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.
