Malignancy in bariatric surgery patients: a French multisite cohort

Background Bariatric surgery is associated with decreased cancer-related mortality. An indefinite proportion of patients that undergo bariatric surgery have a history of malignancy or will develop cancer. In these patients, weight loss and oncologic evolution needed to be assessed. The aim of this study was to report the results of patients diagnosed with malignancy before and after bariatric surgery in a French multisite cohort. Methods We conducted a retrospective cohort study of all patients who underwent bariatric surgery in six university centers. Patients were divided in two groups: patients with a preoperative history of malignancy and patients diagnosed with malignancy during the follow-up. Both groups were compared with control groups of patients that underwent surgery during the same period. Results From 2008 to 2018, 8927 patients underwent bariatric surgery. In patients with a history of malignancy (n = 90), breast and gynecologic cancers were predominant (37.8%). Median interval between malignancy and surgery was 60 (38-118) months. After a follow-up of 24 (4-52) months, 4 patients presented with cancer recurrence. Comparative analysis demonstrated equivalent weight loss one year after surgery. In patients with postoperative malignancy (n = 32), breast and gynecologic cancers were also predominant (40.6%). Median interval between surgery and malignancy was 22 (6-109) months. In the comparative analysis, weight loss was similar at 2 years. Conclusions History of malignancy should not be considered as an absolute contraindication for bariatric surgery. Gynecological cancer screening should be reinforced before and after surgery. The development of malignancy postoperatively does not seem to affect mid-term bariatric outcomes.