title: Boost radiotherapy in young women with ductal carcinoma in situ: a multicentre, retrospective study of the Rare Cancer Network.
abstract: BACKGROUND
  Outcome data in young women with ductal carcinoma in situ (DCIS) are rare. The benefits of boost radiotherapy in this group are also unknown. We aimed to assess the effect of boost radiotherapy in young patients with DCIS.
  
  
  METHODS
  We included 373 women from 18 institutions who met the following inclusion criteria: having tumour status Tis and nodal status (N)0, age 45 years or younger at diagnosis, and having had breast-conserving surgery. 57 (15%) patients had no radiotherapy after surgery, 166 (45%) had radiotherapy without boost (median dose 50 Gy [range 40-60]), and 150 (40%) had radiotherapy with boost (60 Gy [53-76]). The primary outcome was local relapse-free survival.
  
  
  RESULTS
  Median follow-up was 72 months (range 1-281). 55 (15%) patients had local relapse. Local relapse-free survival at 10 years was 46% (95% CI 24-67) for patients given no radiotherapy, 72% (61-83) for those given radiotherapy without boost, and 86% (78-93) for those given radiotherapy and boost (difference between all three groups, p<0.0001). Age, margin status, and radiotherapy dose were significant predictors of local relapse-free survival. Compared with patients who had no radiotherapy, those who had radiotherapy had a decreased risk of local relapse (without boost, hazard ratio 0.33 [95% CI 0.16-0.71], p=0.004; with boost, 0.15 [0.06-0.36], p<0.0001).
  
  
  CONCLUSIONS
  In the absence of randomised trials, boost radiotherapy should be considered in addition to surgery for breast-conserving treatment for DCIS.
authors.affiliation: Department of Radiation Oncology, University of Bern, Inselspital, Bern, Switzerland.
authors.forename: Aurelius
authors.initials: A
authors.lastname: Omlin
authors.forename: Maurizio
authors.initials: M
authors.lastname: Amichetti
authors.forename: David
authors.initials: D
authors.lastname: Azria
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Cole
authors.forename: Philippe
authors.initials: P
authors.lastname: Fourneret
authors.forename: Philip
authors.initials: P
authors.lastname: Poortmans
authors.forename: Diana
authors.initials: D
authors.lastname: Naehrig
authors.forename: Robert C
authors.initials: RC
authors.lastname: Miller
authors.forename: Marco
authors.initials: M
authors.lastname: Krengli
authors.forename: Cristina
authors.initials: C
authors.lastname: Gutierrez Miguelez
authors.forename: David
authors.initials: D
authors.lastname: Morgan
authors.forename: Hadassah
authors.initials: H
authors.lastname: Goldberg
authors.forename: Luciano
authors.initials: L
authors.lastname: Scandolaro
authors.forename: Pauline
authors.initials: P
authors.lastname: Gastelblum
authors.forename: Mahmut
authors.initials: M
authors.lastname: Ozsahin
authors.forename: Dagmar
authors.initials: D
authors.lastname: Dohr
authors.forename: David
authors.initials: D
authors.lastname: Christie
authors.forename: Ulrich
authors.initials: U
authors.lastname: Oppitz
authors.forename: Ufuk
authors.initials: U
authors.lastname: Abacioglu
authors.forename: Guenther
authors.initials: G
authors.lastname: Gruber
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000517:prevention & control; D008408:Mastectomy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D011879:Radiotherapy Dosage; D012189:Retrospective Studies