Efficacy of Letrozole as First-Line Treatment of Postmenopausal Women with Hormone Receptor–Positive Metastatic Breast Cancer in Korea.
- Author:
Seung Hoon BEOM
1
;
Jisu OH
;
Tae Yong KIM
;
Kyung Hun LEE
;
Yaewon YANG
;
Koung Jin SUH
;
Hyeong Gon MOON
;
Sae Won HAN
;
Do Youn OH
;
Wonshik HAN
;
Tae You KIM
;
Dong Young NOH
;
Seock Ah IM
Author Information
- Publication Type:Original Article
- Keywords: Letrozole; Hormone receptor-positive; Metastatic breast cancer; First-line treatment; Korea
- MeSH: Administration, Oral; Breast Neoplasms*; Breast*; Disease Progression; Disease-Free Survival; Female; Humans; Korea*; Multivariate Analysis; Retrospective Studies
- From:Cancer Research and Treatment 2017;49(2):454-463
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: Letrozole showed efficacy and generally favorable toxicities, along with the convenience of oral administration in postmenopausal patients with hormone receptor (HR)–positive metastatic breast cancer (MBC). To the best of our knowledge, there have been no reports of the clinical outcomes in Korean patients, although letrozole is widely used in practice. Therefore, this studywas conducted to affirm the efficacy and toxicities of letrozole in Korean patients. MATERIALS AND METHODS: This study retrospectively analyzed 84 HR-positive MBC patients who had been treated with letrozole from January 2001 to December 2012. Clinicopathological characteristics and treatment history were extracted from medicalrecords. All patients received 2.5 mg letrozole once a day until there were disease progressions or unacceptable toxicity. Progression-free survival (PFS) was the primary endpoint, and secondary endpoints were overall survival (OS), objective response rate (ORR), and toxicity. RESULTS: The median age of the subjects was 59.3 years. Letrozole treatment resulted in a median PFS of 16.8 months (95% confidence interval [CI], 9.8 to 23.8) and a median OS of 56.4 months (95% CI, 38.1 to 74.7). The ORR was 36.9% for the 84 patients with measurable lesions. Multivariate analysis revealed symptomatic visceral disease (hazard ratio, 3.437; 95% CI, 1.576 to 7.495; p=0.002) and a disease-free interval ≤ 2 years (hazard ratio, 2.697; 95% CI, 1.262 to 5.762; p=0.010) were independently associated with shorter PFS. However, sensitivity to adjuvant hormone treatment was not related to PFS. Letrozole was generally well tolerated. CONCLUSION: Letrozole showed considerable efficacy and tolerability as a first-line treatment in postmenopausal patients with HR-positive MBC.
