"This provides further evidence for a connection between obesity and malignant skin cancer, and for the view that we should regard obesity as a risk factor for these forms of cancer," said study first author Magdalena Taube from University of Gothenburg in Sweden.
That obesity is a risk factor for several types of cancer is well known. The same applies to the fact that people's risk level can be lowered by means of an intentional weight reduction.
However, the evidence for a connection between obesity and weight loss on the one hand and, in particular, malignant skin cancer on the other has been limited to date.
The findings, published in the journal JAMA Dermatology, used data from the SOS (Swedish Obese Subjects) study.
Other data sources included the Swedish Cancer Register kept by the Swedish National Board of Health and Welfare.
The researchers studied a group of 2,007 people who underwent bariatric surgery, and compared them with a control group of 2,040 individuals.
The surgery group included 23 individuals who developed malignant skin cancer, i.e. squamous cell carcinoma or malignant melanoma, in parallel with marked weight loss.
The median follow-up period was just over 18 years.
The largest difference related to malignant melanoma: 12 people in the surgery group were affected, against 29 in the control group.
The researchers found that bariatric surgery was associated with significantly reduced risks for melanoma and skin cancer in general.
The skin cancer risk reduction was not associated with baseline body mass index or weight; insulin, glucose, lipid, and creatinine levels; diabetes; blood pressure; alcohol intake or smoking.
The results of this study suggest that bariatric surgery in individuals with obesity is associated with a reduced risk of skin cancer, including melanoma.
( With inputs from IANS )