Soy-rich Diet for Preventing Chronic Pain After Breast Cancer Surgery
Preclinical studies indicate that soy consumption suppresses the development of pain
behavior and hyperalgesia following nerve injury. The pain-suppressing properties of soy
protein have been shown to be predominately the result of soy pre-operative consumption.
This is a randomized, double blind, placebo-controlled clinical trial for women diagnosed
with breast cancer and scheduled to undergo breast cancer surgery. The trial will comprise
two phases: 1. A 2-week preoperative dietary manipulation phase, and 2. A one-year
postoperative follow up period. In the first phase eligible candidates will undergo a basic
dietary evaluation followed by stratification into 4 study groups, based on their pre-vs.
postmenopausal status and the planned type of surgery, i.e., formal mastectomy vs.
breast-conserving surgery. Women in each group will be randomized to receive either powdered
soy protein in the experimental group or milk protein in the control group. During the
second, post-surgical phase women will resume their normal diet. If shown to be beneficial,
this simple dietary manipulation may prevent one of the most severe sequelae of breast
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention
Number of women in both arms with any pain of any type in operated breast or its vicinity
12 months post-surgery
Yoram Shir, MD
McGill University Health Center
Canada: Health Canada