Sun, 27 Jul 2008 07:10:41 BST CiteULike: Author Mirick http://www.citeulike.org/author/Mirick CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/randyt/article/582451 <i>Cancer Causes and Control, Vol. 17, No. 4. (May 2006), pp. 539-545.</i> Circadian Disruption, Shift Work and the Risk of Cancer: A Summary of the Evidence and Studies in Seattle Scott Davis Dana Mirick doi:10.1007/s10552-005-9010-9 Cancer Causes and Control, Vol. 17, No. 4. (May 2006), pp. 539-545. 2006-04-12T04:08:22-00:00 2006 Cancer Causes and Control 0957-5243 17 4 539 545 Springer melatonin http://www.citeulike.org/user/annathomson/article/2204265 <i>J. Natl. Cancer Inst., Vol. 93, No. 20. (17 October 2001), pp. 1557-1562.</i><br /><br />Background: Exposure to light at night may increase the risk of breast cancer by suppressing the normal nocturnal production of melatonin by the pineal gland, which, in turn, could increase the release of estrogen by the ovaries. This study investigated whether such exposure is associated with an increased risk of breast cancer in women. Methods: Case patients (n = 813), aged 20-74 years, were diagnosed from November 1992 through March 1995; control subjects (n = 793) were identified by random-digit dialing and were frequency matched according to 5-year age groups. An in-person interview was used to gather information on sleep habits and bedroom lighting environment in the 10 years before diagnosis and lifetime occupational history. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by use of conditional logistic regression, with adjustment for other potential risk factors. Results: Breast cancer risk was increased among subjects who frequently did not sleep during the period of the night when melatonin levels are typically at their highest (OR = 1.14 for each night per week; 95% CI = 1.01 to 1.28). Risk did not increase with interrupted sleep accompanied by turning on a light. There was an indication of increased risk among subjects with the brightest bedrooms. Graveyard shiftwork was associated with increased breast cancer risk (OR = 1.6; 95% CI = 1.0 to 2.5), with a trend of increased risk with increasing years and with more hours per week of graveyard shiftwork (P = .02, Wald chi-squared test). Conclusion: The results of this study provide evidence that indicators of exposure to light at night may be associated with the risk of developing breast cancer. 10.1093/jnci/93.20.1557 Night Shift Work, Light at Night, and Risk of Breast Cancer Scott Davis Dana Mirick Richard Stevens doi:10.1093/jnci/93.20.1557 J. Natl. Cancer Inst., Vol. 93, No. 20. (17 October 2001), pp. 1557-1562. 2008-01-07T15:50:48-00:00 2001 J. Natl. Cancer Inst. 93 20 1557 1562 breast cancer light night risk shift-work