title: The Effect of Molecular Subtype and Residual Disease on Locoregional Recurrence in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy and Postmastectomy Radiation.
abstract: BACKGROUND
  The relative contribution of biologic subtype to locoregional recurrence (LRR) in patients treated with neoadjuvant chemotherapy (NAC), mastectomy, and postmastectomy radiotherapy (PMRT) is not clearly defined.
  
  
  METHODS
  233 patients with stages 2 and 3 breast cancer who received NAC, mastectomy, and PMRT between 2000 and 2009 were included: 53 % (n = 123) had HR+ (ER or PR+/HER2-), 23 % (n = 53) had HER2+ (HER2+/HR+ or HR-), and 24 % (n = 57) had triple-negative (TN) disease (HR-/HER2-). The 5-year LRR rates were estimated by Kaplan-Meier methods. Cox regression analysis was performed to evaluate covariates associated with LRR.
  
  
  RESULTS
  The median follow-up period was 62 months. A pathologic complete response (pCR) was seen in 14 % of the patients. The 5-year LRR rate was 8 % for the entire cohort. The LRR rate was 0 % for the patients with a pCR versus 9 % for the patients without a pCR (p = 0.05). TN disease [Hazard ratio (HR) 4.4; p = 0.003] and pathologic node positivity (HR 9.8; p = 0.03) were associated with LRR. Patients with TN disease had a higher LRR rate than patients with HER2+ or HR+ disease (20 vs. 6 and 4 %; p = 0.005). Among patients without a pCR, TN subtype was associated with increased LRR risk (26 versus 7 % HER+ and 4 % HR+; p < 0.001).
  
  
  CONCLUSIONS
  Patients with TN breast cancer had the highest LRR rate after NAC, mastectomy and PMRT. Whereas no LRR was observed among TN patients with a pCR, TN patients with residual disease had a significantly higher LRR risk. Patients with HR+ and HER2+ breast cancer had favorable LRR rates regardless of NAC response, likely due to receipt of adjuvant systemic targeted therapies.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: T Jonathan
authors.initials: TJ
authors.lastname: Yang
authors.affiliation: Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Morrow
authors.affiliation: Breast Oncology Service, Department of Medical Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Shanu
authors.initials: S
authors.lastname: Modi
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Kate
authors.initials: K
authors.lastname: Krause
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Chun
authors.initials: C
authors.lastname: Siu
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Beryl
authors.initials: B
authors.lastname: McCormick
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Simon N
authors.initials: SN
authors.lastname: Powell
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA. hoa1234@mskcc.org.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Ho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D018275:Carcinoma, Lobular / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008197:Lymph Node Excision; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human