|
|||||
|
|
||||||
JCO Early Release, published online ahead of print Mar 10 2008
Received March 12, 2007 Late Extended Adjuvant Treatment With Letrozole Improves Outcome in Women With Early-Stage Breast Cancer Who Complete 5 Years of Tamoxifen
From the Massachusetts General Hospital Cancer Center, Boston, MA; Mayo Clinic, Rochester, MN; Angeles Clinic and Research Institute, Los Angeles, CA; Inova Fairfax Hospital, Falls Church, VA; University of Vermont, Burlington, VT; Institut Jules Bordet, Brussels, Belgium; International Breast Cancer Study Group Coordinating Center, Bern, Switzerland; National Cancer Institute of Canada, Clinical Trials Group, Kingston, Ontario, Canada; Toronto Sunnybrook Odette Cancer Centre, University of Toronto, Ontario, Canada; University of Washington, Seattle, WA; Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore; Cancer Therapy Evaluation Program, Clinical Investigations Branch, National Cancer Institute, Rockville, MD; Memorial Sloan-Kettering Cancer Center, New York, NY; Mayo Clinic, Jacksonville, FL; and Edinburgh Breast Unit, Western General Hospital, Edinburgh, Scotland. * To whom correspondence should be addressed. E-mail: pgoss{at}partners.org
Purpose: The National Cancer Institute of Canada Clinical Trials Group MA.17 trial examined the efficacy of letrozole (LET) started within 3 months of 5 years of adjuvant tamoxifen in postmenopausal hormone receptor-positive early-stage breast cancer. When the trial was unblinded, patients who received placebo (PLAC) were offered LET. Patients and Methods: This cohort analysis describes the outcomes of women assigned PLAC at the initial random assignment after unblinding. Efficacy outcomes of women who chose LET (PLAC-LET group) were compared with those who did not (PLAC-PLAC group) by the hazard ratios and by P values calculated from Cox models that adjusted for imbalances between the groups. Toxicity analyses included only events that occurred after unblinding. Results: There were 1,579 women in the PLAC-LET group (median time from tamoxifen, 2.8 years) and 804 in the PLAC-PLAC group. Patients in the PLAC-LET group were younger; had a better performance status; and were more likely to have had node-positive disease, axillary dissection, and adjuvant chemotherapy than those in the PLAC-PLAC group. At a median follow-up of 5.3 years, disease-free survival (DFS; adjusted hazard ratio [HR], 0.37; 95% CI, 0.23 to 0.61; P <.0001) and distant DFS (HR, 0.39; 95% CI, 0.20 to 0.74; P = .004) were superior in the PLAC-LET group. More self-reported new diagnoses of osteoporosis and significantly more clinical fractures occurred in the women who took LET (5.2% v 3.1%, P = .02). Conclusion: Interpretation of this cohort analysis suggests that LET improves DFS and distant DFS even when there has been a substantial period of time since the discontinuation of prior adjuvant tamoxifen.
Related Articles
Related Editorial
Related Correspondence
This article has been cited by other articles:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||
|
Copyright © 2008 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|