Educated guesswork I believe.
Not sure how 'real' this is likely to be in humans, I worked shift work for 2 years when I was in the US, it was 9 years ago. I had my first case of breast cancer 2 years ago and then again this year. If the mice were developing this type of cancer after 50 weeks of having their clocks put out by 12 hours a week, that would mean my 2 year stint on shift would have taken 7 years to develop but that doesn't explain the recurrence this year as I haven't worked any shifts. I don't have the gene so that's not an explanation.
The latest theory is that weight is a factor in breast cancer, which is why I'm working on mine, but at the same time, I weigh just over half the amount I did in the US, so since my weight is vastly reduced from then, there doesn't seem to be an explanation. I guess it's just chalking it up to 'one of those things'
_________________The Official "Saucy Minx"

This above all: To Thine Own Self Be True
"Red sky at night, Shepherds Delight"..Which is a bit like Shepherds Pie, but with whipped topping instead of mashed potato.