HOMEPRODUCTSSERVICESCOMPANYCONTACTFAQResearchDictionaryPharmaMobileSign Up FREE or Login

Letrozole in the extended adjuvant setting: MA.17.

Abstract
Relapse after completing adjuvant tamoxifen therapy is a persistent threat for women with hormone-responsive breast cancer. Third-generation aromatase inhibitors, such as letrozole, provide a new option for extended adjuvant hormonal therapy after 5 years of tamoxifen. MA.17 was conducted to determine whether letrozole improves outcome after discontinuation of tamoxifen. Postmenopausal women with hormone receptor-positive breast cancer (N=5,187) were randomized to letrozole 2.5 mg or placebo once daily for 5 years. At a median follow-up of 30 months, letrozole significantly improved disease-free survival (DFS; P<0.001), the primary end point, compared with placebo (hazard ratio [HR] for recurrence or contralateral breast cancer 0.58; 95% confidence interval [CI] 0.45, 0.76] P<0.001). Furthermore, letrozole significantly improved distant DFS (HR=0.60; 95% CI 0.43, 0.84; P=0.002) and, in women with node-positive tumors, overall survival (HR=0.61; 95% CI 0.38, 0.98; P=0.04). Clinical benefits, including an overall survival advantage, were also seen in women who crossed over from placebo to letrozole after unblinding, indicating that tumors remain sensitive to hormone therapy despite a prolonged period since discontinuation of tamoxifen. The efficacy and safety of letrozole therapy beyond 5 years is being assessed in a re-randomization study, following the emergence of new data suggesting that clinical benefit correlates with the duration of letrozole. MA.17 showed that letrozole is extremely well-tolerated relative to placebo. Letrozole should be considered for all women completing tamoxifen; new results from the post-unblinding analysis suggest that letrozole treatment should also be considered for all disease-free women for periods up to 5 years following completion of adjuvant tamoxifen.
AuthorsPaul E Goss
JournalBreast cancer research and treatment (Breast Cancer Res Treat) Vol. 105 Suppl 1 Pg. 45-53 ( 2007) ISSN: 0167-6806 [Print] Netherlands
PMID17912635 (Publication Type: Journal Article, Randomized Controlled Trial)
Chemical References
  • Antineoplastic Agents, Hormonal
  • Aromatase Inhibitors
  • Nitriles
  • Receptors, Estrogen
  • Triazoles
  • Tamoxifen
  • letrozole
Topics
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents, Hormonal (administration & dosage)
  • Aromatase Inhibitors (administration & dosage)
  • Breast Neoplasms (drug therapy, mortality)
  • Chemotherapy, Adjuvant
  • Cross-Over Studies
  • Disease-Free Survival
  • Drug Administration Schedule
  • Female
  • Humans
  • Middle Aged
  • Neoplasm Recurrence, Local (prevention & control)
  • Neoplasms, Hormone-Dependent (drug therapy, mortality)
  • Nitriles (administration & dosage)
  • Quality of Life
  • Receptors, Estrogen (drug effects)
  • Tamoxifen (administration & dosage)
  • Treatment Outcome
  • Triazoles (administration & dosage)

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research network!


Choose Username:
Email:
Password:
Verify Password: