The risk of developing hematologic malignancies may decrease following bariatric surgery in patients with overweight or obesity, according to a recent study published by Sjöholm et al in The Lancet Healthy Longevity.
Background
Previous studies have shown that overweight and obesity may be risk factors for several types of cancers. Although female patients with obesity may be more susceptible to cancer than male patients with obesity, the risk may decrease with intentional weight loss. However, evidence of any links among obesity, weight loss, and hematologic malignancies has been limited.
Study Methods and Results
In the new study, investigators used the Swedish Obese Subjects study and the Cancer Registry at the National Board of Health and Welfare to compare the outcomes of 2,007 patients with obesity who underwent bariatric surgery with 2,040 patients with obesity who did not undergo the procedure. The investigators noted that aside from the procedure, the patients were otherwise comparable in terms of gender, age, body composition, cardiovascular risk factors, and psychosocial variables.
After the follow-up period, the investigators found that 1.7% (n = 34) of the patients in the bariatric surgery group developed hematologic malignancies compared with 2.5% (n = 51) of those in the control group.
Most of the hematologic malignancies were lymphomas. When they were studied separately, the risk of lymphoma and all hematologic malignancies reduced by a respective 55% and 40% among patients who underwent bariatric surgery.
In particular, female patients with high blood sugar at baseline appeared to benefit from bariatric surgery.
“The benefit of the surgery is linked to baseline blood glucose levels. The reduced risk of [hematologic malignancies] was much more pronounced if the [female patient’s] blood sugar levels were high at the beginning, which clearly shows that blood sugar is an important factor in cancer development,” emphasized senior study author Magdalena Taube, PhD, Associate Professor of Molecular and Clinical Medicine at the Sahlgrenska Academy at the University of Gothenburg.
Conclusions
The investigators indicated that the factors contributing to the link between obesity and hematologic malignancies may be complex and involve multiple factors—such as chronic inflammation and clonal hematopoiesis. They suggested that the metabolic improvements that take place following bariatric surgery, including reduced inflammation, may reduce the risk of cancer.
“The results provide further support of considering obesity a risk factor for [hematologic malignancies], and that bariatric surgery can reduce the risk of … cancer in [female patients with obesity],” concluded Dr. Taube.
Disclosure: For full disclosures of the study authors, visit thelancet.com.
