In addition to rapid and lasting weight loss and a passel of other health benefits, bariatric surgery has now been linked to a 61 percent reduction in the risk of developing malignant melanoma, a deadly form of skin cancer most closely associated with excessive sun exposure.
The new research, to be presented Thursday at the European Congress on Obesity in Vienna, Austria, also found that people who underwent weight-loss surgery saw their risk of skin cancer in general decline by 42 percent.
That protective effect was seen in a group of 2,007 obese Swedish study participants who chose to undergo bariatric surgery, and were then followed for a median of 18 years.
In the study, the subjects who chose to have the surgery as a treatment for obesity were compared to 2,040 obese Swedes who were similar to the surgical patients in multiple ways—including age, gender, body measurements, cardiovascular risk factors, psychosocial variables and personality traits—but did not go under the knife.
Why a cancer linked to outdoorsmen and sun-worshippers would be stymied after obese patients had their gastrointestinal tracts surgically altered is unclear. But the authors of the study—a group from Sweden's University of Gothenburg led by Magdalena Taube—suggested it was the deep weight loss that altered subjects' risk of melanoma.
The finding "supports the idea that obesity is a melanoma risk factor, and indicates that weight loss in individuals with obesity can reduce the risk of a deadly form of cancer that has increased steadily in many countries over several decades," said Taube and her colleagues.
The American Cancer Society estimates that roughly 91,270 new melanomas will be diagnosed in the United States in 2018—about 55,150 in men and 36,120 in women—and that about 9,320 people will die of the malignancy.
The organization also has reported a recent increase in the incidence of melanoma: Between 2008 and 2018, the number of new melanoma cases diagnosed annually has increased by 53 percent.
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