Mammograms are universally accepted as the most effective way of screening for breast cancer; however, is this really true? Many women may be surprised to learn that there is more than one method for detecting potentially life-threatening masses in the breasts, and these varying procedures are being used in an increasing number of women in the population.  This is not to say that mammograms are not important or valuable as a detection tool in screening for breast cancers – however, in many cases it may not be effective when used alone, and as new screening technologies are developed and become more widespread an increasing number of women will need to work with their doctors to develop a more personalized approach to breast screenings.

According to a new report in the June issue of the American Journal of Medicine, for many years, mammography has been the sole imaging test recommended for breast cancer screening, and remains the only test proven to reduce breast cancer-related mortality. However, the widespread application of mammography in population-based screening remains controversial, owing to decreased sensitivity in women with dense breast tissue, radiation concerns, and a high rate of false-positive studies, leading to excessive breast biopsies.  Those who image the breasts are adapting to these challenges with the development of new technologies. Low-dose mammography can reduce radiation risk to the breast. Contrast-enhanced mammography can evaluate blood flow in the breast, similar to MRI. Tomosynthesis produces multiple mammographic slices through the breast, similar to computerized tomography (CT scan), and has significant potential to lower recall rates and increase specificity.

The article goes on to say that both whole-breast ultrasound and MRI have been shown to detect additional cancers in certain high-risk populations and will likely be increasingly used in screening women with dense breasts. MRI studies are very expensive and have a high false positive rate, i.e., they have difficulty in identifying a negative on the image as a true negative (without disease) in the patient.  However, a decrease in mortality has not been proven using these modalities.  Molecular imaging in the form of BSGI and PEM of the breast is widely available. Positron emission mammography (PEM) and breast-specific gamma imaging (BSGI) use molecular imaging to increase specificity in cancer detection by demonstrating increased metabolic activity.  However,  due to relatively large whole-body radiation doses (equivalent to 20-30 mammograms), they are not currently suitable for annual screening.

The reason that the same method will not work with every woman is because every woman’s body is different. Variations in the structure of a woman’s breast, the density of her breast tissue, or even the existence of implants may affect the ability of the standard mammogram to fully detect any underlying lumps or irregularities in her breast tissue. Simply put, every woman’s breasts are different, and so too must the screening for every woman be different.

While these advances are encouraging, it is improbable that any of the new technologies will replace mammography for population-based screening programs, because all have significant limitations.  Furthermore, given the heterogeneity of the human population, a “perfect” imaging technology for breast cancer screening will likely never be found.  However, women who feel as if they have different needs should consult with their doctor and ask whether or not there may be special considerations they should make as a part of screening for cancers. However, ultimately the main thing that older women should do is to continue receiving their mammograms regularly as well as younger women (less than 35 years of age) conducting breast self-examinations on a regular basis within the comfort of their own home. In coming years it is likely that the plan of action for women will begin to change depending on individual women’s needs, but the existence of different technologies is still no substitute for the screening methods that are commonly accepted and readily available.

– Yvonne S. Thornton, M. D., M. P. H.