title: Outcomes of low-risk ductal carcinoma in situ in Southeast Asian women treated with breast conservation therapy.
abstract: OBJECTIVE
  To examine the outcomes of Southeast Asian (SEA) women with low-risk ductal carcinoma in situ (DCIS) treated with breast-conserving surgery (BCS) and adjuvant radiation therapy.
  
  
  METHODS
  Retrospective chart reviews of patients treated with BCS for DCIS from 1995 to 2011 were performed. Patients meeting the selection criteria from Eastern Cooperative Oncology Group 5194 were included. Most patients received adjuvant radiation therapy (RT) consisting of whole-breast RT delivered to 50 Gy followed by a 10-Gy boost to the tumor bed.
  
  
  RESULTS
  Of 744 patients with pathologic diagnosis of pure DCIS identified, 273 met the selection criteria: low-intermediate grade (LIG), n=219; high grade (HG), n=54. Median follow-up for these patients was 60 months. There were 8 ipsilateral breast tumor recurrences (IBTRs) in total, 7 of which were DCIS. The estimated actuarial IBTR rates at 5 and 10 years for the entire cohort are 1.8% and 4.3%, respectively. Of the 219 patients with LIG DCIS, 210 received RT and 9 did not. There were 7 IBTRs in LIG DCIS, 2 among the 9 patients who did not receive RT. The IBTR rates in LIG DCIS at 5 and 10 years are 2.3% and 4.2%, respectively. All patients with HG DCIS received RT. There was only 1 IBTR occurring beyond 5 years, giving an estimated IBTR rate of 4.5% at 10 years.
  
  
  CONCLUSIONS
  SEA women with screen-detected DCIS have exceedingly low rates of IBTR after BCS, comparable to that observed in reports of similar patients with low-risk DCIS treated with adjuvant radiation.
authors.affiliation: Department of Radiation Oncology, National Cancer Centre Singapore, Singapore. Electronic address: fuhyong@yahoo.com.
authors.forename: Fuh Yong
authors.initials: FY
authors.lastname: Wong
authors.affiliation: Department of Radiation Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Cancer Informatics, National Cancer Centre Singapore, Singapore.
authors.forename: John Ju
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Chiew Har
authors.initials: CH
authors.lastname: Tan
authors.affiliation: Department of Pathology, Singapore General Hospital, Singapore.
authors.forename: Puay Hoon
authors.initials: PH
authors.lastname: Tan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001210:Asia, Southeastern; D001940:Breast / Q000601:surgery*; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000532:radiotherapy* / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012189:Retrospective Studies; D012306:Risk; D012846:Singapore; D016896:Treatment Outcome