A New Gold Standard in Early Breast Cancer as Arimidex(TM) (Anastrozole) Overtakes Tamoxifen

2006-12-07 19:31 1112

-- More Patients Set to Benefit as Weight of Evidence for 'Arimidex' Prompts

Wave of Change

MACCLESFIELD, England, Dec. 7 /Xinhua-PRNewswire/ -- Today, for the first

time in over 20 years, a new gold standard treatment has emerged for

postmenopausal women with early breast cancer. In the US, some European

countries and Japan, tamoxifen has been surpassed by 'Arimidex' (anastrozole)

as the most widely prescribed hormonal treatment for post-menopausal women

newly diagnosed with the disease.

The news comes just days prior to the five-year anniversary of the first

presentation of results of the landmark ATAC* trial(1), which many believe

was the catalyst for the wave of treatment change now being seen. Prior to

the ATAC trial, tamoxifen was widely considered the gold standard endocrine

therapy in early breast cancer. However, following the initial results(2) and

further updates from ATAC(3,4), which showed the superiority of 'Arimidex'

over tamoxifen for both efficacy and tolerability, there has been a steady

decrease in the numbers of patients receiving tamoxifen, with doctors

favouring 'Arimidex' instead.

Tamoxifen has been widely credited with driving the dramatic improvements

in survival rates in early breast cancer over the past 10-20 years, reducing

the risk of recurrence by 50% compared with no hormonal treatment(5). Now

experts expect to see even further improvements in the future due to the

additional benefits conferred by 'Arimidex'.

"To my mind, this really does mark a new era in breast cancer treatment,"

said Professor Jeffrey Tobias, Professor of Cancer Medicine at University

College London and one of the ATAC Steering Committee members. "Many cancer

specialists have already recognised the additional benefits of anastrozole

and have been prescribing it for some time, based on solid clinical evidence.

It is now increasingly recognised as the optimal treatment option for many


Following the initial announcement of early results from the ATAC trial

in 2001(1), mounting evidence has demonstrated that 'Arimidex' offers women

an increased chance of remaining cancer free compared with tamoxifen, coupled

with fewer serious side effects. Over the past five years, key findings from

ATAC have demonstrated 'Arimidex' is associated with substantial efficacy and

tolerability benefits over and above those provided with tamoxifen, including


-- 26% reduction in the risk of recurrence (HR = 0.74, p=0.0002)

-- 53% reduction in the risk of contralateral breast cancer

(HR = 0.47, p=0.001)

-- 16% reduction in the risk of distant recurrence (HR = 0.84,


-- 13% reduction in the risk of breast cancer mortality (HR =

0.87, p=0.2)

-- A significantly reduced risk of endometrial cancer, DVT and


Although there is an increased incidence of bone fracture and joint pain

in patients receiving 'Arimidex', these events are considered predictable and

manageable compared with the serious adverse events associated with tamoxifen


The continuing clinical evidence from the ATAC trial, together with major

peer-reviewed publications, recommendations in international and local

guidelines and the assurance generated by what is now over two million years

of patient experience, have all come together to generate this widespread

change in clinical practice. The adoption of 'Arimidex' as a new gold

standard is set to improve outcomes for patients worldwide, and demonstrates

the importance of robust data in providing doctors with the confidence to


"High quality data are essential when evaluating current and new

treatments. Through congresses, publications and guidelines, the

communication routes are there to ensure that physicians are kept up to date

with the latest advancements," added Dr Aman Buzdar of the MD Anderson Cancer

Centre in Texas, and Chair of the ATAC Steering Committee. "The data have

conclusively shown us that more women will stay cancer-free with 'Arimidex'

and fewer will suffer serious side effects. The ultimate rewards are seen in

the day-to-day consultations, with more positive conversations between

physicians and their patients, who have a better chance of remaining

recurrence free."


1. Baum M. The ATAC (Arimidex, Tamoxifen, Alone or in Combination)

adjuvant breast cancer trial in postmenopausal (PM) women.

Breast Cancer Res Treat 2001; 69 (3): 210, Abs 8.

2. ATAC Trialists' Group. Anastrozole alone or in combination with

tamoxifen versus tamoxifen alone for adjuvant treatment of

postmenopausal women with early breast cancer: first results

of the ATAC randomised trial. Lancet 2002; 359 (9324):


3. ATAC Trialists' Group. Anastrozole alone or in combination with

tamoxifen versus tamoxifen alone for adjuvant treatment of

postmenopausal women with early-stage breast cancer - Results

of the ATAC (Arimidex, Tamoxifen Alone or in Combination) trial

efficacy and safety update analyses. Cancer 2003; 98


4. ATAC Trialists' Group. Results of the ATAC (Arimidex,

Tamoxifen, Alone or in Combination) trial after completion of

five years' adjuvant treatment for breast cancer. Lancet 2005;

365 (9453): 60-62.

5. Early Breast Cancer Trialists' Collaborative Group. Effects of

chemotherapy and hormonal therapy for early breast cancer on

recurrence and 15-year survival: an overview of the randomised

trials. Lancet 2005; 365: 1687-1717.

6. ATAC Trialists' Group. Comprehensive side-effect profile of

anastrozole and tamoxifen as adjuvant treatment for early-stage

breast cancer: long-term safety analysis of the ATAC trial.

Lancet Oncology 2006; 7 (8): 633-643.

7. Perez EA. The balance between risks and benefits: Long-term

use of aromatase inhibitors. Eur J Cancer Supplements 2006;

S4: 16-25.

For further information, or to view an educational module on

how 'Arimidex' data have influenced prescribing in early breast cancer to

create a new gold standard, please visit our website .

Notes to Editors

* ATAC - 'Arimidex', Tamoxifen, Alone or in Combination

AstraZeneca is a major international healthcare business engaged in the

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ARIMIDEX is a trademark, the property of the AstraZeneca group of


Source: AstraZeneca