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The Effect of Soy Protein on Post- Breast Cancer Surgery Pain

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ClinicalTrials.gov Identifier: NCT01047774
Recruitment Status : Terminated (Difficulty with recruitment - few eligible for enrolment.)
First Posted : January 13, 2010
Last Update Posted : October 7, 2015
Information provided by (Responsible Party):

January 12, 2010
January 13, 2010
October 7, 2015
March 2010
May 2013   (Final data collection date for primary outcome measure)
Number of women in both arms with any pain of any type in operated breast or its vicinity [ Time Frame: 12 months post-surgery ]
Same as current
Complete list of historical versions of study NCT01047774 on ClinicalTrials.gov Archive Site
  • Pain intensity (acute) [ Time Frame: Up to 7 days post-surgery ]
  • Pain intensity (chronic) [ Time Frame: Up to 12 months post-surgery ]
  • Analgesic medication use [ Time Frame: Up to 12 months post-surgery ]
  • Pain quality [ Time Frame: Up to 12 months post-surgery ]
  • Anxiety and Depression [ Time Frame: Up to 12 months post-surgery ]
  • Disability [ Time Frame: Up to 12 months post-surgery ]
  • Adverse events [ Time Frame: 2 weeks during dietary supplementation ]
  • Childhood and adolescence consumption of soy [ Time Frame: Baseline ]
  • Adverse events [ Time Frame: Up to 12 months post-surgery ]
  • Pain intensity (acute) [ Time Frame: Baseline and post-surgery days 1, 2, 4 and 7 ]
  • Pain intensity (chronic) [ Time Frame: Baseline and post-surgery months 3, 6 and 12 ]
  • Analgesic medication use [ Time Frame: Throughout the study ]
  • Pain quality [ Time Frame: Baseline, Post-surgery months 3, 6 and 12 ]
  • Anxiety and Depression [ Time Frame: Baseline, post-surgery months 3, 6 and 12 ]
  • Disability [ Time Frame: Baseline, post-surgery months 3, 6 and 12 ]
  • Adverse events [ Time Frame: Thoughout the study once dietary supplementation begins ]
  • Childhood and adolescence consumption of soy [ Time Frame: Baseline ]
Not Provided
Not Provided
The Effect of Soy Protein on Post- Breast Cancer Surgery Pain
Soy-rich Diet for Preventing Chronic Pain After Breast Cancer Surgery
The incidence of chronic pain after breast cancer surgery (CPBCS) is high in women diagnosed with breast cancer. Similar to other chronic postoperative pain conditions, existing treatments for CPBCS do not always work. Adopting the concept of using pain relieving measures prior to surgery rather than after it, may lead to decreased postoperative pain levels. Soy has been shown to have pain-relieving properties and may reduce the risk for developing chronic post-surgical pain. The purpose of this study is to determine the effects of adding soy protein to the diet before surgery on the development of chronic pain.

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 cancer.

Phase 2
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
  • Pain
  • Chronic Disease
  • Breast Cancer
  • Dietary Supplement: Isolated soy protein
    30-50g of protein powder daily for 2 weeks.
    Other Names:
    • PRO-FAM 873
    • Code #066873
  • Dietary Supplement: Isolated milk protein
    30-50g of protein powder daily for 2 weeks.
    Other Name: PRODIET 85
  • Experimental: Soy protein
    Intervention: Dietary Supplement: Isolated soy protein
  • Placebo Comparator: Milk protein
    Intervention: Dietary Supplement: Isolated milk protein
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
May 2013
May 2013   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Women diagnosed with breast cancer and scheduled for elective breast cancer surgery (excluding breast biopsy) with axillary lymph node dissection (total and/or sentinel node excision).
  • Women who are 21 years or older.

Exclusion Criteria:

  • History of significant heart, gastro-intestinal, liver or kidney disease.
  • Use of the anticoagulant, warfarin or Coumadin.
  • Malabsorption of any kind.
  • Diagnosed lactase deficiency.
  • Known allergy to any of the tested dietary products.
  • Basic daily consumption of soy protein in quantities exceeding 10 g/day.
  • Women who are strict vegetarians (i.e. no animal derived dietary sources).
  • The use of the following narcotics or adjuvant pharmacotherapy: opioids, anticonvulsants, antidepressants and steroids (except antidepressant use specifically for depression).
  • Tumour size (if known) > 3cm(i.e. size before pre-operative chemotherapy, if administered).
  • Locally advanced breast cancer.
  • Inflammatory breast cancer.
  • Paget's disease of the breast with palpable mass.
  • Suspected metastasis.
  • Suspected micrometastasis.
  • Previous breast surgery of any kind (except needle biopsy).
  • The need for bilateral breast surgery.
  • The existence of other known cancer, including metastasis, either in the other breast or elsewhere.
  • Previous or current endocrine cancer therapy (e.g. selective estrogen receptor modulators, aromatase inhibitor).
  • Body mass index (BMI) > 35.
Sexes Eligible for Study: Female
21 Years to 99 Years   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
5R21CA125873-02 ( U.S. NIH Grant/Contract )
Not Provided
Not Provided
Dr. Yoram Shir, McGill University Health Center
Dr. Yoram Shir
  • National Cancer Institute (NCI)
  • Louise & Alan Edwards Foundation
  • McGill University
Principal Investigator: Yoram Shir, MD McGill University Health Center
McGill University Health Center
October 2015

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP