The ATAC (‘Arimidex’, Tamoxifen, Alone or in Combination) adjuvant breast cancer trial: first results of the endometrial sub-protocol following 2 years of treatment

作者：Simon P. Duffy, Truxton L. Jackson, Mark Lansdown, Kamaira Philips, Michael Wells, S. Pollard, Glen Clack, Michel Coibion, Antonio Bianco · 发表于：Human Reproduction · 年份：2005 · DOI：10.1093/humrep/dei322 · 被引用次数：62 · 研究领域：Estrogen and related hormone effects、Breast Cancer Treatment Studies、Menopause: Health Impacts and Treatments

BACKGROUND: Tamoxifen treatment results in a doubling of the risk of endometrial cancer after 1-2 years of treatment and a quadrupling after 5 years. Anastrozole, a third-generation aromatase inhibitor, with superior efficacy to tamoxifen, may also offer tolerability benefits in terms of effects on the endometrium. METHODS AND RESULTS: A sub-protocol of the ATAC trial compared the incidence/type of intrauterine changes following treatment with these agents in a subgroup of patients (n = 285) from the main trial. After 2 years anastrozole treatment, endometrial thickness remained </= 5 mm (baseline: 3.0 mm); in patients receiving tamoxifen, endometrial thickness increased by 3.2 mm to 7.0 mm, with a similar trend in the combination group. At baseline, 26/285 patients (9.1%) had endometrial abnormalities, most commonly polyps. After 2 years the number of endometrial abnormalities appeared lower with anastrozole treatment compared with tamoxifen although these differences were not statistically significant (odds ratio: 0.44; 95% confidence interval 0.146, 1.314; P = 0.14). Most abnormalities occurred within the first year of treatment (anastrozole: 4/6; tamoxifen: 7/10; combination: 10/16; total: 21/32). Fewer patients in the anastrozole group (1.4%) required medical intervention (tamoxifen 12.5%; combination 13.6%). CONCLUSIONS: Fewer endometrial abnormalities occurred during 2 years treatment with anastrozole compared with tamoxifen although statistical significance was not re...