June 20, 2012

Sun Exposure & Pancreatic Cancer

(Ivanhoe Newswire) — Sun exposure is usually associated with being the cause of cancer, but a new study shows its protective function: it can actually decrease your risk of pancreatic cancer.

"Several ecological studies, including one conducted in Australia, have suggested that people living in areas with high sun exposure have lower risk for pancreatic cancer," Rachel Neale, Ph.D., principal investigator at Queensland Institute of Medical Research in Queensland, Australia, was quoted as saying. "However, some studies of circulating vitamin D indicate that people with high vitamin D are at increased risk, and one study of vitamin D intake supports this increased risk."

The results of this study back up existing ecological data indicating that sun exposure has a protective effect against pancreatic cancer.

Between 2007 and 2011, 714 people in Queensland, Australia were recruited for the study and matched by age and sex to 709 control participants. All of them were interviewed about sociodemographic information and medical history; they were also asked about their birth location, skin cancer history, and skin type defined by color, tanning ability and propensity to sunburn.

They used NASA's Total Ozone Mapping Spectrometer to assign a level of ultraviolet (UV) radiation to each birth location and split them into thirds based on how much radiation was present. They found that participants born in areas with the highest levels of UV radiation had a 24 percent lower risk for developing pancreatic cancer compared with those born in low UV radiation areas.

Additionally, although all skin types had some association with pancreatic cancer risk, those who were classified as having the most sun-sensitive skin had a 49 percent decreased risk for pancreatic cancer compared to those who were classified as having the least sun-sensitive skin. Finally, participants who had a history of skin cancer or other sun-related skin lesions had a 40 percent lower risk for pancreatic cancer than those without skin lesions.

"There is increasing interest in the role of sun exposure, which has been largely attributed to the effect of vitamin D, on cancer incidence and mortality," Dr. Neale was quoted as saying. "It is important that we understand the risks and benefits of sun exposure because it has implications for public health messages about sun exposure, and possibly about policy related to vitamin D supplementation or food fortification."

Dr. Neale suggested that researchers conduct large cohort studies that evaluate sun exposure comprehensively, and serum vitamin D.

"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," Dr. Neale was quoted as saying.

Source: American Association for Cancer Research's Pancreatic Cancer: Progress and Challenges conference, June 2012