Aromatase Inhibitors Declared Superior To Tamoxifen In The Adjuvant Treatment Of Early Breast Cancer

Main Category: Breast Cancer
Article Date: 03 Aug 2006 - 0:00 PDT

email to a friend   printer friendly   view / write opinions   rate article

An international panel of leading breast cancer specialists, in an opinion paper published today, agreed that aromatase inhibitors (AIs) surpass tamoxifen as the most effective treatment option for postmenopausal women with early, hormone-sensitive breast cancer.

This global opinion, published in Current Medical Research and Opinion, declares the consensus findings of The International Aromatase Inhibitor Expert Panel, composed of 24 breast cancer clinicians from Europe, the USA, Australia, China and Brazil, who agreed that AIs should be prescribed as the preferred therapy in this patient setting. The panel's findings reaffirm current guidelines regarding the use of aromatase inhibitors, such as ARIMIDEX®. ARIMIDEX is approved for adjuvant treatment (treatment following surgery with or without radiation) of postmenopausal women with hormone receptor-positive early breast cancer.

"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. This guidance helps to clarify considerations for use of AIs in everyday practice. These data provide the evidence that support using an aromatase inhibitor at the earliest opportunity," commented panel member Dr. Aman Buzdar, professor of medicine for the department of breast medical oncology at The University of Texas M. D. Anderson Cancer Center in Houston.

The Panel reviewed data from major early breast cancer aromatase treatment trials with the aim of providing a "rational interpretation of the impact of these data on current practice and to highlight areas where further investigation is needed." The conclusions of the paper include several evidence based-recommendations. A summary of a few of the Panel's top-line findings include:

-- AIs are superior to tamoxifen and should be considered the treatment of choice in postmenopausal women with newly diagnosed hormone-sensitive, early breast cancer.

-- Although five years of tamoxifen treatment has been the standard of care for 20 years and remains an effective treatment for certain patients, there is no subgroup of patients who do not appear to benefit from initial AI adjuvant therapy.

-- Reported gynecological adverse events are substantially reduced with AIs compared with tamoxifen. The majority of these adverse events with tamoxifen occur during the first 2.5 years of treatment, and may cause a burden to compliance

-- An increased risk of fractures are seen with AIs compared with tamoxifen, but they appear to be predictable and manageable. AI therapy is also associated with an increase in joint symptoms. The mechanisms explaining these conditions are unknown. The relationship of coronary heart disease (CHD) to AI use requires further evaluation.

-- Current evidence suggests that AIs have either no or little effect on CHD and the presence of CHD should not impact on the prescribing of AIs for adjuvant use. Further follow-up is required to determine whether differences between the AIs exist.

"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 panel member Professor Rowan Chlebowski, of the Harbor-UCLA Medical Center, California. "The data in support of AIs are very strong."

The consensus paper coincides with the publication of mature data from the landmark ATAC (ARIMIDEX, Tamoxifen, Alone or in Combination) trial in the Lancet Oncology. 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.

About ARIMIDEX® (anastrozole)

ARIMIDEX is indicated for adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer.

Important Safety Information About ARIMIDEX

ARIMIDEX should only be used in postmenopausal women. ARIMIDEX can cause fetal harm when administered to a pregnant woman. Before starting treatment, pregnancy must be excluded (see WARNINGS in full Prescribing Information). Common side effects seen with ARIMIDEX in the early breast cancer clinical trial include hot flashes, joint symptoms, weakness, mood changes, pain, sore throat, nausea and vomiting, depression, high blood pressure, osteoporosis, swelling of arms-legs, and headaches. Fractures, including spine, hip, and wrist fractures, occurred more often with ARIMIDEX than tamoxifen.

ARIMIDEX should not be taken with tamoxifen or estrogen-containing therapies.

About Tamoxifen

NOLVADEX® (tamoxifen citrate) is approved for the adjuvant treatment of node-positive and node-negative early breast cancer in postmenopausal women following breast surgery and radiation. In some NOLVADEX adjuvant studies, most of the benefit to date has been in the subgroup with four or more positive axillary nodes.

Important Safety Information About Tamoxifen

WARNING: Serious and life-threatening events associated with NOLVADEX include cancer of the uterus, stroke, and blood clots, some of which have been fatal. In clinical trials, uterine cancers, including endometrial cancer and uterine sarcomas, and blood clots, including clots in the lungs, occurred 2 to 4 times more often with NOLVADEX than placebo, but each occurred in less than 1% of women. For most women with breast cancer, the benefits of NOLVADEX outweigh its risks. If you are taking NOLVADEX to reduce your risk of developing breast cancer because you are at high risk or have DCIS, you should discuss these warnings with your health care provider.

Women who are pregnant or who plan to become pregnant should not take NOLVADEX. Women who have a history of blood clots or who currently use anticoagulants (blood thinners) should not take NOLVADEX for DCIS or to reduce their risk of breast cancer. Cataracts and cataract surgery occurred more frequently with NOLVADEX. The most frequently reported adverse reactions were hot flashes and vaginal discharge.

Please see full Prescribing Information including boxed WARNING regarding NOLVADEX Tablets.

About AstraZeneca

AstraZeneca (NYSE:AZN) 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. In the United States, AstraZeneca is a $10.77 billion healthcare business with more than 12,000 employees. AstraZeneca is listed in the Dow Jones Sustainability Index (Global) as well as the FTSE4Good Index.

For more information about AstraZeneca, please visit: http://www.astrazeneca-us.com

ARIMIDEX and NOLVADEX are registered trademarks of the AstraZeneca group of companies.