The Bariatric Surgery Is Associated with a Lower Incidence of Malignancy: Real World Data from Taiwan

Purpose: This study assessed the benefits and efficacy of bariatric surgery (BS) in reducing the risk of cancer in Asians with morbid obesity.

Methods: Records for patients aged between 18 and 55 years whose diagnoses corresponded with the ICD-9 codes for obesity and BS were extracted from the National Health Insurance Research Database (NHIRD) in Taiwan between 2000 and 2015. The patients who underwent BS (BS group), those who did not undergo BS (NS group), and the general population (GP group) were propensity score matched. The outcome was newly diagnosed malignancy. Data were extracted from the Registry for Catastrophic Illness Patient Database (RCIPD) of the NHIRD.

Results: The BS group developed significantly less malignancy (1.18%) than the GP group (1.46%, p = 0.0364). There was no statistically significant difference in malignancy risk between the BS and GP groups (aHR =1.00, p = 0.9997). The NS group developed significantly higher malignancy (2.48%) than the GP group (1.97%, p < 0.0001). There was a significantly higher malignancy risk in the NS group (aHR =1.22, p < 0.0001) than in the GP group. In the subgroup analysis, the malignancy risks of the NS group were significantly higher in the subgroup of men aged between 18 and 35 years (aHR =1.37, p = 0.003) and women aged between 18 and 35 years (aHR = 1.62, p < 0.0001), and 35-55 years (aHR = 1.27, p < 0.0001). All the subgroup analyses between the BS and GP groups demonstrated no significant differences.

Conclusions: Our study demonstrated that BS reduced the risk of malignancy in patients with morbid obesity, particularly in women and young men.