Prior to the release last month of the Canadian National Breast Screening Study results, and despite a long line of studies by others that cast doubt, the average American still would have told you that when it comes to breast cancer, early detection is key. No one talked about the harms from screening nor did anyone explain what benefit really existed. The message was, "Just go get your mammogram!"
Now, everyone is not so sure.
And let's be clear, the debate is not about diagnostic mammograms once symptoms appear. The real debate is around screening mammography, in other words, for healthy women who have no symptoms and have not discovered any lumps.
What is a woman to do?
First, recognize that this study is good news. It gives women much more information about harms and benefits and helps them make more informed decisions. Then, let's talk about what NOT to do: Do not dig out the old shower cards and videos with step-by-step instructions on monthly breast self exam! That focused, determined, monthly search for cancer. The highest level of evidence -- the gold standard prospective randomized clinical trial -- proved that regimented breast self exam did more harm than good. That trial looked at more than 200,000 women, and found that the women who did monthly self exams did not find breast cancer earlier than the women who just went about their daily routines. But the BSE group found many more benign lumps than the control group, undergoing unnecessary biopsies at a much higher rate.
It is not intuitive, but it actually does make sense. If you feel something, do something. But don't go on a search for cancer because if you do, you will always find something. Anything. Everything.
Moving to mammography screening, the latest results reinforce that there has been some return on our investment in science and in raising awareness about the facts of breast cancer. In February, the Canadian National Breast Screening Study joined a growing body of evidence showing that mammography does not significantly reduce breast cancer mortality, and comes with a risk of overdiagnosis and overtreatment. We invest money in research and in education so things can change for the better. Since the initial mammography screening clinical trials were launched and reported, there have been new treatments for breast cancer and more women are aware that if they feel a lump while in the shower, putting on a shirt, or however, they should have it checked out. There have been at least eight large trials of mammography screening, all but one started between 1963 and 1982. What have we learned? Overall, at best mammography screening has a modest effect on breast cancer mortality. When analyzed in absolute terms, the death rate is reduced by just .05 percent. And each year, despite whatever progress has been made, and how many screening programs are instituted, 40,000 women and 430 men die from breast cancer in the United States (ACS 2014).
Those statistics are troubling and do not even capture the harm from screening. In the United States, that risk of harm has been estimated to be 22 percent to 30 percent.
We know that a significant proportion of breast cancers will never spread to other parts of the body. That means that women with cancer that would have never spread are becoming cancer patients unnecessarily -- undergoing surgery, chemotherapy and radiation -- and enduring the sometimes life threatening side effects that come with them. Whenever study results are released that point out the limitations of mammography and its harms, public outrage ensues. Much of this is fueled by the media giving a platform to trade associations for mammographers and to groups and individuals who have built their careers on mammography and the early detection mantra. Much less often heard is the voice of the true expert, the scientists who actually conduct and analyze the research that underlies medical interventions. It is boring, I suppose, to hear about mortality rates, long-term harms from screening, morbidity. Much more compelling is the sensational anecdotal voice of the woman who claims that a mammogram saved her life. We should be a society that believes in, understands and supports science. We should want what is best for women and we should take the time to figure out what that is beyond the sound bites and outrage.
So, what are women to do? Despite decades of fundraising, research and effort we still do not have a better answer to that question other than, be aware of breast cancer and generally what your risk is. And if you feel something odd, see a doctor. If you have no symptoms and look at the risks and benefits of mammography screening and decide to go ahead and have one, that is your decision. And if you decide not to, you are not a bad person.
All of the scientific evidence points to that strategy being more effective than a ritual search for cancer through breast self examination and mandatory annual mammography. It is time to move forward, for women's sake.
That is why NBCC launched Breast Cancer Deadline 2020. Our goal is to know how to end breast cancer by January 1, 2020. And we are taking a new and innovative approach. We are focusing on prevention, not detection.
NBCC is working with researchers and patient advocates on the Artemis Project for a preventive vaccine and the Artemis Project on the causes and prevention of metastasis. We know the only way to truly end this disease is to make sure no one gets it in the first place and to prevent metastasis so that no one dies from it.
In the meantime, mammography will still not prevent women from getting breast cancer or prevent many of them from dying from the disease. And we are left with the question: Is 40,000 deaths a year in the United States and 522,000 around the world really the best we can do? (GloboCan2012) The National Breast Cancer Coalition doesn't think so.