You might not think that obesity has anything at all to do with skin cancer. Yes, obesity has been linked as a clear risk factor to other cancers, but…skin cancer? Doesn’t that have more to do with fair skin, family history, and sun exposure?
While scientists still don’t entirely understand the relationship between obesity and skin cancer, there are some theories going around. One points towards the chronic inflammation that is associated with obesity, which can, in turn, create the right conditions for tumor growth. Another has to do with the sedentary lifestyle that often accompanies obesity. However, these theories still lack much structure – which is why new research recently published in the journal JAMA Dermatology is so interesting.
The recent study suggests that individuals with obesity who undergo weight loss surgery have a reduced risk of developing skin cancer, including melanoma. Based on a Swedish study from 2009 that found a reduced risk of cancer for women with obesity who had undergone bariatric surgery, this new analysis focuses especially on skin cancer in order to "investigate the association between bariatric surgery and skin cancer, including melanoma."
In conducting the study, the research team followed up with the participants in the original study for an average of 18.1 years. The participants were classified into two groups: 2,007 individuals with obesity who underwent bariatric surgery and 2,040 matched control participants who had obesity but did not undergo bariatric surgery.
The team’s findings showed a significant difference in skin cancer risk between the two groups. In the surgery group, 23 individuals had developed malignant skin cancer — squamous cell carcinoma or malignant melanoma – within the follow-up period, compared to 45 individuals in the non-surgery group.
First author Magdalena Taube, Ph.D., commented: "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."
While melanoma makes up only 1% of skin cancer cases in the US, it is the number one killer for all skin cancers, which is the most common form of cancer in the country. Every year, approximately 96,480 people receive new melanoma diagnoses in the United States.
"These findings suggest that melanoma incidence is significantly reduced in patients with obesity after bariatric surgery and may lead to a better understanding of melanoma and preventable risk factors,” conclude the authors.