Evaluating the Correlation of Bariatric Surgery and the Prevalence of Cancers in Obese Patients: A Study of the National Inpatient Sample (NIS) Database

Purpose Obesity is a global pandemic that exerts a significant burden on healthcare worldwide. Multiple cancers, as well as deaths from the same, are more prevalent in obese patients. Bariatric surgery has been shown to be the most effective way of treating obesity once other measures have been exhausted. There is no concordant data available to support that bariatric surgery can reduce the prevalence of cancer. Using one of the largest data samples, we evaluate the correlation of bariatric surgery in morbidly obese patients with the prevalence of obesity-related cancers (breast, endometrial, esophageal, colorectal, prostate, and renal) in morbidly obese patients. Patients and methods A sample of 7,672,508 morbidly obese patients was identified from the 1994 to 2004 records of the National Inpatient Sample (NIS) database, divided into those who did and did not undergo bariatric surgery, and studied for the prevalence of obesity-associated cancers. Results Obesity was predominantly seen in the Caucasian population (68.22%). The mean age of cases who underwent bariatric surgery was younger when compared to those who did not undergo the procedure (43.89±25.16 vs. 54.90±36.40, p-value <0.0001). The highest bariatric surgery rate was seen in the Northeast (5.57%), followed by the West (4.15%), South (3.02%), and Midwest (2.96%) (p-value <0.0001). Overall, the odds of morbidly obese patients who underwent bariatric surgery and developed cancer are: esophageal cancer 0.19 (0.1218-0.3078, p <0.0001), colorectal cancer 0.0368 (0.0275- 0.0493, p <0.0001), endometrial cancer 0.0155 (0.0099-0.0244, p <0.0001), breast cancer 0.0712 (0.0582-0.0871, p <0.0001), prostate cancer 0.0285 (0.0199-0.0408, p <0.0001) and renal cancer 0.0182 (0.0106-0.0314, p <0.0001). The odds of cancer post-bariatric surgery remained significantly lower even after matching certain confounding factors. Conclusions The odds of developing breast, esophageal, prostate, renal, and colorectal cancers are significantly lower in morbidly obese patients who undergo bariatric surgery.