BAriaTric Surgery After Breast Cancer Treatment (BATS)

This is a feasibility study to gain an understanding of the willingness of women with a history of early stage breast cancer and current obesity to enroll in a weight-loss study, accept an assigned intervention (bariatric surgery with lifestyle intervention or lifestyle intervention alone), and comply with the study plan for 1 year. If there is successful enrollment in this study, the plan is to use what is learned in this study to design a larger, longer-term clinical trial to look at the effect of weight loss and incidence of cancer recurrence.

Inclusion Criteria: * Diagnosis of breast cancer in the previous 10 years and currently disease free. * Completion of breast cancer treatment (radiation, chemotherapy) at least \> 6 months prior to enrollment * Body mass index (BMI) of ≥ 35 kg/m2, but \< 50 kg/m2. * 18 through 67 years of age at enrollment * Deemed healthy enough to undergo bariatric surgery, if assigned intervention, as determined by a surgeon and documented in the medical record. * Must have insurance coverage with no exclusion for obesity related treatment or management of obesity related surgical complications - in general insurance coverage is available for persons with a BMI ≥ 35 kg/m2. * Anticipated ability to abide by study requirements demonstrated in part by, but not limited to, successful completion of run-in assessments. * Willingness to accept randomization into either interventional group. * Provides voluntary written consent prior to performance of any research related activities. Exclusion Criteria: * Cardiovascular event (myocardial infarction, acute coronary syndrome, coronary artery angioplasty or bypass, stroke) in the past six months. * Current evidence of congestive heart failure, angina pectoris, or symptomatic peripheral vascular disease. * Cardiac stress test indicating that surgery or lifestyle would not be safe. * 12-lead EKG indicating that surgery would not be safe. * Significant anemia (hemoglobin 1.0 g/dL or more below normal range) or history of coagulopathy. * History of stomach surgery, bile duct surgery, pancreatic surgery, splenectomy, or colon resection. * Gastric or duodenal ulcer in the past six months. * History of intra-abdominal sepsis except for uncomplicated appendicitis or diverticulitis more than six months prior to enrollment. * Self-reported HIV-positive status, active tuberculosis, active malaria, chronic hepatitis B or C, cirrhosis, or inflammatory bowel disease. * Currently pregnant or nursing, or planning to become pregnant in the next 15 months. * History of alcohol, drug, or opioid dependency (excluding nicotine) in the past five years. * Active psychosocial or psychiatric problem that is likely to interfere with adherence to the protocol. * Deemed not an acceptable candidate by a trained psychologist. * Current participation in a conflicting research protocol. * Presence of any chronic or debilitating disease that would make adherence to the protocol difficult. * Gastroesophageal reflux disease requiring medications. History of endoscopy demonstrating esophagitis or Barrett's changes in the esophagus. * Any history of dysphagia.