Clinical Outcomes Following Letrozole Treatment according to Estrogen Receptor Expression in Postmenopausal Women: LETTER Study (KBCSG-006)
- Authors
- Ahn, SG[Ahn, Sung Gwe]; Nam, SJ[Nam, Seok Jin]; Ahn, SH[Ahn, Sei Hyun]; Jung, YS[Jung, Yongsik]; Park, HK[Park, Heung Kyu]; Lee, SJ[Lee, Soo Jung]; Kang, SS[Kang, Sung Soo]; Han, WS[Han, Wonshik]; Park, KH[Park, Kyong Hwa]; Park, YL[Park, Yong Lai]; Lee, J[Lee, Jihyoun]; Youn, HJ[Youn, Hyun Jo]; Kim, JH[Kim, Jun Hyun]; Yoo, Y[Yoo, Youngbum]; Song, JY[Song, Jeong Yoon]; Ko, BK[Ko, Byung Kyun]; Gwak, G[Gwak, Geumhee]; Chung, MS[Chung, Min Sung]; Kim, SY[Kim, Sung Yong]; Cho, SH[Cho, Seo Heon]; Kim, D[Kim, Doyil]; Chang, MC[Chang, Myung Chul]; Moon, BI[Moon, Byung In]; Kim, LS[Kim, Lee Su]; Kim, SJ[Kim, Sei Joong]; Park, MH[Park, Min Ho]; Kim, TH[Kim, Tae Hyun]; Cho, J[Cho, Jihyoung]; Lim, CW[Lim, Cheol Wan]; Bae, YT[Bae, Young Tae]; Gong, G[Gong, Gyungyub]; Bae, YK[Bae, Young Kyung]; Lee, A[Lee, Ahwon]; Jeong, J[Jeong, Joon]
- Issue Date
- Apr-2021
- Publisher
- KOREAN BREAST CANCER SOC
- Keywords
- Breast neoplasms; Letrozole; Postmenopause; Receptors, estrogen
- Citation
- JOURNAL OF BREAST CANCER, v.24, no.2, pp.164 - 174
- Indexed
- SCIE
SCOPUS
KCI
- Journal Title
- JOURNAL OF BREAST CANCER
- Volume
- 24
- Number
- 2
- Start Page
- 164
- End Page
- 174
- URI
- https://scholarworks.bwise.kr/skku/handle/2021.sw.skku/1264
- DOI
- 10.4048/jbc.2021.24.e17
- ISSN
- 1738-6756
- 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.
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Collections - Medicine > Department of Medicine > 1. Journal Articles
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