IRB Number:

1908-03

Trial Status:

Open for Enrollment

Phase: III

Why is this study being done?

This research study is being done to:

• see if the combination of ovarian function suppression using a GnRH analogue plus tamoxifen is better at stopping the return of breast cancer than the combination of ovarian function suppression using a GnRH analogue plus exemestane;
• compare the effects (good and bad) of exemestane to the effects of tamoxifen.
• see how the treatment affects how well the patient feels.
• see if there are any effects (good and bad) that happen after treatment has stopped.

Who is Eligible to Participate in the Study?

Premenopausal women diagnosed with breast cancer may be eligible to participate in this research study.

What is Involved With this Study?

Ovarian function suppression (OFS) shuts down the ovaries and stops them from making hormones such as estrogen. In this study we will use triptorelin or goserelin for the GnRH analog, and patients will take both the GnRH analogue and either tamoxifen or exemestane for 5 years.

All women in this study will get a monthly injection of a GnRH analogue (triptorelin or, if intolerant to, triptorelingoserelin) that shuts down the ovaries. When the ovaries shut down, estrogen levels in the blood drop. In addition, patients will get tamoxifen or another hormonal agent called exemestane. In pre-menopausal women, the ovaries make most of the estrogen in the body. Estrogen can cause breast cancer cells to grow and divide. Tamoxifen acts by blocking the interaction of estrogen with the cancer cells. In post-menopausal women or women who are getting injections to shut down their ovaries, most estrogen is made by an enzyme in the body called aromatase. Exemestane makes the aromatase enzyme stop working, which lessens the amount of estrogen in the blood.

Patients will be randomized into one of the study groups described below.

Group A	Group B
Surgery + GnRH analogue for 5 years + Tamoxifen for 5 years	Surgery + GnRH analogue for 5 years + Exemestane for 5 years

How long will the Study run?

Patients will get the hormone treatment for 5 years unless the disease comes back. However, patients will continue to be followed on this study for the rest of their life to see if the cancer ever comes back.

Who can I Contact for Additional Information on this Trial?

Complete Request Form for Cancer Clinical Trial Information at Mayo Clinic or
For more information about this study or other clinical trial options, please contact our Mayo Clinic Cancer Center Clinical Trials Referral Office.

• Patients living within the United States, call 507-538-7623, or e-mail cancerclinicaltrials@mayo.edu


• Patients living outside the United States may call our International Office at 507-284-8884, or e-mail intl.mcr@mayo.edu.

What is/are the Locations of this Clinical Trial?

• Rochester, MN
• Jacksonville, FL

Last updated: 05/07/2008