IES

Disease site: Breast Cancer

Treatment Modality: Hormone Therapy

Status: In active follow-up

The trial recruited 4,740 post-menopausal women from 37 countries between 1998 and 2003, who had undergone surgery for breast cancer and taken tamoxifen for two to three years. Half of the group continued taking tamoxifen while the other half switched to exemestane to complete a total of five years of hormone treatment. The trial has 3 associated sub-studies looking at bone metabolism, endometrial changes and quality of life.

The trial is run by the ICCG in collaboration with the ICR-CTSU and is run under the auspices of the Breast International Group. The ICCG overseas the activities of 20 cooperative trials groups located in 37 countries worldwide which have local responsibility for the trial.

In 2004 the trial released results early due to a significant reduction in the risk of recurrence or death in patients who switched to exemestane. In 2007 an updated analysis with over 2.5 years post treatment follow-up showed that the early disease related benefits appeared to be maintained and that exemestane reduces the risk of dying by approximately 17%. Exemestane also appeared to be safe and well tolerated with no significant differences seen in relation to cardiovascular events, small increases in musculoskeletal side effects, in particular fractures and fewer gynaecological symptoms.

Chief Investigator: Professor R. C. Coombes, Imperial College, London.

Sponsor: Pfizer

Source of funding: Pfizer

ISRCTN: 11883920.

This is an International Collaborative Cancer Group (ICCG) trial.

Recent publications:

Coleman RE, Banks LM, Girgis SI, Vrdoljak E, Fox J, Cawthorn S, Patel A, Coombes RC, Bliss JM, Kilburn LS on behalf of the Intergroup Exemestane Study. Reversal of skeletal effects of endocrine treatments in the Intergroup Exemestane Study (IES). San Antonio Breast Cancer Conference 2008; Abstract 1128.

Coombes, Paridaens, Jassem et al, 2006. American Society of Clinical Oncology Conference. First mature analysis of the Intergroup Exemestane Study (IES).

Fallowfield, Bliss, Porter et al, 2005. J Clin Oncol. Quality of life in the Intergroup Exemestane Study. A randomized trial of exemestane versus continued tamoxifen after 2 to 3 years of tamoxifen in postmenopausal women with primary breast cancer.

Banks, Girgis, Coleman, et al, 2005. J of Bone Min Res (20) suppl 1 S327.Skeletal effect of exemestane in patients with breast cancer.

Coleman, Banks, Girgis et al, 2005. Br Canc Res & Treat 94 (Suppl 1) S233. #5076. Skeletal effects of exemestane in the Intergroup Exemestane Study (IES) – 2 year bone mineral density (BMD) and bone biomarker data.

Coombes, Hall, Gibson et al, 2004. N Engl J Med 350: 1081-1092. A Randomized Trial of Exemestane after Two to Three Years of Tamoxifen Therapy in Postmenopausal Women with Primary Breast Cancer.

Coombes, Bliss and Hall, 2004 N Engl J Med. Adjuvant treatment of breast cancer with exemestane – Reply.

Jassem, Hall, Coombes et al, 2004. 4th European Breast Cancer Conference. Surgical approaches to early breast cancer in the Intergroup Exemestane Study: large differences by country and geographical region.

Fallowfield, Coster, Murray et al, 2002. San Antonio Breast Cancer Conference. Patient reported side effects after 2 to 3 years adjuvant tamoxifen.