title: Randomized trial of breast irradiation schedules after lumpectomy for women with lymph node-negative breast cancer.
abstract: BACKGROUND
  Breast irradiation after lumpectomy is an integral component of breast-conserving therapy that reduces the local recurrence of breast cancer. Because an optimal fractionation schedule (radiation dose given in a specified number of fractions or treatment sessions over a defined time) for breast irradiation has not been uniformly accepted, we examined whether a 22-day fractionation schedule was as effective as the more traditional 35-day schedule in reducing recurrence.
  
  
  METHODS
  Women with invasive breast cancer who were treated by lumpectomy and had pathologically clear resection margins and negative axillary lymph nodes were randomly assigned to receive whole breast irradiation of 42.5 Gy in 16 fractions over 22 days (short arm) or whole breast irradiation of 50 Gy in 25 fractions over 35 days (long arm). The primary outcome was local recurrence of invasive breast cancer in the treated breast. Secondary outcomes included cosmetic outcome, assessed with the European Organisation for Research and Treatment of Cancer (EORTC) Cosmetic Rating System. All statistical tests were two-sided.
  
  
  RESULTS
  From April 1993 through September 1996, 1234 women were randomly assigned to treatment, 622 to the short arm and 612 to the long arm. Median follow-up was 69 months. Five-year local recurrence-free survival was 97.2% in the short arm and 96.8% in the long arm (absolute difference = 0.4%, 95% confidence interval [CI] = -1.5% to 2.4%). No difference in disease-free or overall survival rates was detected between study arms. The percentage of patients with an excellent or good global cosmetic outcome at 3 years was 76.8% in the short arm and 77.0% in the long arm; the corresponding data at 5 years were 76.8% and 77.4%, respectively (absolute difference = -0.6%, 95% CI = -6.5% to 5.5%).
  
  
  CONCLUSIONS
  The more convenient 22-day fractionation schedule appears to be an acceptable alternative to the 35-day schedule.
authors.affiliation: T. Whelan, M. Levine, McMaster University, and Cancer Care Ontario (CCO) Hamilton Regional Cancer Centre, Hamilton, Ontario, Canada. tim.whelan@hrcc.on.ca
authors.forename: Timothy
authors.initials: T
authors.lastname: Whelan
authors.forename: Robert
authors.initials: R
authors.lastname: MacKenzie
authors.forename: Jim
authors.initials: J
authors.lastname: Julian
authors.forename: Mark
authors.initials: M
authors.lastname: Levine
authors.forename: Wendy
authors.initials: W
authors.lastname: Shelley
authors.forename: Laval
authors.initials: L
authors.lastname: Grimard
authors.forename: Barbara
authors.initials: B
authors.lastname: Lada
authors.forename: Himu
authors.initials: H
authors.lastname: Lukka
authors.forename: Francisco
authors.initials: F
authors.lastname: Perera
authors.forename: Anthony
authors.initials: A
authors.lastname: Fyles
authors.forename: Ethan
authors.initials: E
authors.lastname: Laukkanen
authors.forename: Sunil
authors.initials: S
authors.lastname: Gulavita
authors.forename: Veronique
authors.initials: V
authors.lastname: Benk
authors.forename: Barbara
authors.initials: B
authors.lastname: Szechtman
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D003358:Cosmetics; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011878:Radiotherapy / Q000009:adverse effects
chemical_list: D003358:Cosmetics