"These women are taking a double hit on their bones -- they are postmenopausal and they are taking aromatase inhibitors -- so they are at extra risk of suffering osteoporosis, and need a preventive agent such as Zometa," said Mei Dong, MD, a clinical research scientist, Novartis Oncology, East Hanover, New Jersey.

In her presentation in a poster session on December 14^th, Dr. Dong detailed how her research team enrolled, 1667 women involved in 2 studies, 1 in North America and the other in Europe, Latin America, Australia, and Asia.

The women were divided into 2 groups; 833 women were administered the intravenous bisphosphonate zoledronic acid (Zometa) 4 mg every 6 months concurrently with oral letrozole (Femara) 25 mg daily; 834 women taking Femara did not receive zoledronic acid until after imaging scan indicating bone loss or if they suffered symptomatic or asymptomatic nontraumatic fractures.

After 6 months, women taking the bisphosphonate therapy upfront had increased bone density by 1.5% at the lumbar spine compared with a 1.8% loss in bone density among patients not receiving the additional treatment.

After 12 months, patients receiving bisphosphonate therapy had increased bone density by 2% compared with a 3% loss in bone density among women in the delayed bisphosphonate group. The difference at 12 months reached statistical significance at the P < .001 level, Dr. Dong reported.

After 6 months, women taking the bisphosphonate therapy upfront had increased bone density by 0.8% at the hip compared with a 1.3% loss in bone density among patients not receiving the additional treatment.

Bone density after 12 months had increased by 2.2% in patients receiving bisphosphonate therapy compared with a 2.1% loss among women in the delayed bisphosphonate group. The difference at 12 months reached statistical significance at the P < .001level, Dr. Dong said.

One patient in the concurrent treatment group suffered grade 2 renal impairment believed to be the result of the treatment; 2 women in the delayed group had grade 3/4 renal impairment, but in neither case was kidney impairment assigned to zoledronic acid treatment.

About 1.5% of patients in the concurrent treatment group discontinued due to serious adverse events compared with 1.0% of patients on the delayed treatment schedule.

In the 12-month period, 10.7% of the delayed treatment patients began zoledronic acid treatment, Dr. Dong said.


[Presentation title: An Integrated Analysis of Zoledronic Acid (ZA) for Prevention of Aromatase Inhibitor Associated Bone Loss (AIBL) in Postmenopausal Women (PMW) With Early Breast Cancer (BCa) Receiving Adjuvant Letrozole (LET).]

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