Exposure to dim light at night hastens human breast cancer tumor cells' growth

The growth of human breast cancer tumors implanted in rats speeded up by 2.5 times when they were exposed to dim light at night according to a study conducted by Steven Hill and his team at Tulane University School of Medicine. They also found that the exposed rats’ cancer cells became resistant to the drug tamoxifen, which could be due to the suppression of melatonin production in the presence of light. The administration of melatonin, however, negated this effect. Hill now plans to validate these findings in human patients. Moreover, with his team, he is testing how dim light exposure affects prostate cancer.    

Read more in The Scientist.

R.T. Dauchy et al., “Circadian and melatonin disruption by exposure to light at night drive intrinsic resistance to tamoxifen therapy in breast cancer,” Cancer Research, doi:10.1158/0008-5472.CAN-13-3156, 2014