Cancer screening is arguably one of the more hotly debated procedures in medicine today. However, we we get emotional about cancer screening is when we lose touch with the benefit vs harm balance. Recent changes in mammography recommendations have clearly crossed this line.
It all seemed to start with the USPSTF guidelines in 2009 to not screen women in their 40s for breast cancer using mammography. There was an uproar, an a virtual thumbing up of noses to the recommendations by the American Cancer Society and various radiological societies. This seemed to feed on the uneducated populace that the USPSTF recommendations were purely driven by an attempt to ration care and save money.
But when emotions come into play, it seems to favor the benefits of screening. Early detection is key to breast cancer treatment and has been drilled into our heads to the point that few women would even consider waiting until they are 50 for their first mammogram.
But to make a fully informed decision, we need to understand all the facts. Does early detection of mammography save lives? Yes. Is this balanced out by the harms that is causes? The evidence does not suggest so. Why is screening by mammography to prevent breast cancer deaths a clear cut thing? There are a variety of reasons:
- A large percentage (57%) of breast lumps are identified by self exam. The patient then goes to their doctor and a mammogram is ordered. Later, the mammogram is credited with finding the breast cancer. Obviously not the case. This tends to overinflate the benefits of mammography.
- The rate of false negatives is also high, leading to lowered quality of life and extreme stress levels.
- Up to 22% of the cancers found on mammography may resolve on their own. In other words, we are treating something that will go away on its own. Again, if the mass is going to go away on its own, treatment had nothing to do with the outcome and yet the mammography is again credited with a life saved.
- When mammography is done, the risk of invasive surgery such as a mastectomy goes up. In Norway, this number went up a whopping 70%, but there was no improvement in breast cancer outcomes.
Women will generally pipe up and state that they want mammography to find that cancer early. Everyone seems to think that they’ll be in the group aided by mammography. But, statistically this is not true. Your risk of being harmed by a mammography, most notably in those younger than 50, is much greater than the risk of your life being saved.
This particular study looked at the details from Norway in more detail and found that mammography led to overdiagnosis in 15-25% of women in whom cancer was found on testing. These are women who would have had procedures done that did not need to be done. The costs and harms associated with this are staggering.
The bottom line is that, as I’ve always said, we cannot rely on early detection to “prevent” breast cancer (or any other cancer, for that matter). We must live a lifestyle that is anti-cancer and truly prevent breast cancer. In this scenario, early detection becomes superfluous.