EK
authors.lastname: Chie
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Wonshik
authors.initials: W
authors.lastname: Han
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Noh
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung-Hun
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sung Whan
authors.initials: SW
authors.lastname: Ha
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D003520:Cyclophosphamide / Q000627:therapeutic use*; D004317:Doxorubicin / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D018714:Radiotherapy, Adjuvant; D043823:Taxoids / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D043823:Taxoids; D004317:Doxorubicin; D003520:Cyclophosphamide
keywords: Adjuvant chemotherapy; Breast neoplasms; Radiotherapy; Segmental mastectomy; Time-to-treatment