title: Effect of radiotherapy after breast-conserving surgery for ductal carcinoma in situ: 20 years follow-up in the randomized SweDCIS Trial.
abstract: OBJECTIVE
  Four randomized studies show that adjuvant radiotherapy (RT) lowers the risk of subsequent ipsilateral breast events (IBEs) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) by approximately 50% after 10 to 15 years. We present 20 years of follow-up data for the SweDCIS trial.
  
  
  METHODS
  Between 1987 and 1999 1,046 women were randomly assigned to RT or not after BCS for primary DCIS. Results up to 2005 have been published, and we now add another 7 years of follow-up. All breast cancer events and causes of death were registered.
  
  
  RESULTS
  There were 129 in situ and 129 invasive IBEs. Absolute risk reduction in the RT arm was 12.0% at 20 years (95% CI, 6.5 to 17.7), with a relative risk reduction of 37.5%. Absolute reduction was 10.0% (95% CI, 6.0 to 14.0) for in situ and 2.0% (95% CI, -3.0 to 7.0) for invasive IBEs. There was a nonstatistically significantly increased number of contralateral events in the RT arm (67 v 48 events; hazard ratio, 1.38; 95% CI, 0.95 to 2.00). Breast cancer-specific death and overall survival were not influenced. Younger women experienced a relatively higher risk of invasive IBE and lower effect of RT. The hazard over time looked different for in situ and invasive IBEs.
  
  
  CONCLUSIONS
  Use of adjuvant RT is supported by 20-year follow-up. Modest protection against invasive recurrences and a possible increase in contralateral cancers still call for a need to find groups of patients for whom RT could be avoided or mastectomy with breast reconstruction is indicated.
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom. fredrik.warnberg@akademiska.se.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Wärnberg
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Hans
authors.initials: H
authors.lastname: Garmo
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Stefan
authors.initials: S
authors.lastname: Emdin
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Veronica
authors.initials: V
authors.lastname: Hedberg
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Linda
authors.initials: L
authors.lastname: Adwall
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Sandelin
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Anita
authors.initials: A
authors.lastname: Ringberg
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Per
authors.initials: P
authors.lastname: Karlsson
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Lars-Gunnar
authors.initials: LG
authors.lastname: Arnesson
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Harald
authors.initials: H
authors.lastname: Anderson
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Karin
authors.initials: K
authors.lastname: Jirström
authors.affiliation: Fredrik Wärnberg, Hans Garmo, Linda Adwall, and Lars Holmberg, Uppsala University, Uppsala; Stefan Emdin, Umeå University Hospital, Umeå; Veronica Hedberg, Gävle Hospital, Gävle; Kerstin Sandelin, Karolinska University Hospital, Stockholm; Anita Ringberg, Skåne University Hospital, Malmö; Anita Ringberg, Harald Anderson, and Karin Jirström, Lund University, Lund; Per Karlsson, Sahlgrenska University Hospital, Göteborg; Lars-Gunnar Arnesson, Linköping University Hospital, Linköping, Sweden; and Hans Garmo and Lars Holmberg, King's College London Medical School, London, United Kingdom.
authors.forename: Lars
authors.initials: L
authors.lastname: Holmberg
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery*; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008327:Mammography / Q000379:methods; D008403:Mass Screening / Q000379:methods; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D013548:Sweden; D013997:Time Factors