Management of malabsorptive bariatric surgery after cancer surgery for malignancies of the digestive apparatus

Background: Data regarding management of former bariatric operations after onset of a malignancy are still lacking and there is no consensus whether bariatric surgery negatively influences the oncologic management of patients. Objectives: To investigate the strategy by which patients previously submitted to bariatric surgery were managed after diagnosis of malignancy of the digestive apparatus, whether a revision was performed or not, to assess the incidence of nutritional complications, and the effect of revision versus no revision of bariatric surgery on the outcome of cancer treatment. Setting: University Hospital, Italy. Methods: Occurrence of a malignancy of the digestive apparatus in patients submitted to biliopancreatic diversion was investigated retrospectively. Patients’ data were collected preoperatively, at 2 and 3 years after the operation, at oncologic diagnosis, and at the longest available postoncologic follow-up. Results: From May 1976 to January 2017, 3341 morbidly obese patients were submitted to biliopancreatic diversion. Sixteen patients were diagnosed with a malignancy involving the digestive apparatus 5 to 28 years after bariatric surgery. Of 10 patients diagnosed with colorectal cancer, 6 were revised. At 2 years after biliopancreatic diversion, body mass index, hemoglobin, and iron levels were significantly lower than preoperatively. Serum transferrin and total protein were unchanged. There was no difference between body mass index, hemoglobin, transferrin, and total protein levels at 2 years and at oncologic diagnosis, or between revised and unrevised patients. Conclusion: Revision of a preexisting bariatric operation after digestive cancer surgery is common, although selected, unrevised cases do not seem to be associated with worse outcome.