|
KMID : 1134120210240020164
|
|
Journal of Breast Cancer
2021 Volume.24 No. 2 p.164 ~ p.174
|
|
|
Clinical Outcomes Following Letrozole Treatment according to Estrogen Receptor Expression in Postmenopausal Women: LETTER Study (KBCSG-006)
|
|
Ahn Sung-Gwe
Nam Seok-Jin
Ahn Sei-Hyun
Jung Yong-Sik
Park Heung-Kyu
Lee Soo-Jung
Kang Sung-Soo
Han Won-Shik
Park Kyong-Hwa
Park Yong-Lai
Lee Ji-Hyoun
Youn Hyun-Jo
Kim Jun-Hyun
Yoo Young-Bum
Song Jeong-Yoon
Ko Byung-Kyun
Gwak Geum-Hee
Chung Min-Sung
Kim Sung-Yong
Cho Seo-Heon
Kim Do-Yil
Chang Myung-Chul
Moon Byung-In
Kim Lee-Su
Kim Sei-Joong
Park Min-Ho
Kim Tae-Hyun
Cho Ji-Hyoung
Lim Cheol-Wan
Bae Young-Tae
Gong Gyung-Yub
Bae Young-Kyung
Lee Ah-Won
Jeong Joon
|
|
|
Abstract
|
|
|
Purpose: In this trial, we investigated the efficacy and safety of adjuvant letrozole for hormone receptor (HR)-positive breast cancer. Here, we report the clinical outcome in postmenopausal women with HR-positive breast cancer treated with adjuvant letrozole according to estrogen receptor (ER) expression levels.
Methods: In this multi-institutional, open-label, observational study, postmenopausal patients with HR-positive breast cancer received adjuvant letrozole (2.5 mg/daily) for 5 years unless they experienced disease progression or unacceptable toxicity or withdrew their consent. The patients were stratified into the following 3 groups according to ER expression levels using a modified Allred score (AS): low, intermediate, and high (AS 3?4, 5?6, and 7?8, respectively). ER expression was centrally reviewed. The primary objective was the 5-year disease-free survival (DFS) rate.
Results: Between April 25, 2010, and February 5, 2014, 440 patients were enrolled. With a median follow-up of 62.0 months, the 5-year DFS rate in all patients was 94.2% (95% confidence interval [CI], 91.8?96.6). The 5-year DFS and recurrence-free survival (RFS) rates did not differ according to ER expression; the 5-year DFS rates were 94.3% and 94.1%in the low-to-intermediate and high expression groups, respectively (p = 0.6), and the corresponding 5-year RFS rates were 95.7% and 95.4%, respectively (p = 0.7). Furthermore, 25 patients discontinued letrozole because of drug toxicity.
Conclusion: Treatment with adjuvant letrozole showed very favorable treatment outcomes and good tolerability among Korean postmenopausal women with ER-positive breast cancer, independent of ER expression.
|
|
|
KEYWORD
|
|
|
Breast neoplasms, Letrozole, Postmenopause, Receptors, estrogen
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
   
|
|