- Patients with obesity who have bariatric surgery have a reduced risk for skin cancer, including melanoma.
- The findings of this trial suggest some association of obesity with skin cancer.
Why this matters
- Obesity is a known general risk factor for some cancers, but its associations with skin cancer, especially melanoma, are not established.
- Median follow-up was 18.1 years.
- Melanoma risk was reduced after bariatric surgery: adjusted subhazard ratio, 0.43 (95% CI, 0.21-0.87; P=.02).
- Incidence rates were 0.8 (95% CI, 0.6-1.2) per 1000 person-years without surgery vs 0.3 (95% CI, 0.2-0.6) per 1000 person-years with surgery.
- General skin cancer risk also decreased after the surgery: adjusted subhazard ratio, 0.59 (95% CI, 0.35-0.99; P=.047).
- Incidence rates for general skin cancer were 1.2 (95% CI, 0.9-1.6) per 1000 person-years without surgery vs 0.7 (95% CI, 0.4-1.0) per 1000 person-years with surgery.
- No association was found with baseline BMI, body weight, metabolic measures, BP, alcohol intake, or smoking.
- Nonrandomized controlled trial, Sweden, 25 surgery departments, 480 primary health care centers.
- Cancer event data for 4042 patients were analyzed.
- Funding: National Institute of Diabetes and Digestive and Kidney Diseases; Swedish government and foundations.
- Skin cancer incidence was not a predefined endpoint.