title: Impact on survival of time from definitive surgery to initiation of adjuvant chemotherapy for early-stage breast cancer.
abstract: OBJECTIVE
  To determine if time to start of adjuvant chemotherapy after curative surgery influences survival in early-stage breast cancer.
  
  
  METHODS
  A retrospective review was conducted of 2,594 patients receiving adjuvant chemotherapy for stage I and II breast cancer between 1989 and 1998 at the British Columbia Cancer Agency. Relapse-free survival (RFS) and overall survival (OS) were compared among patients grouped by time from definitive curative surgery to start of adjuvant chemotherapy (< or = 4 weeks, > 4 to 8 weeks, > 8 to 12 weeks, and >12 to 24 weeks).
  
  
  RESULTS
  RFS and OS were similar for women starting chemotherapy up to 12 weeks after surgery. OS hazard ratio (univariate) for initiation of chemotherapy more than 12 weeks compared with 12 weeks or less after surgery was 1.5 (95% CI, 1.07 to 2.10; P = .017). Five-year OS rates were 84%, 85%, 89%, and 78%, (log-rank P = .013); RFS rates were 74%, 79%, 82%, and 69% (log-rank P = .004) for patients starting chemotherapy 4 weeks or fewer, more than 4 to 8 weeks, more than 8 to 12 weeks, and more than 12 to 24 weeks after surgery, respectively. In multivariate analysis, independent prognostic factors were grade, size, nodal status, estrogen receptor, age, and lymphatic and/or vascular invasion. Initiation of adjuvant chemotherapy more than 12 weeks from surgery remained significantly associated with inferior survival, with a hazard ratio of 1.6 (95% CI, 1.2 to 2.3; P = .005).
  
  
  CONCLUSIONS
  This retrospective analysis suggests that adjuvant chemotherapy is equally effective up to 12 weeks after definitive surgery but that RFS and OS appear to be compromised by delays of more than 12 weeks after definitive surgery.
authors.affiliation: Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver. clohrisch@bccancer.bc.ca
authors.forename: Caroline
authors.initials: C
authors.lastname: Lohrisch
authors.forename: Charles
authors.initials: C
authors.lastname: Paltiel
authors.forename: Karen
authors.initials: K
authors.lastname: Gelmon
authors.forename: Caroline
authors.initials: C
authors.lastname: Speers
authors.forename: Suzanne
authors.initials: S
authors.lastname: Taylor
authors.forename: Jeff
authors.initials: J
authors.lastname: Barnett
authors.forename: Ivo A
authors.initials: IA
authors.lastname: Olivotto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome