Bariatric surgery, a weight loss operation, is associated with a 61 per cent decrease in the risk of developing malignant skin cancer, according to a study. Melanoma is a deadly form of skin cancer, most closely associated with excessive sun exposure. Obesity is an established risk factor for cancer and some studies indicate that intentional weight loss sometimes reduces the risk.
However, evidence for a link between obesity, weight loss and malignant melanoma is limited.
The new findings showed that bariatric surgery led to a 42 per cent reduced risk of skin cancer in general compared to controls given usual obesity care.
The study "supports the idea that obesity is a melanoma risk factor and indicates that weight loss in individuals with obesity can reduce the risk of bariatric surgery that has increased steadily in many countries over several decades", said lead author Magdalena Taube from the University of Gothenburg in Sweden.
The results were presented at the 2018 European Congress on Obesity in Vienna, Austria.
The protective effect of bariatric surgery on skin cancer was observed in a group of 2,007 obese participants who were then followed for a median of 18 years.
These were compared with a control group consisting of 2,040 individuals who matched with the participants who underwent surgery on sex, age, anthropometric measurements, cardiovascular risk factors, psychosocial variables and personality traits.
To analyse malignant melanoma incidence, statistical tests were used to compare time to first melanoma cancer diagnosis between the surgery and control groups.
In additional analyses, risk ratios between the surgery and control groups were compared.