New results from one of the world’s largest breast cancer trails herald hope for thousands of women
Benefits of Arimidex (anastrozole) over tamoxifen at preventing all forms of breast cancer recurrence increase over time
- even four years after treatment ends
San Antonio, USA, Friday 14 December 2007: New data from ATAC*, one of the world’s largest and longest-running studies in postmenopausal women with early breast
cancer, reinforce that anastrozole can help many more women live cancer-free, for longer. For the first time, follow-up
research shows anastrozole to be better than tamoxifen in preventing tumours from returning long term.1,2 If cancer
returns, women are much more likely to die – therefore, preventing breast cancer from returning (“recurrence”) at any
stage of treatment is key to saving lives.
The landmark results – presented today at the prestigious annual San Antonio Breast Cancer Symposium (SABCS), USA and
also published online in The Lancet Oncology –show that even four years after a woman’s treatment ends, the protective
effect of anastrozole in reducing the risk of hormone-sensitive early breast cancer from returning continues to
increase. Overall, women in the ATAC trial taking anastrozole were 24% less likely to have their cancer come back,
compared with those taking tamoxifen.1,2 This demonstrates the long-term impact of treatment decisions made at diagnosis
and confirms the importance of starting treatment with anastrozole to help more women beat this devastating disease.
Breast cancer currently affects 1.1 million women worldwide per year 3 and hormone-sensitive early disease accounts for
around 75% of all cases of breast cancer in postmenopausal women. 4
Presenting the data at SABCS, Professor John Forbes, Newcastle Mater Misericordiae Hospital, Australia commented: “Preventing recurrence is the primary goal in breast cancer management. If we can stop the cancer from returning, we can
save more lives, more often. These exciting long-term follow-up data show that anastrozole is a more effective treatment
option than tamoxifen for postmenopausal women with hormone-sensitive early stage disease – thus it is imperative these
women get the most effective treatment at the earliest opportunity after diagnosis.”
Professor Forbes continued: “Prior to the ATAC trial, tamoxifen was the standard of care for women with hormone-sensitive disease, with substantial
evidence to support its crucial place in practice. However, these new 100-month data from ATAC show us that compared
with tamoxifen, anastrozole can significantly reduce the risk of recurrence and minimise life-threatening side effects.
Most encouragingly, the data also show us that the protective effect of anastrozole lasts well beyond the standard
treatment period of five years and in my opinion confirms there is no longer any rationale for prescribing tamoxifen.”
A recent global survey showed that over 70% of physicians believe that telling a patient her breast cancer has come back
is worse than giving a diagnosis of early breast cancer.6 Recurrence, in the same breast, in the opposite breast or at a
distant tumour site means that the cancer is more likely to be incurable and the patient is at risk of a bad outcome. It
is therefore essential for both patients and their doctors to know they are on a better therapy than tamoxifen to
prevent the disease returning.
The impact of treatment on quality of life is also an important consideration in early breast cancer, and data have
shown that the clinical benefits of anastrozole are achieved without adversely affecting the quality of patients’
“The ATAC 100-month data confirm that anastrozole is now the gold standard treatment for post-menopausal women with
hormone-sensitive early breast cancer, irrespective of their recurrence risk, and is set to improve the outcomes of
patients worldwide,” commented Professor Anthony Howell, Christie Hospital, UK.
Arimidex (anastrozole) is a trademark, the property of the AstraZeneca group of companies.
* ATAC: Arimidex, Tamoxifen, Alone or in Combination Trial studied postmenopausal women diagnosed with early breast
cancer in the poast five years and who had undergone breast cancer surgery.
ATAC 100-month results summary:
After a median follow-up of over 8 years (100 months), compared with tamoxifen, anastrozole significantly:1,2
reduces the risk of all recurrences by 24% (HR 0.76 [0.67-0.87]; p=0.0001)
improves disease free survival by 15% (HR 0.85 [0.76-0.94]; p=0.003)
reduces the risk of distant metastases (recurrence elsewhere in the body) by 16% (HR 0.84 [0.72-0.97]; p=0.022)
reduces the incidence of contralateral breast cancer (cancer in the opposite breast) by 40% (OR 0.60 [0.42-0.85];
Prescribing anastrozole from the start means fewer patients have to be told the devastating news that their breast
cancer has recurred.1,2
The study will be published early online (00.01GMT Saturday 15 December) and in the January edition of The Lancet
‘More Positive Conversations’ global survey
The ‘More Positive Conversations’ survey was conducted online and via telephone interviews by Harris Interactive on
behalf of AstraZeneca. The survey involved 1,062 physicians and patients from France, Germany, Italy, the United Kingdom
and the US.
AstraZeneca is a major international healthcare business engaged in the research, development, manufacture and marketing
of prescription pharmaceuticals and the supply of healthcare services. It is one of the world's leading pharmaceutical
companies with healthcare sales of $26.47 billion and leading positions in sales of gastrointestinal, cardiovascular,
neuroscience, respiratory, oncology and infection products. AstraZeneca is listed in the Dow Jones Sustainability Index
(Global) as well as the FTSE4 Good Index.
The ATAC Trialist Group –Effect of anastrozole and tamoxifen as adjuvant treatment for early-stage breast cancer; 100
month analysis of the ATAC trial -published online, Lancet Oncology Saturday 15 December
Forbes J, on behalf on the ATAC Trialist’s Group. ATAC: 100 month median follow-up shows continued superior efficacy
and no excess fracture risk for anastrozole compared with tamoxifen after treatment completion. Abstract no 41. San
Antonio Breast Cancer Symposium 2007.
Parkin, D.M., E. Laara, and C.S. Muir, Estimates of the worldwide frequency of sixteen major cancers in 1980. Int J
Cancer, 1988. 41(2): p. 184-97.
Breastcancer.org. What role to hormones play in breast cancer treatment. Available from http://www.breastcancer.org/treatment/hormonal/what_is_it/hormone_role.jsp
. (Last accessed October 2007)
Cella et al, Quality of life of postmenopausal women in the ATAC (‘Arimidex’, Tamoxifen, Alone or in Combination) trial
after completion of 5 years’ Adjuvant Treatment for early breast cancer. Breast Cancer Research and Treatment, 2006.
100(3): p. 273-284.
Data on file, ‘More Positive Conversations’ global survey, conducted by Harris Interactive (US) March-May 2007.