Featured Research

from universities, journals, and other organizations

Two Studies Find Evidence That Sunlight May Have Beneficial Influence On Cancer

Date:
February 8, 2005
Source:
Journal Of The National Cancer Institute
Summary:
Two new studies in the February 2 issue of the Journal of the National Cancer Institute have found that sun exposure may have a beneficial influence on some types of cancer. One study found an association between sun exposure and increased survival from melanoma, a potentially deadly form of skin cancer for which sun exposure is a risk factor, while the other found an association between sun exposure and a reduced risk of non-Hodgkin lymphoma.

Two new studies in the February 2 issue of the Journal of the National Cancer Institute have found that sun exposure may have a beneficial influence on some types of cancer. One study found an association between sun exposure and increased survival from melanoma, a potentially deadly form of skin cancer for which sun exposure is a risk factor, while the other found an association between sun exposure and a reduced risk of non-Hodgkin lymphoma.

Solar radiation is a major risk factor for melanoma. The incidence of and mortality from melanoma have been increasing over the last 50 years in all developed countries with large Caucasian populations. But as the incidence of melanoma increases, so does survival, suggesting the possibility that increasing sun exposure increases melanoma survival in addition to melanoma incidence. However, increased early detection of melanoma might also explain the increased survival.

To examine the relationship between sun exposure, early detection, and melanoma survival, Marianne Berwick, Ph.D., M.P.H., of the University of New Mexico in Albuquerque, and colleagues conducted a population-based, case–control study of more than 500 patients from the Connecticut Tumor Registry who had been diagnosed with melanoma in the late 1980s.

Three measures of sun exposure--sunburn, high intermittent sun exposure, and solar elastosis (an indicator of the skin's sun damage)--and a personal history of skin awareness (a measure of early detection) were all inversely associated with death from melanoma. Melanoma patients with higher levels of sun exposure or skin awareness were less likely to die. In addition, both solar elastosis and skin awareness were independently associated with increased survival from melanoma, even after adjusting for certain melanoma characteristics, such as lesion thickness and location. The authors conclude that sun exposure is associated with increased survival from melanoma.

"It would be reasonable to speculate … that the apparently beneficial relationship between sun exposure and survival from melanoma could be mediated by vitamin D," Berwick and colleagues write. "However, an alternative hypothesis is that sun exposure induces less aggressive melanomas by inducing melanization and increasing DNA repair capacity, both of which might reduce further mutational changes in a melanoma. Which, if either, hypothesis is more plausible remains to be determined."

Non-Hodgkin lymphoma has also been on the rise worldwide, and it has been suggested that increasing ultraviolet (UV) radiation and sun exposure may be partly responsible. To investigate this hypothesis, Karin Ekström Smedby, of the Karolinska Institute in Stockholm, and colleagues conducted a population-based, case–control study in Denmark and Sweden in which they obtained detailed information on history of UV exposure and other risk factors for lymphoma from more than 3,000 lymphoma patients and a similar number of control subjects.

They found that increased exposure to UV radiation through sunbathing and sunburns was associated with a decrease, rather than an increase, in the risk of non-Hodgkin lymphoma. Increased UV exposure was also associated, although more weakly, with a decreased risk of Hodgkin lymphoma.

"[These] results suggest an inverse association between UV light exposure and non-Hodgkin lymphoma risk," Smedby and colleagues write. "However, before this association can be considered causal we need further confirmatory data from other epidemiologic studies and, ideally, a better understanding of possible biologic mechanisms," including UV-induced systemic immune modulation and the photo-initiation of vitamin D production.

In an editorial, William J. Blot, Ph.D., of the International Epidemiology Institute in Rockville, Md., and colleagues discuss how the results of these two studies provide new evidence that sunlight may have a beneficial influence on both cancer incidence and outcome and hypothesize that vitamin D may be a critical mediator in the relationship between sunlight and cancer. "In view of the major potential public health consequence of these results, further studies of sunlight and the vitamin D connection to cancer are certainly warranted," they conclude.

###

#

Citations:# Article: Berwick M, Armstrong BK, Ben-Porat L, Fine J, Kricker A, Eberle C, et al. Sun Exposure and Mortality From Melanoma. J Natl Cancer Inst 2005;97:195–99.# Article: Smedby KE, Hjalgrim H, Melbye M, Torrång A, Rostgaard K, Munksgaard L, et al. Ultraviolet Radiation Exposure and Risk of Malignant Lymphomas. J Natl Cancer Inst 2005;97:199–209.# Editorial: Egan KM, Sosman JA, Blot WJ. Sunlight and Reduced Risk of Cancer: Is The Real Story Vitamin D? J Natl Cancer Inst 2005;97:161–63.

Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage. Visit the Journal online at http://jncicancerspectrum.oupjournals.org/.


Story Source:

The above story is based on materials provided by Journal Of The National Cancer Institute. Note: Materials may be edited for content and length.


Cite This Page:

Journal Of The National Cancer Institute. "Two Studies Find Evidence That Sunlight May Have Beneficial Influence On Cancer." ScienceDaily. ScienceDaily, 8 February 2005. <www.sciencedaily.com/releases/2005/02/050205130639.htm>.
Journal Of The National Cancer Institute. (2005, February 8). Two Studies Find Evidence That Sunlight May Have Beneficial Influence On Cancer. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2005/02/050205130639.htm
Journal Of The National Cancer Institute. "Two Studies Find Evidence That Sunlight May Have Beneficial Influence On Cancer." ScienceDaily. www.sciencedaily.com/releases/2005/02/050205130639.htm (accessed August 20, 2014).

Share This




More Health & Medicine News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) — A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Raw: World's Oldest Man Lives in Japan

Raw: World's Oldest Man Lives in Japan

AP (Aug. 20, 2014) — A 111-year-old Japanese was certified as the world's oldest man by Guinness World Records on Wednesday. Sakari Momoi, a native of Fukushima in northern Japan, was given a certificate at a hospital in Tokyo. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Do More Wedding Guests Make A Happier Marriage?

Do More Wedding Guests Make A Happier Marriage?

Newsy (Aug. 20, 2014) — A new study found couples who had at least 150 guests at their weddings were more likely to report being happy in their marriages. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) — Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins