Soy Protein Supplement In Treating Hot Flashes in Postmenopausal Women Receiving Tamoxifen for Breast Disease

OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients
are stratified according to duration of hot flashes (less than 9 months vs 9 months or more)
and frequency of hot flashes (7 to 9 per day vs more than 9 per day). For more information
regarding the treatment regimens, please see the treatment arms section.

Primary objectives:

1. To compare the effect of daily soy supplementation versus placebo on the daily number
of hot flushes experienced by postmenopausal women taking tamoxifen measured at three
months from baseline

2. To compare the effect of daily soy supplementation versus placebo on hot flush severity
as measured by the average daily hot flash score in this population of women measured
at three months from baseline

Secondary objectives:

1. To evaluate the effect of soy supplementation as compared to women randomized to
placebo on quality of life as measured by the Medical Outcomes Study (MOS) sleep
subscale, the Mental Health Inventory (MHI), the CES-D Short Form, the Menopause and
Reproductive Health Questionnaire, and the General Quality of Life Form

2. To measure the effect of soy supplementation as compared to women randomized to placebo
on serum isoflavones, estradiol, SHBG, IGF1 and IGFBP3 levels as measures of hormonal
change

3. To estimate the effect of daily soy supplementation versus placebo on the time to first
relief of hot flushes

A total of 112 patients accrued on this study. Patients were followed 6 months
post-randomization.

Eligibility Criteria:

1. Histologic documentation of atypical ductal hyperplasia, ductal carcinoma in situ
(DCIS), lobular carcinoma in situ (LCIS), or invasive adenocarcinoma of the breast
stages I-III A.

2. Current daily tamoxifen use. Any planned surgery, adjuvant chemotherapy or radiation
must have been completed.

3. History of bothersome hot flushes: ≥ 7 hot flushes/day, sufficiently severe that
intervention is desired. Participants must have had bothersome hot flushes for at
least one month prior to enrollment.

4. Postmenopausal status: surgical menopause, no menses for ≥ 1 year or postmenopausal
FSH levels.

5. No concurrent use of vitamin E, progestins (Megace® or others), clonidine, belladonna
derivative or commercially available soy supplement preparations for treatment of hot
flushes. Participants must have at least a 4-week washout period prior to day 1 of
run-in if any of these have been used.

Participants may be taking low doses of vitamin E that are part of a multivitamin.

6. Concurrent use of anti-depressant, such as Paxil® , Prozac®, or Effexor® is allowed
if the participant has been on a stable dose for more than a month and the purpose of
the medication is for other than control of hot flushes. If SSRI's are used for hot
flashes, they must be discontinued for 4 weeks prior to day 1 of run-in.

7. No concurrent systemic hormone replacement therapy or use of vaginal estrogen creams.
Use of the estradiol releasing vaginal ring (Estring®) is allowed.

8. No history of soy or milk intolerance

9. CALGB performance status 0-2