Effects of Chemotherapy on Intestinal Bacteria in Patients With Newly Diagnosed Breast Cancer

Changes in Intestinal Microbiota in Association With Chemotherapy Treatment

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.

PRIMARY OBJECTIVES:

I. To examine the transitory and longer lasting effects of chemotherapy on the gut microbiota.

SECONDARY OBJECTIVES:

I. To examine the relationship between body composition and gut microbiota before and after chemotherapy.

II. To examine the relationship between blood estrogen levels and gut microbiota before and after chemotherapy.

TERTIARY OBJECTIVES:

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 adjuvant chemotherapy.

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.

Inclusion Criteria:

• 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 pregnant
• Provide informed consent

Exclusion Criteria:

• 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