Beyond mammograms: Improving breast cancer screening
Over the past century, the personal response to breast cancer has dramatically changed. While breast cancer is still greatly feared (and rightly so), the increased visibility of breast cancer survivors has reduced the stigma that was once associated with the disease. High profile women, such as Guiliana Rancic, openly discussing life after their diagnosis with breast cancer provide a face for this cancer and motivate other women to look after their own health through preventive screening.
Screening aims to diagnose breast cancer before symptoms occur, while the cancer is in its early stage and, thus, easier to treat. Mammography and breast self-exam (BSE) have been the standard screening methods for decades. Unfortunately, controversy remains around the effectiveness of these methods. BSE has been encouraged for women starting in their early 20s, but research suggests that breast cancer death rates are not lowered in women who regularly perform BSE.
Mammography has been shown to save lives, but has come under recent fire for its limitations in diagnosis. Specifically, this test tends to over-diagnose individuals, which leads to invasive, unnecessary testing and anxiety. Of course, when it comes to cancer, many feel its better to be safe than sorry.
These limitations have resulted in calls for alternative methods to improve diagnosis. Particularly, including breast ultrasound or MRI with mammography increases the chances of finding cancer. While increasing the chances of diagnosing and subsequently treating cancer will improve survivability, adding ultrasound does not appear to improve the false positive rates that have been one of the major criticisms of mammography. However, it does appear promising in improving diagnosis, particularly in women with dense breast tissue and other risk factors. Hence, these improved diagnostic measures will help some but not all women.
Recently, a lot of media attention has focused on a promising new blood test for breast cancer. This test does not test for breast cancer per se, but can detect women with a high, genetic risk of developing breast cancer, years before breast cancer develops. Understanding risk early could result in preventative lifestyle changes.
Of course, genetic risk assessment is not perfect. Our increased understanding of human genes has raised much hope for the notion of personalized medicine and early disease detection and prevention. As we learn more about the gene-to-disease pathway, it is clear that this process is extremely complex. This complexity means that for many individuals, genetic testing might not provide a clear picture of their true disease risk. This can also be seen in the development of the genetic testing for the BRCA1 and BRCA2 genes, which have been linked to breast cancer. One of the chief issues with this type of testing is that it can cause undue psychological stress -- a positive test only means that the individual has an increased risk of getting breast cancer not that they will get breast cancer, but can still be scary and life-changing. Despite these risks, some women feel empowered to know their genetic fate and feel comfortable taking extreme preventive measures, including preventive mastectomies. The new blood test includes multiple genetic markers associated with breast cancer, so it may at least improve the accuracy of risk assessment.
Many view events like Susan G Komen's Race for the Cure and the pink ribbon as a sign of hope about our chances of curing breast cancer. While these social movements are important, the first step to a cure is early diagnosis. New methods in MRI and ultrasound appear promising in their ability to increase cancer detection in high-risk individuals. Additionally, a new blood test will improve our understanding of risk for breast cancer years before symptoms develop and could lead to individuals making lifestyle changes that reduce their own personal risk. Continued research into diagnostic measures is essential as proper diagnosis is the first step to curing this disease.