Anastrozole and letrozole: an investigation and comparison of quality of life and tolerability

Dixon, J., Renshaw, L, Langridge, C.I, Young, O., McHugh, M., Williams, L., Murray, J.E, Macaskill, E., McCaig, F., Dixon, O.R and Fallowfield, L.J (2011) Anastrozole and letrozole: an investigation and comparison of quality of life and tolerability. Breast Cancer Research and Treatment, 125 (3). pp. 1-9. ISSN 0167-6806

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Previous studies have demonstrated that both anastrozole and letrozole are well tolerated. Letrozole suppresses estrogen to a greater degree than anastrozole in the serum and breast tumor. Concerns have been raised that greater potency may adversely affect patients’ quality of life (QOL). One hundred eighty-one postmenopausal women with invasive estrogen receptor-positive breast cancers were randomized to receive either 12 weeks of letrozole followed by 12 weeks of anastrozole or the reverse sequence. One hundred and six received immediate adjuvant aromatase inhibitors (AIs) following surgery, and 75 received extended adjuvant therapy. The Functional Assessment of Cancer Therapy Endocrine Subscale (FACT-B-ES) QOL questionnaires were completed to assess QOL on each drug. Additional side-effect profiles were collected. Each patient completed a patient preference form. Twenty-one patients withdrew before study end, 10/179 (5.6%) while taking letrozole and 4/173 (2.3%) while taking anastrozole (P = 0.12). Tamoxifen-naïve patients had a higher mean ES (endocrine symptoms subscale) score at entry versus those having extended therapy (66.0 vs. 61.9; P = 0.001). There was no significant change in FACT-B-ES (overall) scores or ES scores while patients were taking anastrozole or letrozole and no significant differences between drugs. Nearly 80% of patients reported one or more side effects with either agent. No differences in frequency, grade, or range of side effects were seen between drugs. Of 160 patients, 49 (30.6%) preferred letrozole, 57 (35.6%) preferred anastrozole, and 54 (33.8%) had no preference (P = 0.26, Pearson’s Chi-squared test). In conclusion, both AIs are equally well tolerated. There were no significant differences in QOL scores between the two drugs.

Item Type: Article
Additional Information: E-Published 07 September 2010, hard copy February 2011
Keywords: Medicine Anastrozole Breast Cancer Letrozole Quality of Life Tamoxifen
Schools and Departments: Brighton and Sussex Medical School > Sussex Health Outcomes Research & Education in Cancer (SHORE-C)
Subjects: R Medicine > R Medicine (General)
R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology Including cancer and carcinogens
R Medicine > RG Gynecology and obstetrics > RG0491 Diseases of the breast
Depositing User: Tracy Woodcock
Date Deposited: 25 Aug 2011 12:39
Last Modified: 30 Nov 2012 16:55
Google Scholar:1 Citations
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