title: Postmastectomy radiation improves the outcome of patients with locally advanced breast cancer who achieve a pathologic complete response to neoadjuvant chemotherapy.
abstract: OBJECTIVE
  The aim of this study was to investigate the role of postmastectomy radiation therapy in women with breast cancer who achieved a pathologic complete response (pCR) to neoadjuvant chemotherapy.
  
  
  METHODS
  We retrospectively identified 226 patients treated at our institution who achieved a pCR at surgery after receiving neoadjuvant chemotherapy. Of these, the 106 patients without inflammatory breast cancer who were treated with mastectomy were analyzed. The patients' clinical stages at diagnosis were I in 2%, II in 31%, IIIA in 30%, IIIB in 25%, and IIIC in 11% (American Joint Committee on Cancer 2003 system). Of the patients, 92% received anthracycline-based chemotherapy, and 38% also received a taxane. A total of 72 patients received postmastectomy radiation therapy, and 34 did not. The actuarial rates of local-regional recurrence (LRR) and survival of the two groups were compared using the log-rank test.
  
  
  RESULTS
  The median follow-up of surviving patients was 62 months. Use of radiation therapy did not affect the 10-year rates of LRR for patients with Stage I or II disease (the 10-year LRR rates were 0% for both groups). However, the 10-year LRR rate for patients with Stage III disease was significantly improved with radiation therapy (7.3% +/- 3.5% with vs. 33.3% +/- 15.7% without; p = 0.040). Within this cohort, use of radiation therapy was also associated with improved disease-specific and overall survival.
  
  
  CONCLUSIONS
  Postmastectomy radiation therapy provides a significant clinical benefit for breast cancer patients who present with clinical Stage III disease and achieve a pCR after neoadjuvant chemotherapy.
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
authors.forename: Sean E
authors.initials: SE
authors.lastname: McGuire
authors.forename: Ana M
authors.initials: AM
authors.lastname: Gonzalez-Angulo
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Huang
authors.forename: Susan L
authors.initials: SL
authors.lastname: Tucker
authors.forename: Shu-Wan C
authors.initials: SW
authors.lastname: Kau
authors.forename: Tse-Kuan
authors.initials: TK
authors.lastname: Yu
authors.forename: Eric A
authors.initials: EA
authors.lastname: Strom
authors.forename: Julia L
authors.initials: JL
authors.lastname: Oh
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Woodward
authors.forename: Welela
authors.initials: W
authors.lastname: Tereffe
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Hunt
authors.forename: Henry M
authors.initials: HM
authors.lastname: Kuerer
authors.forename: Aysegul A
authors.initials: AA
authors.lastname: Sahin
authors.forename: Gabriel N
authors.initials: GN
authors.lastname: Hortobagyi
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Buchholz
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents