Among women with severe obesity, having bariatric surgery linked to lower risk of several obesity-related cancers compared to those who did not undergo the surgery, finds a recent study.
The study included approximately 22,000 people who had bariatric surgery and 66,000 people who did not, matched to the surgery patients by gender, age, BMI and other factors. More than 80 percent of the patients in this study were women. Data was pulled from large integrated health insurance and health care databases.
An average of 3.5 years after the participants underwent surgery, 2,543 people had been diagnosed with some type of cancer.
Those who had undergone bariatric surgery had a 33 percent lower risk of developing any type of cancer compared to their matched counterparts. The link was especially strong for obesity-related cancers, including post-menopausal breast, endometrial and colon.
The study found no association between bariatric surgery and cancer risk among men, possibly because the vast majority of study participants were female, note the authors. At least two of the cancers most impacted by bariatric surgery, postmenopausal breast and endometrial cancers, affect women only.
About 1 in 13 adults are categorized as having extreme obesity, a BMI of 40 or more. In this study, all the patients had a BMI of at least 35. (A BMI of 30 or over is categorized as obese.)
This study has several limitations, such as it was a restrospective study with relatively short follow-up time and there may be unrecognized differences between the surgery and non-surgery matched individuals. And because this is one observational study, it cannot draw a firm causal link to bariatric surgery reducing cancer risk. Yet given that obesity has a clear link to cancer and with more people opting for this surgery, more research is needed in this area.
The study was funded by the National Institutes of Health and National Cancer Institute.
Sources: Daniel P. Schauer, Heather Spencer Feigelson, Corinna Koebnick, Bette Caan, Sheila Weinmann, Anthony C. Leonard, J. David Powers, Panduranga R. Yenumula, David E. Arterburn. Bariatric Surgery and the Risk of Cancer in a Large Multisite Cohort. Annals of Surgery. September 21, 2017.