title: National Trends in the Use of Neoadjuvant Chemotherapy for Hormone Receptor-Negative Breast Cancer: A National Cancer Data Base Study.
abstract: BACKGROUND
  Neoadjuvant chemotherapy (NAC) downstages tumor size and nodal disease. This study evaluates national practice patterns of NAC use in hormone receptor-negative breast cancer.
  
  
  METHODS
  We identified patients in the National Cancer Data Base (NCDB) with hormone receptor-negative invasive breast cancer (2004-2012). Univariate and multivariable logistic regression was used to assess associations and trends across time.
  
  
  RESULTS
  Of 171,985 patients, 130,723 (76.0%) received chemotherapy and 41,262 (24.0%) did not. Chemotherapy use was higher in young patients and higher T- and N-stage disease (all p < 0.001). Of those patients treated with chemotherapy, 23,165 (17.7%) received NAC and 107,558 (82.3%) received adjuvant chemotherapy (AC). NAC use increased from 2004 to 2012 (13.0-23.5%; adjusted odds ratio [aOR] 1.42; p < 0.001). Higher clinical T stage (ORs 3.63, 11.81, and 22.34 for cT2, cT3, and cT4a-c, respectively, vs. cT1) and cN+ disease (OR 2.86) [each p < 0.001] were associated with NAC, as were younger patient age and better Charlson-Deyo comorbidity score. Furthermore, BCS rate was higher in the NAC group in cT2 and cT3 tumors (aOR 1.17 and 1.45, respectively; both p < 0.001). In patients with cN+ disease, NAC converted 43.7% to pN0. Less extensive axillary surgery (one to five nodes removed) was more likely in cN+ patients treated with NAC (aOR 1.66; p < 0.001).
  
  
  CONCLUSIONS
  In hormone receptor-negative breast cancer, chemotherapy was mostly administered adjuvantly, but neoadjuvant use increased over time and was more likely in younger patients and higher T- and N-stage disease. Node-positive patients treated with NAC were less likely to have pathologically positive nodes and more likely to have less extensive axillary surgery.
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN, 55905, USA.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Puig
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Hoskin
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Courtney N
authors.initials: CN
authors.lastname: Day
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN, 55905, USA.|Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.|Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Habermann
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN, 55905, USA. boughey.judy@mayo.edu.
authors.forename: Judy C
authors.initials: JC
authors.lastname: Boughey
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001365:Axilla; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000628:therapy*; D018567:Breast Neoplasms, Male / Q000737:chemistry / Q000473:pathology / Q000628:therapy; D017024:Chemotherapy, Adjuvant / Q000639:trends; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000706:statistics & numerical data; D008297:Male; D015412:Mastectomy, Segmental / Q000639:trends; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000639:trends*; D009367:Neoplasm Staging; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D012189:Retrospective Studies; D014481:United States
chemical_list: D000970:Antineoplastic Agents; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone