Breast cancer remains the most common cancer in American women, excluding cancers of the skin, and accounts for 29% of all female cancer in the United States. The lifetime risk of an American women being diagnosed with breast cancer is 1 in 8. The American Cancer Society (ACS) estimates that in 2016 there will be 232,340 cases of invasive breast carcinoma and an additional 64,640 cases of in situ disease.1 In addition, 39,620 deaths are estimated to occur in 2016. Everyone knows someone who has been affected by breast cancer, and breast cancer advocacy remains strong in the public eye. Consequently, breast cancer screening has become highly politicized in the United States. Heated debates regarding the efficacy of mammographic screening for breast cancer have become a frequent lay media occurrence.
With a documented 34% decrease in breast cancer mortality since 1990, lung cancer has surpassed breast cancer in terms of mortality. The relative contribution of mammographic screening versus the improvement in adjuvant treatment remains controversial. Breast cancer screening has evolved from early screening trials in the 1960s to the early 1980s with film screen mammography; some studies used single view and interval screening every 2 to 3 years. Current standard mammographic screening includes two-view mammographic imaging with more than 93% performed with digital technology on dedicated mammography units, with specialty trained radiologists and technologist, and medical physicist closely overseeing the quality assurance and quality control of the operational mammographic units.
In 1992 congress enacted a law that went into effect in 1994 and ensured that women had access to quality screening mammograms. The U.S. Food and Drug Administration (FDA) developed and administered the Mammography Quality Standard Act (MQSA) regulations. As of November 1, 2016 there were 8698 certified facilities and 13,053 accredited units that meet a minimum baseline quality standard and are certified to legally operate in the United States and the total annual mammographic procedures reported up to November 1, 2016 were 38,541,887.2
Knowledge of the limitations of mammographic screening continues to drive development and investigations of new technologies. Some recent developments such as digital breast tomosynthesis (DBT) are quickly becoming mainstream. Preliminary data suggests that DBT will address some of the limitations of traditional mammography such as imaging the women with dense breast tissue and decreasing recall rates which are mostly due to overlap of tissue on mammography. As new technologies become available, physicians will continue to collect data and make screening recommendations hopefully not based on public opinion but on data.
In 1968, the World Health Organization published the landmark manuscript on screening for disease.3 The basic principles for screening a population are summarized in Table 67-1. Breast cancer meets most of the requirements for screening since the disease is common and important, there is an asymptomatic period during which the detection of the disease can be ...