( Anastrozole (ArimidexTM) improves over...)First single breast cancer study to show significant survival,benefit for women switching from tamoxifen to Arimidex,Health

Anastrozole (ArimidexTM) improves overall survival in postmenopausal women with early breast cancer receiving treatment with tamoxifen

– Survival benefit demonstrated for an AI over tamoxifen in a single trial –

LUTON, England, Friday 15 June 2007: Analysis of the entire population of a single trial has demonstrated that survival in early breast cancer can be significantly improved by switching from tamoxifen to anastrozole (ArimidexTM). An analysis of the ‘Arimidex’-‘Nolvadex’ 95 (ARNO 95) study, published online in The Journal of Clinical Oncology, confirms that postmenopausal women who have been taking tamoxifen as part of their treatment for early breast cancer for two years can significantly reduce the chance of their breast cancer returning by switching therapy to anastrozole. [i]

The ARNO 95 study, involving 979 patients, was designed to evaluate whether post-menopausal women with hormone-receptor positive early breast cancer who had been receiving endocrine treatment with tamoxifen for two years would benefit from switching to an aromatase inhibitor (AI). The study demonstrated that women switching to anastrozole (n=489) rather than remaining on tamoxifen (n= 490) experienced1:

· 34% reduction in the relative risk of recurrence (HR = 0.66; p=0.049)

· 47% improvement in overall survival (HR = 0.53; p=0.045)

· Fewer serious adverse events (22.7% v 30.8%) (OR = 0.66; p=0.0065)

“This new study is the first individual aromatase inhibitor trial showing a benefit in overall survival in the whole of the study population. The result is particularly striking in that this was a substantial group of patients with a relatively good prognosis (74% node negative). The reason that this result is so important is that improvement in overall survival is the biggest prize of all,” said Professor Jeffrey Tob
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