Breast cancer is a lethal disease that occurs in 1 in 7 women. Deaths from breast cancer have fallen to the lowest levels in 50 years, although the overall # of cases has risen due to early screening and detection. When dealing with cancer, you want to avoid people dying unnecessarily by performing screening tests (in this case, mammography). When patients are faced with a diagnosis from a screening test, they are usually going to opt for treatment. Screening saves over 1000 lives per year. Unfortunately, we cannot predict which cancer will go on to develop into a more dangerous and life-threatening cancer and which won’t. It would be very difficult to say “no, let’s go ahead and just watch that” to a woman with a suspicious lesion on her mammogram.
Many researchers and clinicians still think the benefits of screening mammography outweigh the risks. Doubts raised by the authors of these studies that question mammography in 40-50 year olds and over 70 year olds are still too weak shake many experts’ belief in breast screening. Women cannot take the risk of not being diagnosed and treated and screening is a major way for this to happen. One of the troubles with any screening program is that it turns up people whom the disease would run a benign course…you overdiagnose in some instances and therefore overtreat that person. As it is not possible to distinguish between lethal and “harmless” cancers on an imaging study, all detected cancers are treated. Overdiagnosis and overtreatment are therefore inevitable. As the author of the JAMA study said, more studies will be needed to distinguish between slow growing and very aggressive tumors. But for now, if a woman wants to reduce her odds of dying of breast cancer (by at least 24%), then the current screening regimen should be followed. Besides just a cookie cutter approach to every female going to get an x-ray of the breast, public education campaigns should also be reinforced to teach women how to assess their own risk including not having kids till late in life, dense breast tissue, family history of breast cancer, genetic testing for BRCA gene, aging, taking female hormones for menopause symptoms, etc. This should be addressed on a case by case basis between an individual and her health care provider, and women should be made aware of the risks of possible overtreatment and overdiagnosis, radiation exposure, and limitations of screening mammography in picking up some quickly growing breast cancers that can be deadly. MRI can also be useful in picking up some lesions and later stage cancers that mammography may miss.
I also have a personal interest in this topic as my mom’s life was saved by a screening mammogram. One year she had a normal study and the next year she had a breast cancer that was picked up on the yearly mammogram. It had already spread microscopically to her lymph node, meaning it was an aggressive tumor and if she had just skipped a year or blown off that year’s mammogram, she would have missed picking up the cancer and it would have likely spread beyond the breast and been metastatic by then which is often lethal. It should be noted she was in her late 60’s at the time of her diagnosis, which means she falls in the 50-70 year old category that studies have demonstrated a clear benefit of yearly screening mammography. So it’s hard to imagine backing down on mammograms in the absence of more sophisticated screening measures when you have a personal story like this one that make you so thankful for screening studies; many people besides myself have these stories since so many women are affected by breast cancer.