Mammography turns 40 this year. It was in 1973 that the American Cancer Society and The National Cancer Institute jointly launched the Breast Cancer Detection Demonstration Project. This was a nation-wide screening program involving 280, 000 healthy women between the ages of thirty-five and seventy-four who were invited to undergo annual breast cancer screening with mammography and physical examination. It was the first time most Americans had ever heard of mammography and it marked the beginning of our national effort to eradicate breast cancer through early detection. As the beleaguered test hits the “Big 4-0”, it finds itself in the throes of an all-out midlife crisis; its relevance questioned, its impact unclear, its future uncertain.
As the beleaguered test hits the “Big 4-0”, it finds itself in the throes of an all-out midlife crisis; its relevance questioned, its impact unclear, its future uncertain.
It was very different at the start. In 1973, mammography was surrounded by an aura of unbridled hope and optimism. After all, it was a mere twenty years earlier that the American Cancer Society had played a major role in the nation-wide implementation of another screening test. The Pap smear proved well accepted by the public and highly successful in reducing cervical cancer death rates. This experience would later inform the organization’s approach to mammography. The mammogram, it was hoped, would be breast cancer’s Pap smear. It was a dream, however, that would not be realized. Cervical cancer screening’s largely tranquil history stands in stark contrast to the controversy and acrimony that have so characterized mammography’s American journey.
It is notable that mammography has never been a particularly controversial test in other developed countries. This bifurcated history can be traced to two crucial early decisions made by mammography’s backers. The first concerns the appropriate age demographic for screening. In Europe and other developed countries with active screening programs, the test is generally accepted to be most appropriate for postmenopausal women. In such places, it is recommended for women starting at age fifty. In the United States, mammography’s primary proponents, the American College of Radiology and the American Cancer Society, adopted a position that women under fifty should be screened with mammography as far back as the 1970s. At that time, there was absolutely no scientific evidence that mammography benefitted these younger women. Rather than evidence, this decision was based on hope; hope that someday the desired evidence would be uncovered. This one question: whether women younger than fifty should be screened, has dogged mammography incessantly, residing at the heart of almost every major eruption of mammography controversy since its inception. It has been mammography’s dispute that will not die.
The second, and more consequential, decision made by mammography’s proponents, regards the manner in which the test would be presented to the public. Throughout its history, mammography has been promoted using simple, one-sided messages; a “just do it” approach that presents only the potential benefits with no mention of possible harms or limitations. This course, designed to minimize confusion and maximize compliance, has been successful in achieving high rates of mammography utilization. It has contributed nothing to true public/consumer education.
Routine screening with mammography reduces a woman’s likelihood of dying of breast cancer. This is true for women in their forties, fifties, sixties and possibly beyond. The magnitude of this benefit, however, increases with age. Thus, older women derive a greater degree of risk reduction than younger women. At the same time, mammography is associated with certain potential harms. Chief among these are false positive readings, where the mammogram shows a suspicious finding requiring further imaging or biopsy, only to be proven to be non-cancerous; false negatives, where breast cancer is missed, often due to dense breast tissue; and overdiagnosis, a scenario where a cancer that would not have otherwise come to light in the woman’s lifetime, is detected. While estimates vary, up to a third of mammography-detected cancers may fall in this category. Thus, paradoxically, while mammography may decrease a woman’s likelihood of dying of breast cancer, it increases her chances of being diagnosed with the disease. Some of mammography’s harms, for example false positive readings, are more common among women in their forties. In this way, screening involves a harm/benefit calculus; one that becomes more favorable to screening as women age.
Despite its failings, mammography is, and for the foreseeable future, will continue to be, an important component of women’s healthcare. The test has undoubtedly played a role in the documented decline in breast cancer mortality rates over the past twenty years. Furthermore, first-dollar insurance coverage is mandated under the Affordable Care Act, guaranteeing barrier-free access. However, as the test enters its fifth decade, it is time to abandon the paternalistic “just do it” approach to mammography promotion in favor of true informed decision-making; a fresh paradigm where women are given all the facts about mammography: its benefits and potential harms, and are empowered to make their own choices. Modern women deserve no less.