Does this mean I can't keep staying up until 3am?

From today's CNN, an article on a research study that says working nights is a big risk factor for breast (and prostate) cancer. Yikes. My typical schedule is to work at my computer until 1am (on an early night) to 4am (on a late night), and then get up around 11. In the winter, I am definitely restricting my exposure to sunlight--on weekends I might sleep in until noon or later.

The article seems quite specific to nighttime work, but the principles identified should apply to me, even if I'm not in a workplace per se. I'll be checking out the original study and will let y'all know!