title: Uterine and quality of life changes in postmenopausal women with an asymptomatic tamoxifen-thickened endometrium randomized to continuation of tamoxifen or switching to anastrozole.
abstract: OBJECTIVE
  Before the knowledge that 5 years of adjuvant tamoxifen is less efficacious than 2 to 3 years of tamoxifen followed by 2 to 3 years of anastrozole/exemestane, we designed a multicenter double-blind randomized controlled trial in women taking tamoxifen with a thickened endometrium to compare uterine and quality-of-life parameters between those switching to anastrozole and those continuing tamoxifen.
  
  
  METHODS
  Asymptomatic postmenopausal women who took adjuvant tamoxifen for 2 to 3 years for operable breast cancer with a double endometrial thickness greater than 7 mm were randomized to 20 mg tamoxifen or 1 mg anastrozole for the remaining duration, totaling 5 years. Tablets were unrecognizable for drug assignment. The primary endpoints were the differences in double endometrial thickness and uterine volume after 1 year. Uterine and quality-of-life data were analyzed using regression methods, and missing values were handled using multiple imputation.
  
  
  RESULTS
  Seventy-two women (median age, 60 y) were randomized in five hospitals. Relative to women continuing tamoxifen, women switching to anastrozole experienced a decrease of 53% (95% CI, 41%-63%) in double endometrial thickness and a decrease of 51% (95% CI, 39%-60%) in uterine volume. Vaginal dryness (b = 0.064; 95% CI, 0.016-0.112) and sexual problems (b = 0.054; 95% CI, 0.007-0.102) increased in women taking anastrozole compared with women taking tamoxifen. Treatment arms did not differ regarding withdrawal rate and the experience of (serious) adverse events.
  
  
  CONCLUSIONS
  Despite premature trial closure, our data provided valuable insights. Switching to anastrozole strongly decreased the endometrial thickness and uterine volume but increased sexual disturbances. Safe and effective interventions are needed to alleviate sexual dysfunction.
authors.affiliation: Department of Electrical Engineering (ESAT-SCD), Katholieke Universiteit Leuven, Leuven, Belgium. ben.vancalster@esat.kuleuven.be
authors.forename: Ben
authors.initials: B
authors.lastname: Van Calster
authors.forename: Johan
authors.initials: J
authors.lastname: Van Ginderachter
authors.forename: Jos
authors.initials: J
authors.lastname: Vlasselaer
authors.forename: Gregg
authors.initials: G
authors.lastname: Van de Putte
authors.forename: Patrick
authors.initials: P
authors.lastname: Berteloot
authors.forename: Dirk
authors.initials: D
authors.lastname: Timmerman
authors.forename: Herman
authors.initials: H
authors.lastname: Depypere
authors.forename: Chantal
authors.initials: C
authors.lastname: Blomme
authors.forename: Geert
authors.initials: G
authors.lastname: Vlaemynck
authors.forename: Eric
authors.initials: E
authors.lastname: De Jonge
authors.forename: Rudy
authors.initials: R
authors.lastname: Van den Broecke
authors.forename: Ignace
authors.initials: I
authors.lastname: Vergote
authors.forename: Frédéric
authors.initials: F
authors.lastname: Amant
authors.forename: Sabine
authors.initials: S
authors.lastname: Van Huffel
authors.forename: Patrick
authors.initials: P
authors.lastname: Neven
mesh_terms: D000368:Aged; D000077384:Anastrozole; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000601:surgery; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008875:Middle Aged; D009570:Nitriles / Q000009:adverse effects / Q000627:therapeutic use*; D017698:Postmenopause / Q000187:drug effects*; D011788:Quality of Life; D012735:Sexual Dysfunction, Physiological / Q000139:chemically induced; D013629:Tamoxifen / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014230:Triazoles / Q000009:adverse effects / Q000627:therapeutic use*; D014599:Uterus / Q000187:drug effects*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077384:Anastrozole