Title: The advantage of letrozole over tamoxifen in the BIG 1-98 trial is consistent in younger postmenopausal women and in those with chemotherapy-induced menopause
Authors: Chirgwin, Jacquie ×
Sun, Zhuoxin
Smith, Ian
Price, Karen N
Thürlimann, Beat
Ejlertsen, Bent
Bonnefoi, Hervé
Regan, Meredith M
Goldhirsch, Aron
Coates, Alan S
BIG 1-98 Collaborative and International Breast Cancer Study Groups
Contributors: Paridaens, Robert
Issue Date: Jan-2012
Publisher: M. Nijhoff
Series Title: Breast Cancer Research and Treatment vol:131 issue:1 pages:295-306
Abstract: Letrozole, an aromatase inhibitor, is ineffective in the presence of ovarian estrogen production. Two subpopulations of apparently postmenopausal women might derive reduced benefit from letrozole due to residual or returning ovarian activity: younger women (who have the potential for residual subclinical ovarian estrogen production), and those with chemotherapy-induced menopause who may experience return of ovarian function. In these situations tamoxifen may be preferable to an aromatase inhibitor. Among 4,922 patients allocated to the monotherapy arms (5 years of letrozole or tamoxifen) in the BIG 1-98 trial we identified two relevant subpopulations: patients with potential residual ovarian function, defined as having natural menopause, treated without adjuvant or neoadjuvant chemotherapy and age ≤ 55 years (n = 641); and those with chemotherapy-induced menopause (n = 105). Neither of the subpopulations examined showed treatment effects differing from the trial population as a whole (interaction P values are 0.23 and 0.62, respectively). Indeed, both among the 641 patients aged ≤ 55 years with natural menopause and no chemotherapy (HR 0.77 [0.51, 1.16]) and among the 105 patients with chemotherapy-induced menopause (HR 0.51 [0.19, 1.39]), the disease-free survival (DFS) point estimate favoring letrozole was marginally more beneficial than in the trial as a whole (HR 0.84 [0.74, 0.95]). Contrary to our initial concern, DFS results for young postmenopausal patients who did not receive chemotherapy and patients with chemotherapy-induced menopause parallel the letrozole benefit seen in the BIG 1-98 population as a whole. These data support the use of letrozole even in such patients.
ISSN: 0167-6806
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Laboratory of Experimental Oncology
× corresponding author

Files in This Item:

There are no files associated with this item.

Request a copy


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science