Source: DGNews  |  Posted 7 years ago

By Charlene Laino

SAN ANTONIO, TX -- December 9, 2004 -- Switching postmenopausal women to the oral steroidal aromatase inhibitor exemestane after 2 or 3 years of standard tamoxifen therapy improves disease-free survival

According to updated results from the Intergroup Exemestane Study, exemestane achieved a 30% improvement over tamoxifen, a difference that was significant at the P =.00005 level.

Charles Coombes, MD, director, Cancer Research UK Laboratories, Imperial College London, United Kingdom, presented the updated results of the 4,740-patient study here on December 8[^]th[] at the 27[^]th[] Annual San Antonio Breast Cancer Symposium.

At a median follow-up of 37.4 months, the risk of contralateral breast cancer was reduced by 54% in the exemestane arm (P =.04), Dr. Coombes said.

Overall, 193 women in the exemestane arm experienced a local or distant recurrence versus 264 of the women who continued on tamoxifen. There were 12 cases of contralateral breast cancer in the exemestane arm, compared with 26 in the tamoxifen arm.

Death due to any cause occurred in 152 women on exemestane and 187 women on tamoxifen, which translated to a 17% reduction in mortality with exemestane, but the trend did not reach statistical significance (P =.08).

There were 49 deaths due to cancer at sites other than the breast in the exemestane arm compared with 69 in the tamoxifen arm. Cancers of the lung and uterus and melanoma accounted for most of the difference, Dr. Coombes said.

As expected, thromboembolic and gynecologic events were greater in the tamoxifen arm, Dr. Coombes said, while there were more musculoskeletal events in the exemestane group. And while the rates of death due to cardiac disease were similar between the two groups, myocardial infarctions occurred in 20 exemestane patients and eight tamoxifen patients (P =.02).

Pfizer Oncology helped support the research.

[Presentation title: "The Intergroup Exemestane Study: a Randomized Trial in Postmenopausal Patients With Early Breast Cancer Who Remain Disease-Free After Two to Three Years of Tamoxifen-Updated Survival Analysis." Abstract 3]