Researchers shed new light on cancer risks associated with night work

Night work can increase cancer risk in men, according to a new study published in the American Journal of Epidemiology by a research team from Centre INRS–Institut Armand-Frappier and Centre de recherche du Centre hospitalier de l'Université de Montréal. The study is one of the first in the world to provide evidence among men of a possible association between night work and the risk of prostate, colon, lung, bladder, rectal, and pancreatic cancer and non-Hodgkin's lymphoma.

"Exposure to light at night can lead to a reduced production of the sleep , inducing physiological changes that may provoke the development of tumours. This hormone, habitually released in the middle of the night in response to absence of light, plays a pivotal role in hormonal functions and in the immune system", explained Professor Marie-Élise Parent of Centre INRS–Institut Armand-Frappier, the study's lead investigator.

Despite finding that night work increases the risk of a number of cancers, the researchers are intrigued by the absence of a relationship between duration of night work and found in the study. In theory, an increasing duration in the period of night work would be expected to be accompanied by an increase in the risk of cancer, but the results obtained did not confirm such a tendency. As well as opening up new research avenues, this finding raises questions about the factors that might influence people`s adaptation to night work. Other more targeted research, including Dr. Parent's current research on , will also allow for a more detailed study of the consequences of night work on health.

For this research, Dr. Parent and her team analyzed data from a study on and cancer that was conducted between 1970 and 1985, involving 3,137 men aged 35 to 70 years who had been diagnosed with a cancer at 18 hospitals in the Montreal metropolitan area, compared to a control group of 512 cancer-free individuals from the general population.

The epidemiological study by Marie-Élise Parent, Mariam El-Zein, and Marie-Claude Rousseau of Centre INRS–Institut Armand-Frappier and Javier Pintos and Jack Siemiatycki of Centre de recherche du Centre hospitalier de l'Université de Montréal and Université de Montréal was funded by Health Canada, the National Cancer Institute of Canada , Quebec's Institut de recherche Robert-Sauvé en santé et sécurité au travail, and Fonds de recherche du Québec - Santé (FRQS).

More information: The article is available at aje.oxfordjournals.org/content… /aje.kws318.abstract

add to favorites email to friend print save as pdf

Related Stories

Ovary removal may increase lung cancer risk

Jul 21, 2009

Women who have premature menopause because of medical interventions are at an increased risk of developing lung cancer, according to a new study published in the International Journal of Cancer. The startling link was ma ...

Heavy drinkers face significantly increased cancer risk

Aug 03, 2009

(PhysOrg.com) -- Heavy drinkers of beer and spirits face a much higher risk of developing cancer than the population at large, says a group of Montreal epidemiologists and cancer researchers. Their findings ...

Early treatment is key to combating hepatitis C virus

Aug 08, 2008

Canadian researchers have shown that patients who receive early treatment for Hepatitis C virus (HCV) within the first months following an infection, develop a rapid poly-functional immune response against HCV similar to ...

Recommended for you

Same cancer, different time zone

12 hours ago

Just as no two people possess the same genetic makeup, a recent study has shown that no two single tumor cells in breast cancer patients have an identical genome.

Brazilian researchers identify RNA that regulates cell death

16 hours ago

Researchers from the University of São Paulo (USP) have identified an RNA known as INXS that, although containing no instructions for the production of a protein, modulates the action of an important gene in the process ...

User comments