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Intestine Bacteria and Breast Cancer Risk

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01461070
Recruitment Status : Completed
First Posted : October 27, 2011
Last Update Posted : May 27, 2020
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Cancer Institute (NCI) )

Brief Summary:


- Some bacteria found in the large and small intestines help keep people healthy and aid digestion. They may also affect a person s risk of developing cancer. Researchers want to study the relationship between intestinal bacteria and breast cancer risk factors. They can do this by looking at stool and urine samples from postmenopausal women.


- To study intestinal bacteria and its relationship to urine-based markers of breast cancer risk in women.


- Women between 55 and 69 years of age with a recent mammogram that showed no signs of cancer.


  • Participants will be screened with a medical history and basic health questionnaire.
  • At home, participants will complete questionnaires about cancer risk factors and food consumption.
  • Participants will also collect urine and stool samples. They will send the samples to the designated labs for study.
  • No treatment will be provided as part of this protocol.

Condition or disease
Breast Neoplasms

Detailed Description:

Background/Significance: Commensal microbes (the microbiota), particularly in the gut, are required for human health and are postulated to affect cancer risk through several mechanisms. This proposed study builds upon a pilot within the NCI Division of Cancer Epidemiology and Genetics (DCEG) that identified highly acceptable methods for collecting fecal specimens and significant correlation between fecal microbial beta-glucuronidase activity and a marker of breast cancer risk, urine levels of estrogens. The proposed study will determine the correlation between levels of fecal enzyme activities and systemic estrogens in a random sample of postmenopausal women at Kaiser Permanente Colorado (KPCO). Demonstration of an association between the fecal microbiota and systemic estrogens would help to motivate future studies of how microbes affect cancer risk.

Objectives: The main objective is to characterize the fecal microbiota and its association with levels of systemic estrogens among randomly sampled postmenopausal female members of a health maintenance organization (HMO). A secondary objective will determine the proportions of women who consent and then provide questionnaire data, a fecal specimen to characterize the microbiota, and a urine specimen to quantify systemic estrogens; and differences between participants (N=60) and non-participants. A third objective will determine whether consecutive, newly diagnosed postmenopausal breast cancer cases have similar participation rates, fecal microbiota characteristics and urine estrogen levels compared to the randomly sampled women.

Methods: We will randomly sample from the KPCO population of approximately 50,000 women ages 55-69 who have recently had a negative screening mammogram. An invitation packet (letter, information pamphlet, consent form, eligibility questionnaire, and opt-out postcard) will be sent in batches of 100, up to a maximum of 500 women. The consenting women will receive a second packet with a cancer risk-factor questionnaire, a link to the on-line Block brief food frequency questionnaire, and a specimen collection kit (with illustrated instructions) for collecting a fecal and urine specimen. Participants (minimum 60, maximum 80) will ship the specimens to the DCEG repository. As amended, consecutive newly diagnosed breast cancer cases (target N=60) will be enrolled in the oncology clinic prior to definitive surgery, with the same eligibility criteria as for the random sample. For contemporaneous controls, participants in the randomly sampled, mammogram-negative population will be recruited back (target N=60). Urine estrogens will be quantified by DCEG at NCI Frederick. Fecal microbial classification and enzymatic expression and activity will be performed at the University of Maryland Medical School (UMMS).

Analyses: Data will be analyzed and summarized for publication with representatives from KPCO, DCEG and UMMS. Simple proportions will be used to estimate participation rates. Extant electronic records at KPCO will be used to compare participants to non-participants, overall and by pre-specified subgroups (5-year age groups, race/ethnicity, length of KPCO enrollment), with descriptive statistics and logistic regression. For the primary objective, fecal microbial 16S rRNA pyrosequences will be classified by phylogenetic and principal components analyses, while estrogen levels and Beta-glucuronidase RNA expression and enzymatic activity levels will be categorized using log standard deviations. The study will have 80% power to detect a 17% increase in estrogen level per 2.4-fold increase in glucuronidase activity and 80% power to detect a 3-fold case-control difference in above-median microbiome alpha diversity.

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Study Type : Observational
Actual Enrollment : 175 participants
Observational Model: Case-Control
Time Perspective: Cross-Sectional
Official Title: BRANCH:Fecal Microbiota Among Participants in a Pre-paid Health Plan
Actual Study Start Date : August 10, 2011
Actual Primary Completion Date : June 30, 2014
Actual Study Completion Date : May 22, 2020

Resource links provided by the National Library of Medicine

Breast Cancer Cases
Breast Cancer Cases

Primary Outcome Measures :
  1. Breast cancer association [ Time Frame: cross-sectional ]
    breast cancer association

Secondary Outcome Measures :
  1. Fecal microbiome-systemic estrogen association [ Time Frame: cross-sectional ]

Biospecimen Retention:   Samples With DNA
Feces and urine.

Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years to 69 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Examining fecal microbiota in women with breast cancer

Female members of Kaiser Permanente Colorado (KPCO) with a recent normal mammogram who gets into a random sample of the very large population.


History of cancer, except non-melanoma skin cancer

History of inflammatory bowel disease or diverticulitis

History of gastric banding or by-pass surgery

History of other gastric or intestinal surgery within the previous 6 months

Hormone prescription within the previous 12 months

Antibiotic prescription within the previous 6 months.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01461070

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United States, Colorado
Kaiser Permanente Colorado
Denver, Colorado, United States
Sponsors and Collaborators
National Cancer Institute (NCI)
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Principal Investigator: Rashmi Sinha, Ph.D. National Cancer Institute (NCI)
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Responsible Party: National Cancer Institute (NCI) Identifier: NCT01461070    
Other Study ID Numbers: 999911235
First Posted: October 27, 2011    Key Record Dates
Last Update Posted: May 27, 2020
Last Verified: May 2020
Keywords provided by National Institutes of Health Clinical Center (CC) ( National Cancer Institute (NCI) ):
Breast Cancer
Post Menopausal Estrogens
Fecal Microbes
Additional relevant MeSH terms:
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Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases