title: Identifying breast cancer patients most likely to benefit from aromatase inhibitor therapy after adjuvant radiation and tamoxifen.
abstract: BACKGROUND
  The purpose of the current study was to examine patient selection for an aromatase inhibitor in breast cancer patients who were free from adverse events 5 years after treatment with tamoxifen.
  
  
  METHODS
  In all, 471 women were treated with breast-conserving surgery, axillary lymph node dissection, and radiation. Eligibility included T1-2 disease, tamoxifen use, follow-up of >/=5 years, no prior breast cancer, and freedom from all events at 5 years of follow-up. Patients treated with chemotherapy more often had T2 disease and positive lymph nodes, and were aged <60 years compared with patients treated with tamoxifen alone. No patient during the period of the current study (1982-1999) received an aromatase inhibitor. The median follow-up was 8.25 years.
  
  
  RESULTS
  There were 36 events: 10 contralateral breast cancers (CBCs) and 26 recurrences (8 local, 1 regional, and 17 distant). The 10-year risk of locoregional recurrence was 2.5%, the 10-year risk of CBC was 3.6%, and the 10-year risk of distant metastasis was 4.4%. The event-free survival rate for all patients was 93%. Only >/=4 positive lymph nodes and premenopausal status were found to be independent variables for decreased event-free survival on multivariate analysis. The overall survival rate was 89%. Only younger age and lower lymph node status were found to be significant predictors of improved overall survival.
  
  
  CONCLUSIONS
  In the current study, a 40% reduction in recurrence/CBC with the addition of an aromatase inhibitor after 5 years of tamoxifen treatment would have had a marginal benefit of 1% to 2%. Women who were premenopausal and patients with >/=4 positive lymph nodes would have the greatest absolute benefit of >3% in the 10-year event-free survival rate from extended therapy. The decision needs to be individualized for patients aged >/=60 years based on their initial lymph node status and the presence of comorbidities that could lower their 5-year life expectancy.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA. Gary.Freedman@FCCC.edu
authors.forename: Gary M
authors.initials: GM
authors.lastname: Freedman
authors.forename: Penny
authors.initials: P
authors.lastname: Anderson
authors.forename: Tianyu
authors.initials: T
authors.lastname: Li
authors.forename: Eric
authors.initials: E
authors.lastname: Ross
authors.forename: Ramona
authors.initials: R
authors.lastname: Swaby
authors.forename: Lori
authors.initials: L
authors.lastname: Goldstein
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000532:radiotherapy / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis; D015996:Survival Rate; D013629:Tamoxifen / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D047072:Aromatase Inhibitors; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen