We know the importance of early detection when it comes to treating cancer, but how does overdiagnosis impact this? A recent study completed in Denmark showed that as many as one-third of women there diagnosed with breast cancer had slow-growing tumors that didn’t need immediate treatment or had a cancer that was not malignant. As studies like this continue to fuel the discussion over when and how often women should be getting mammograms, as well as how accurate they are, Baptist oncologist Dr. Lindi VanderWalde shared her thoughts on how women need to think about mammograms.
Can you explain a bit more about what this study concluded?
The concern that’s been raised with this recent Denmark study is that mammograms might be too accurate. They compared two groups of women – one that had been invited to get mammograms and one group of women that lived in areas where there was no routine screening. Then they compared diagnosis rates. What they found was, not surprisingly, that women who lived in the areas that were invited to have screenings did have more detection of smaller tumors and non-invasive tumors.
Editorials take it a step further, saying there has been overdiagnosis. Some number of women in the non-screened group probably have something small happening in their breast that was never detected. What the study didn’t look at, though, was mortality and survival. I think in the end, that’s what each one of us is concerned about. The reason we do these mammograms is to improve survival. There have been other studies where they compare the results and have been able to demonstrate a mortality benefit. Women have improved survival in groups of women who are invited to a mammogram screening.
How does this study impact the way women should be thinking about mammograms?
Women should always remember – what is the purpose of a screening? The reason we do screenings for many diseases, not just breast cancer, is that a screening should pick up a disease process when it is still undetectable and improve the prognosis and care. Mammograms still follow these principles. The Denmark study illustrated the idea that mammograms will find small masses at earlier stages. If we find things at early stages, we’re going to improve survival. I would still advocate for a screening mammogram.
Is overdiagnosis a serious concern?
We certainly know that there is overdiagnosis in mammography. There are many more favorable breast cancers – hormone positive, early stage, noninvasive – that may never progress to the point where they will threaten a woman’s life. While that cancer might not be a life-threatening thing, there will always be a balance. How aggressively do we want to go after early precancers? Do you wait for them to become symptomatic? Having that screening mammogram is what I would recommend for my patients. It’s a test like any other test, there are limitations, good and bad things about it. Every woman should be having a discussion with their own personal physician about it and what benefits it will have for them. If something is identified, they will need to have the discussion about how aggressively they want to treat it. If they find an early cancer, very few women choose to avoid treatment. Usually, treatment is begun once it is detected.
What advice do you have for women in the Mid-South when it comes to mammograms?
In the end, some tumors are aggressive – biology makes them more aggressive in progression no matter when they are discovered. There are ongoing studies and investigation on how to identify people who have something in their mammogram that is not a life-threatening cancer, but we’re not there yet. Right now, I want to emphasize that women should come to their annual mammogram. Again, have that discussion with your physician about how often you should attend.