T. Hassinger1, J. H. Mehaffey1, R. B. Hawkins1, B. D. Schirmer1, P. T. Hallowell1, A. T. Schroen1, S. L. Showalter1 1University Of Virginia,Department Of Surgery,Charlottesville, VA, USA
Introduction: Bariatric surgery is an effective treatment for morbid obesity with long-lasting weight loss. Additionally, elevated body mass index (BMI) is known to be an important risk factor for the development of breast cancer, one of the most common cancer diagnoses among women in the United States. Therefore, we hypothesized that patients undergoing bariatric surgery would have a decreased incidence of estrogen receptor (ER) positive breast cancer when compared to a propensity-matched non-surgical cohort.
Methods: The bariatric population for this study included all female patients that underwent bariatric surgery at a single institution between 1985 and 2015. Patients from all routine outpatient visits were identified from the clinical data repository (CDR) and matched 1:1 with bariatric patients using body mass index (BMI), relevant comorbidities, demographics, and insurance status. The primary outcome of interest was ER positive breast cancer. Chart review was performed on all patients with a breast cancer diagnosis. Univariate analyses were performed to compare the two groups.
Results: A total of 4,860 patients were included in this study, with 2,430 in both the bariatric surgery and non-surgery groups. Median follow-up time from date of surgery or date of initial morbid obesity diagnosis (non-surgery group) was 5.6 years. There was no difference in median age (42.0 [35.0-51.0] vs. 42.0 [31.0-53.0]; p=0.29) or medical comorbidities aside from gastroesophageal reflux disease (713 [29.3%] vs. 149 [6.1%]; p<0.0001). Seventeen (0.7%) patients in the bariatric surgery group were diagnosed with any breast cancer after surgery compared to 32 (1.3%) patients in the non-surgery group (p=0.03). The non-surgery group had more ER positive tumors (4 [36.4%] vs. 22 [71.0%]; p=0.04) as well as larger median tumor size (p=0.02).
Conclusion: Morbidly obese female patients who underwent bariatric surgery were found to have fewer subsequent diagnoses of any breast cancer and ER positive breast cancer when compared to a propensity-matched cohort. These results suggest the possibility of an oncologic benefit to weight-loss surgery.
