Read this book! Seriously, read this book. Buy it, or borrow it from the library and then send they author H. Gilbert Welch some money.
The full title of this book is: Should I Be Tested For Cancer? Maybe Not and Here's Why. A totally fascinating, important exploration of the benefits and drawbacks of cancer screening.
Back in November, there was a huge brouhaha when the US Preventative Services Task Force recommended that women between 40 and 50 not have routine screening mammograms. And people who were outraged about this kept saying on the radio that screening mammograms cut your risk of dying from breast cancer by one-third. This book explains the science behind that claim (and more). It turns out, with no screening mammograms, 3 women in a 1000 will die of breast cancer between 40 and 50. With screening mammograms, 2 in 1000 will dies. So, yes, screening mammograms cut the risk of dying from breast cancer by one-third. But that difference happens for 1 in 1000 women. And in exchange for that, 1000 women have to have 10 mammograms, half of them will have a positive screening mammogram at some point in the ten years, a large portion of those will have further invasive testing, some will be treated for cancer that would never otherwise have caused them symptoms, and some will have significant complications from the cancer treatment (maybe even including death). And it's not clear you actually reduce the overall death rate. If 1 in 1000 women doesn't die of breast cancer, but the overall death rate remains the same, have you actually done anything useful?
The benefits of cancer screening are far more modest than we have been led to believe, and the risks of screening are not minor. But various groups benefit from cancer screening (doctors are never sued for suggesting a screening; radiologists are thrilled that mammograms are recommended for half the population for half their lives; hospitals get to look like they're doing something for the community, while at the same time promoting their services).
I will question far more thoroughly future cancer screening suggested by my doctor. Starting with the freaking Pap smear for cervical cancer. I learned that once you've had 2 or 3 normal Pap smears and are over age 30, the recommendation is to get a Pap smear every 3 years. So why have I been getting a Pap smear every year? What is up with that? Who wants to get a Pap smear every year if there is no benefit?
While I'm here, check out the US Preventive Services Task Force website.
And read this totally compelling rant by Barbara Ehrenreich, about how mammography and breast cancer awareness has supplanted feminism, providing a way for institutions and people to signal that they care about "women's issues", without actually having to do anything useful.
Should I Be Tested For Cancer? Maybe Not and Here's Why
H. Gilbert Welch
2004
Available from Amazon
