Time for Change - Aromatase Inhibitors Such as ARIMIDEX(TM) Confirmed Superior to tamoxifen
Macclesfield, England (ots/PRNewswire)
- International Panel of Breast Cancer Specialists Agree: 'With Successful Adjuvant Therapy, Early Breast Cancer is Potentially a Curable Condition.'
- ATTN: Health Professional Press
- For International Journalists - Not for US Media
Today, leading breast cancer experts advised unequivocally that 5 years' tamoxifen, for so long regarded as the 'gold standard' hormonal breast cancer therapy, is no longer the most effective treatment option for postmenopausal women with early, hormone-sensitive breast cancer. This global consensus was published today in Current Medical Research and Opinion and advises doctors that they should be prescribing aromatase inhibitors (AIs), such as ARIMIDEX(TM) (anastrozole), to prevent recurrence and ultimately reduce mortality. The International Aromatase Inhibitor Expert Panel, which included 24 leading breast cancer clinicians from Europe, the USA, Australia, China and Brazil, agreed that with successful post-surgery treatment, patients with early breast cancer can potentially be cured of their condition and that AIs, such as anastrozole, should be prescribed as the preferred therapy(1).
"Over the last three years, there has been an influx of new information about the use of aromatase inhibitors in early breast cancer, and while this is great news, it has created a great deal of confusion. Physicians have been looking for clear guidance on whether it is better for our patients to move on from tamoxifen in favour of an AI. The guidance from an elite group of breast cancer experts published today, helps to clarify how best to use AIs in everyday practice. We can now be confident that to provide the best care for our patients, we should be using an aromatase inhibitor at the earliest opportunity," commented Dr. Aman Buzdar of the MD Anderson Cancer Centre, Texas, and a member of the Panel.
The global consensus document provides vital guidance for clinicians who are faced with making crucial treatment decisions on behalf of their patients on a daily basis. The Panel reviewed data from all the major early breast cancer AI treatment trials with the aim of providing a 'rational interpretation of the impact of these data on current practice'. The overarching conclusion of the paper is not only that patients newly diagnosed with hormone-sensitive early breast cancer should receive an AI following initial surgery but that women who are already taking tamoxifen, should consider changing their treatment to an AI(1).
Evidence-based recommendations
In the consensus statement published today, the Panel made several evidence based-recommendations. A summary of the Panel's topline findings are below:(1)
- AIs are superior to tamoxifen and are, therefore, the treatment of choice in postmenopausal women with hormone-sensitive, early breast cancer. In newly diagnosed patients, AIs are considered the preferred therapy, and patients already receiving tamoxifen should consider switching to an AI.
- Although 5 years' tamoxifen has been the standard of care for 20 years, and remains an effective treatment for certain patients, there is no subgroup of patients who would not benefit from initial AI adjuvant therapy.
- Reported gynaecological adverse events are substantially reduced with AIs compared with tamoxifen. The majority of gynaecological adverse events with tamoxifen occur during the first 2.5 years of treatment, and cause a burden to the patient that may affect compliance with therapy.
- Risks associated with tamoxifen treatment, namely deep vein thrombosis, stroke and endometrial cancer, cannot be monitored for nor predicted in individual patients. This is a crucial difference between the management of patients receiving adjuvant therapy with tamoxifen or AIs. By prescribing an AI, physicians can be confident that they are giving their patients the best opportunity to stay cancer free for longer, without the risk of potentially life-threatening side effects.
- Als are associated with increased risk of osteoporotic fracture compared with tamoxifen, however current data confirms bone problems with AIs are predictable and appear to be manageable.
The consensus paper coincides with the publication of mature data from the landmark ATAC* trial in the Lancet Oncology(2). Anastrozole is the only AI with mature safety and tolerability data, as well as a favourable risk:benefit profile compared to tamoxifen, for the full 5-year treatment period. The results further support the Panel's findings and add to the evidence base for AIs, specifically anastrozole, as the preferred treatment for postmenopausal women with hormone-sensitive early breast cancer.
"Although tamoxifen has served us well for over 20 years, if we want to give our patients the most effective and well tolerated treatment for their breast cancer, it's time to consider an AI," explained Professor Rowan Chlebowski, of the Harbor-UCLA Medical Centre, California, and a member of the Panel. "The data in support of AIs, and for anastrozole in particular, is overwhelming and there's no doubt that tamoxifen is no longer the gold standard treatment for these women."
The full consensus paper can be accessed via the Current Medical Research and Opinion website: http://www.cmrojournal.com. In addition, the publication of the mature data from the ATAC trial is available on the Lancet Oncology website: http://oncology.thelancet.com.
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 $23.95 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 FTSE4Good Index.
'Arimidex' is a trademark, the properties of the AstraZeneca group of companies.
For further information, please visit our website www.astrazenecapressoffice.com
Notes to Editors:
* ATAC - 'Arimidex', Tamoxifen, Alone or in Combination
Over the past few years, many studies have been published concerning the relative efficacy and safety profiles of tamoxifen and the aromatase inhibitors as adjuvant therapy for postmenopausal women with early hormone receptor-positive breast cancer. Recently, debate has centred around trials which have studied tamoxifen versus AIs as initial adjuvant therapy, switching and sequencing strategies, and extended adjuvant therapy.
In December 2005, a group of 24 breast cancer experts from the USA, UK, France, Germany, Spain, Italy, Australia, Belgium, Sweden, China and Brazil, met to review efficacy and safety data from the recent major trials investigating tamoxifen and the third-generation AIs in postmenopausal women which have challenged the perception of tamoxifen as optimum adjuvant endocrine therapy. Data from the ATAC(3), BIG 1-98(4), MA.17(5), IES(6), ITA(7), ABCSG Trial 8(8) and ARNO 95(8) trials were considered to provide a rational interpretation of the impact of these data on current practice and to highlight areas where further investigation is needed.
References:
1. Buzdar A, Chlebowski R, Cuzick J et al. Defining the role of aromatase inhibitors in the adjuvant endocrine treatment of early breast cancer. Curr Med Res Opin 2006;22(8):1575-85
2. The 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. http://oncology.thelancet.com. Published online 19 July, 2006
3. ATAC Trialists' Group. Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial after completion of 5 years' adjuvant treatment for breast cancer. Lancet 2005;365:60-2
4. Thurlimann B, Keshaviah A, Coates A, et al. A comparison of letrozole and tamoxifen in postmenopausal women with early breast cancer. N Engl J Med 2005;353:2747-57
5. Goss PE, Ingle JN, Martino S, et al. A randomized trial of letrozole in postmenopausal women after five years of tamoxifen therapy for early-stage breast cancer. N Engl J Med 2003;349:1793-802
6. Coombes RC, Hall E, Gibson LJ, et al. A randomized trial of exemestane after two to three years of tamoxifen therapy in postmenopausal women with primary breast cancer. N Engl J Med 2004;350:1081-92
7. Boccardo F, Rubagotti A, Puntoni M, et al. Switching to anastrozole versus continued tamoxifen treatment of early breast cancer: preliminary results of the Italian Tamoxifen Anastrozole trial. J Clin Oncol 2005;23:5138-47Jakesz R, Samonigg H, Greil R et al. Extended adjuvant treatment with anastrozole: results from the Austrian Breast and Colorectal Cancer Study Group Trial 6a (ABCSG-6a). J Clin Oncol (Meeting Abstracts) 2005;23:10s, abs 527
8. Jakesz R, Jonat W, Gnant M, et al. Switching of postmenopausal women with endocrine-responsive early breast cancer to anastrozole after 2 years' adjuvant tamoxifen: combined results of ABCSG trial 8 and ARNO 95 trial. Lancet 2005;366:455-62
Contact:
Contact: Lynn Grant, Global PR Director, Oncology, Direct Line:
+44-(0)1625-517-406, Mob: +44-(0)7715-484-917, Email:
Lynn.Grant@Astrazeneca.com. Sara Singer, Shire Health International,
Direct Line: +44-(0)20-7108-6521, Mob: +44-(0)7881-810-328, Email:
sara.singer@shirehealthinternational.com