It is proven that obese people who have had bariatric or metabolic surgery see their risk of cancer decrease, especially those linked to obesity, compared to those not operated. But is risk reduction as significant when compared to the general population? This is what a Swedish team wanted to know, in a study published in the journal Obesity.
Obesity increases the risk of cancer of postmenopause, endometrium, ovarian, hepatocellular, colorectal, pancreatic, gallbladder, esophagus, gastric cardia, renal, thyroid and several multiple and meningiomas. More recently, a correlation has been highlighted with non -Hodgkin’s lymphoma.
The analysis of Swedish researchers relates to a cohort of 68,424 patients who received a Roux-en-Y primary bypass (RYGB) (55,358) or a Sleeve Gastrectomy (13,066) between 2007 and 2020, compared to nearly 641,000 controls adjusted according to age, gender and place of residence.
Only the risk of breast and skin cancer is lower than that of the general population
All cancers combined, the study has shown a risk of a similar new cancer between obese people who have had bariatric surgery and the general population (noticed obese people included) with an incidence ratio (IRR) of 1.03.
Differences are however present according to the type of tumor. Thus, compared to controls, the patients operated had a reduced risk of cancers of the female breast (irr = 0.78) and skin cancer, melanoma (irr = 0.77) and non-melanoma (irr = 0.71) in men and women. On the other hand, on the other hand remains present for colon cancers (irr = 1.42), liver (irr = 1.29), pancreatic (irr = 1.81), endometrium (irr = 1.69), renal (irr = 2.96), malignant meningiomas (irr = 1.45) and non -hodgkin 1.30).
Some disparities are also observed according to surgery. The increase in the risk of colon, liver and pancreas cancer and the reduction in the prevalence of women’s breast cancer are only associated with the bypass.
In view of their results, the study authors recommend maintaining cancer screening for patients operated identical to those used in the general population.
