There have been several articles on the subject of cancer published over the course of the last week.  I’ve already written about the benefits of lifestyle in preventing cancer.  I think two others deserve discussion as well.

The first has to do with the link between sleep and exercise in cancer prevention.  Researchers at the National Cancer Institute studied the exercise and sleep patterns of nearly 6000 women and found that those who were physically active had a lower risk of developing breast cancer — but only if they regularly got at least 7 hours of sleep per night.  By contrast, those women who slept less than seven hours each night were at greater risk of the disease.  This is relevant to me because I tend to sleep poorly, and have been making an effort to improve my sleep habits.  There is also an expanding field of study, with researchers attempting to understand how cancer risk and sleep habits may be linked.  It is well known that hormone levels are dramatically affected by sleep patterns, so the line of study is definitely worth pursuing.

The second article relates to the possible spontaneous healing of cancer.  To quote the study’s authors,

It appears that some breast cancers detected by repeated mammographic screening would not persist to be detectable by a single mammogram at the end of 6 years. This raises the possibility that the natural course of some screen-detected invasive breast cancers is to spontaneously regress.”

If you’re considering not having your mammogram, I would suggest you read the full study here, and then read the National Cancer Institute fact sheet.  Naturally this has raised a number of questions.  Current recommendations are for women older than 40 to have a mammogram every 1-2 years.  The study was conducted in Norway, where authors split a group of women into two study groups.  The control group received one mammogram at the end of a six year period.  The study group received a mammogram every two years for six years.  Researchers found that the women who received regular mammograms had a higher rate of breast cancer, and from that concluded that the control group must have had some cancers that healed spontaneously.  There are several assumptions made in that conclusion, which may or may not be correct.  However, the idea of watchful waiting has already been widely accepted as a viable treatment option for prostate cancer.  I’m certain this study will inspire more concrete work that may lead to that option being viable for breast cancer as well.  Who knows?