Long-term cancer outcomes after bariatric surgery

Area of Science:

• Oncology
• Bariatric Surgery
• Epidemiology

Background:

• Obesity is a significant risk factor for developing various cancers.
• Bariatric surgery leads to substantial and sustained weight loss, making post-surgical patients valuable for studying cancer associations.
• Understanding the impact of weight loss on cancer risk is crucial for public health.

Purpose of the Study:

• To investigate the association between bariatric surgery and subsequent cancer incidence and mortality.
• To stratify cancer outcomes by obesity-related and non-obesity-related cancers, sex, and cancer stage.
• To compare cancer risk in bariatric surgery patients versus a matched nonsurgical control group.

Main Methods:

• A retrospective cohort study involving 21,837 bariatric surgery patients and an equal number of matched nonsurgical controls.
• Data collected retrospectively from 1982 to 2019, with surgeries performed between 1982 and 2018.
• Surgical procedures included gastric bypass, gastric banding, sleeve gastrectomy, and duodenal switch. Outcomes analyzed included cancer incidence and mortality.

Main Results:

• Bariatric surgery patients exhibited a 25% lower risk of developing any cancer compared to the nonsurgical group (HR 0.75).
• Cancer incidence was significantly lower in female surgery patients (HR 0.67) but not in male patients.
• Female surgery patients showed a 41% lower risk for obesity-related cancers and significantly lower cancer mortality (HR 0.53).

Conclusions:

• Bariatric surgery is associated with reduced overall cancer incidence and lower obesity-related cancer incidence in female patients.
• Significant reductions in cancer mortality were observed among females who underwent bariatric surgery compared to their nonsurgical counterparts.
• Weight loss achieved through bariatric surgery appears to have a protective effect against cancer, particularly in women.