title: No clear effect of postoperative radiotherapy on survival of breast cancer patients with one to three positive nodes: a population-based study.
abstract: BACKGROUND
  In published radiotherapy trials, the failure rate in the control arm among patients with one to three positive nodes is high compared with that seen with modern adjuvant treatments. Therefore, the generalizability of the results has been questioned. The aim of the present study was to compare relative survival in breast cancer patients between two Swedish regions with screening mammography programs and adjuvant treatment guidelines similar with the exception of the indication of radiotherapy for patients with one to three positive nodes.
  
  
  METHODS
  Between 1989 and 2006, breast cancer patients were managed very similarly in the west and southeast regions, except for indication for postoperative radiotherapy. In patients with one to three positive nodes, postmastectomy radiotherapy was generally given in the southeast region (89% of all cases) and generally not given in the west region (15% of all cases). For patients with one to three positive nodes who underwent breast-conserving surgery, patients in the west region had breast radiotherapy only, while patients in the southeast region had both breast and lymph nodes irradiated.
  
  
  RESULTS
  The 10-year relative survival for patients with one to three positive lymph nodes was 78% in the west region and 77% in the southeast region (P = 0.12). Separate analyses depending on type of surgery, as well as number of examined nodes, also revealed similar relative survival.
  
  
  CONCLUSIONS
  Locoregional postoperative radiotherapy has well-known side-effects, but in this population-based study, there was little or no influence of this type of radiotherapy on survival when one to three lymph nodes were involved.
authors.affiliation: Department of Medicine, Southern Älvsborg Hospital, Borås; Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg.
authors.forename: A E
authors.initials: AE
authors.lastname: Nordenskjöld
authors.affiliation: Regional Cancer Center South East Sweden, Linköping; Department of Clinical and Experimental Medicine and Department of Oncology, Linköping University, Linköping.
authors.forename: H
authors.initials: H
authors.lastname: Fohlin
authors.affiliation: Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg.
authors.forename: P
authors.initials: P
authors.lastname: Albertsson
authors.affiliation: Department of Surgery, University Hospital, Linkoping.
authors.forename: L G
authors.initials: LG
authors.lastname: Arnesson
authors.affiliation: Department of Medicine, Southern Älvsborg Hospital, Borås; Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg.
authors.forename: C
authors.initials: C
authors.lastname: Chamalidou
authors.affiliation: Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg.
authors.forename: Z
authors.initials: Z
authors.lastname: Einbeigi
authors.affiliation: Regional Cancer Center, Gothenburg, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Holmberg
authors.affiliation: Department of Clinical and Experimental Medicine and Department of Oncology, Linköping University, Linköping.
authors.forename: B
authors.initials: B
authors.lastname: Nordenskjöld
authors.affiliation: Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg. Electronic address: per.karlsson@oncology.gu.se.
authors.forename: P
authors.initials: P
authors.lastname: Karlsson
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D002391:Catchment Area, Health; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008327:Mammography; D008408:Mastectomy / Q000009:adverse effects / Q000401:mortality; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D012042:Registries; D012111:Residence Characteristics; D012307:Risk Factors; D016019:Survival Analysis; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome
keywords: breast cancer; positive nodes; postoperative radiotherapy