Lower cancer risk after MBS regardless of age or sex

Metabolic and bariatric surgery (MBS) reduces the risk of obesity-related cancer regardless of sex and age, according to a large Nordic registry study led by researchers at Karolinska Institutet. The results strengthen knowledge about the cancer-preventive effects of MBS for several cancers linked to obesity.

"We found that the reduction in cancer risk after obesity surgery was similar across age groups and between women and men, suggesting that the long-term health benefits of surgery extend to a broad range of patients," said Cecilia Radkiewicz, a researcher at the Department of Molecular Medicine and Surgery, Karolinska Institutet, and first author of the study.

Several cancers linked to obesity, particularly gastrointestinal cancers, are increasing in Western populations. Previous research has suggested that obesity surgery reduces the risk of obesity-related cancers, but the association has appeared stronger among women, and findings for several individual gastrointestinal cancer types have been inconsistent. Whether the cancer-preventive effects of obesity surgery differ according to age at surgery remains largely unexplored.

In the large Nordic registry-based cohort study, researchers at Karolinska Institutet and collaborating institutions investigated how obesity surgery affects the risk of obesity-related cancers and whether the association differs depending on age at surgery or between women and men.

The study included more than 780,000 individuals with obesity in Sweden, Denmark and Finland. Of these, nearly 100,000 had undergone obesity surgery.

Surgery was associated with a lower risk of obesity-related cancer overall and the magnitude of risk reduction did not differ by age group. Associations for non–sex-specific cancers were similar in men and women, however, for individual cancers the strongest inverse associations were observed for liver cancer, endometrial cancer and ovarian cancer. In contrast, pancreatic cancer risk was increased after surgery, particularly among younger adults.

Overall, the researchers found that individuals who underwent surgery had an approximately 20% lower risk of developing obesity-related cancer, compared with individuals with obesity who did not undergo surgery.

The results suggest that the long-term cancer-preventive benefits of obesity surgery extend to a broad range of patients and underscore the value of effective obesity treatment for long-term health.

The findings were reported in the paper, 'Bariatric Surgery and Risk of Obesity-Related Cancer by Age and Sex', published in JAMA Surgery. To access this paper, please click here