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

University of Southern California36 enrolled

Overview

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.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Ductal Breast Carcinoma In Situ

Eligibility

Sex: FEMALEMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Change in intestinal microbiota (composition, abundance, and diversity)

Paired sample t-test will be used to determine whether there are significant changes in microbiota diversity (as measured by the number of taxonomic groups) between pre-treatment levels and 1 and 4 months after the final chemotherapy treatment. Mixed-model linear regression on repeated measures will be used to concurrently adjust for physical activity, dietary intakes, and other factors.

Time frame: Baseline to 4 months after final adjuvant (or neoadjuvant) chemotherapy course

Secondary Outcomes

Change in body composition based on dual-energy x-ray absorptiometry (DEXA)

Analyses of body composition measures will be based on fat mass, lean mass, and bone mineral content (BMC); each will be expressed in kilograms, on arms, legs, and trunk. Mixed effects regression models will be used to compare changes per week between pre-treatment assessment and 1 and 4 months after last chemotherapy. Additional analyses will use BMI group (normal, overweight, obese) for stratification and as a covariate in regression models. The relationship between body composition and gut microbiota before and after chemotherapy will be examined.

Time frame: Baseline to 4 months after last chemotherapy

Baseline estradiol and estrone levels

Changes in the microbiota composition, abundance and diversity will be correlated with baseline estradiol and estrone levels.

Time frame: Baseline

Change in estrogen levels

Correlation analyses of changes in the microbiota with changes in estrogen levels will be performed. Mixed effects regression analysis will be used to model systemic estrogen levels as a function of microbiota abundance and diversity, adjusting for cancer treatment, and baseline tumor and other individual characteristics.

Time frame: Baseline to up to 4 months after last chemotherapy