Pancreatic Cancer Risk Affected by Exposure to Sunlight
When it comes to pancreatic cancer, here is an example of when having a history of skin cancer could actually be a good thing. Results of a new study indicate that several factors associated to exposure to sunlight may affect pancreatic cancer risk.
What is the role of sunlight in pancreatic cancer?
Pancreatic cancer is a challenging disease for several reasons, not least of which is the fact that research concerning risk factors has uncovered conflicting results. This is especially true when discussing vitamin D, which was pointed out in a recent study from the National Cancer Institute.
In that review, entitled "Is dietary fat, vitamin D, or folate associated with pancreatic cancer?" the authors noted that "Studies that measured vitamin D exposure differently have shown inconsistent results," and that "Dietary studies suggest protective associations, whereas studies of circulating 25-hydroxyvitamin D status show null or positive associations with low or very high concentrations, respectively."
Now in a new study, presented at the American Association for Cancer Research's Pancreatic Cancer: Progress and Challenges conference, Australian investigators reported that their findings support previous studies showing exposure to sunlight helps protect against pancreatic cancer.
To arrive at this conclusion, principal investigator Rachel Neale, PhD, at Queensland Institute of Medical Research, and her colleagues enrolled 714 individuals with pancreatic cancer and matched them with 709 cancer-free controls. Information regarding sunlight exposure, birth location, skin type, and skin cancer history was gathered.
After evaluating the data, the investigators deducted the following results:
- People born in areas that had the highest levels of ultraviolet radiation had a 24% lower risk of developing pancreatic cancer when compared with people who were born in areas with low radiation
- Individuals whose skin was the most sensitive to the sun had a 49% reduced risk for pancreatic cancer compared with people who had the least sun-sensitive skin
- Participants who had a history of skin cancer or skin lesions related to sun exposure had a 40% lower risk for pancreatic cancer compared with people without such a history
Other possible risk factors for pancreatic cancer
A 2009 study published in the Journal of the National Cancer Institute showed that people who ate high amounts of saturated fat had 36% higher rates of pancreatic cancer compared with individuals who ate low amounts.
Consumption of high fructose corn syrup also has been named as a possible risk factor for pancreatic cancer. In a University of California, Los Angeles study, investigators revealed that fructose triggers a key pathway in the body that stimulates pancreatic cancer cell division, which promotes rapid growth of the disease.
On a positive note, a study published in early 2012 reported that higher intakes of fiber could reduce pancreatic cancer risk. Specifically, the greatest intake of soluble fiber was associated with a 60% reduced risk while insoluble fiber was linked to a 50% lower risk.
When it comes to sunlight exposure as a risk factor for pancreatic cancer, Neale explained that more research is needed. "There are several trials of vitamin D that are either under way or planned, and pooling data from these might give some clue about vitamin D and pancreatic cancer," she noted.
Neale RE et al. Association between ambient ultraviolet radiation at birth, skin type, skin cancer history, and pancreatic cancer. AACR PCC 2012
Sanchez GV et al. Is dietary fat, vitamin D, or folate associated with pancreatic cancer? Molecular Carcinogenesis 2012 Jan; 51(1): 119-27