title: Disease-free survival according to the use of postmastectomy radiation therapy after neoadjuvant chemotherapy.
abstract: BACKGROUND
  The purpose of the study was to determine predictors of recurrence for patients treated with neoadjuvant chemotherapy (NAC) and mastectomy according to the use of postmastectomy radiation therapy (PMRT).
  
  
  METHODS
  An analysis of 161 clinically staged T1 to T3/N0 to N3 patients treated with NAC and mastectomy with and without PMRT at our institution from 2003 to 2010 was conducted. The Kaplan-Meier product limit method was used to estimate survival and time to recurrence rates and the log-rank test was used to compare groups. A Cox proportional hazard regression analysis was carried out for time to recurrence, radiation therapy, and their interaction in the model.
  
  
  RESULTS
  The median follow-up period was 48 months and 18 patients developed a recurrence. The 5-year recurrence rate and overall survival was 16.1% (95% confidence interval [CI], 9.6%-26.3%) and 93.6% (95% CI, 88.2%-97.0%), respectively. Patients who underwent PMRT had a decreased risk of recurrence compared with patients who did not (hazard ratio [HR], 0.25; 95% CI, 0.097-0.661; P < .005). The 5-year disease-free survival (DFS) rate for those who received PMRT was 91.3% (95% CI, 82.8%-95.7%) and 64.8% (95% CI, 37.8%-82.4%) for those who did not (P = .0126). Among all clinicopathologic factors examined, pathologic T stage (ypT) and pathological N stage (ypN) significantly correlated with the risk of recurrence (P < .05). Patients with any pathological nodal disease had an increased risk of recurrence compared with patients who were pathologically node-negative (HR, 7.196; 95% CI, 2.05-25.264; P < .002).
  
  
  CONCLUSIONS
  Patients treated with NAC and mastectomy, but without PMRT had a higher risk recurrence with increasing ypT and ypN stages. PMRT might increase DFS.
authors.affiliation: Department of Radiation Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY. Electronic address: hin9004@nyp.org.
authors.forename: Himanshu
authors.initials: H
authors.lastname: Nagar
authors.affiliation: Department of Radiation Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Dustin
authors.initials: D
authors.lastname: Boothe
authors.affiliation: Department of Pathology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Paula S
authors.initials: PS
authors.lastname: Ginter
authors.affiliation: Department of Biostatistics, the Feinstein Institute for Medical Research, Manhasset, NY.
authors.forename: Cristina
authors.initials: C
authors.lastname: Sison
authors.affiliation: Department of Medical Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Linda
authors.initials: L
authors.lastname: Vahdat
authors.affiliation: Department of Pathology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Sandra
authors.initials: S
authors.lastname: Shin
authors.affiliation: Department of Radiation Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Michael
authors.initials: M
authors.lastname: Smith
authors.affiliation: Department of Radiation Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: K S Clifford
authors.initials: KS
authors.lastname: Chao
authors.affiliation: Department of Radiation Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Dattatreyudu
authors.initials: D
authors.lastname: Nori
authors.affiliation: Department of Radiation Oncology, New York Presbyterian-Hospital/Weill Cornell Medical College, New York, NY.
authors.forename: Mary Katherine
authors.initials: MK
authors.lastname: Hayes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Mastectomy; Neoadjuvant chemotherapy; PMRT