This pilot research trial studies the effects of chemotherapy on intestinal
bacteria/organisms (microbiota) in patients newly diagnosed with breast cancer. Change in
intestinal microbiota may be associated with weight gain in patients treated with
chemotherapy. Weight gain has been also associated with cancer recurrence. Examining the
types and quantity of bacterial composition in the stool of breast cancer patients treated
with chemotherapy may help determine whether body weight and composition are associated with
changes in the intestinal microbiota and allow doctors to plan better treatment to prevent
weight gain and possibly disease recurrence.
I. To examine the transitory and longer lasting effects of chemotherapy on the gut
I. To examine the relationship between body composition and gut microbiota before and after
II. To examine the relationship between blood estrogen levels and gut microbiota before and
I. To examine the relationship between changes in the gut microbiota by pre-treatment body
mass index (BMI) (normal - BMI < 25 kg/m^2, overweight - BMI >= 25-< 30 kg/m^2, and obese-
BMI >= 30 kg/m^2) and by changes in body composition in relation to chemotherapy.
OUTLINE: Patients are assigned to 1 of 3 groups.
GROUP A: Patients undergo collection of stool samples at baseline (before surgery), at 1
week before initiation of adjuvant chemotherapy (after surgery), and at 1 and 4 months after
completion of adjuvant chemotherapy.
GROUP B: Patients undergo collection of stool samples at baseline (after surgery), at 1 week
before initiation of adjuvant chemotherapy, and at 1 and 4 months after completion of
GROUP C: Patients undergo collection of stool samples at baseline, 1 month after completion
of neoadjuvant chemotherapy (before surgery), and at 1 and 4 months after surgery.
- Newly diagnosed ductal carcinoma in situ or invasive breast cancer (stage I, stage
IIA, stage IIB, and stage IIIA breast cancer)
- A treatment group including surgery followed by standard treatment of adjuvant
chemotherapy such as doxorubicin and cyclophosphamide followed by paclitaxel,
docetaxel and cyclophosphamide, or a treatment group including neoadjuvant
chemotherapy followed by surgery at the Norris or LAC+USC Medical Center
- Women of child-bearing potential agree to pregnancy test to confirm she is not
- Provide informed consent
- Metastatic, recurrent, synchronous or metachronous breast cancer
- History of other cancers (other than non-melanoma skin cancer)
- History of autoimmune celiac or inflammatory bowel disease
- Past bariatric surgery
- Current or recent pregnancy or nursing (within past 12 months)
- Past treatment with chemotherapy
- Recent use (within past month) of more than 3 days of antibiotics use
- Current use of probiotic supplements