LAUSR

In three articles published in this issue, Migowski et al. introduce the new national guidelines for breast cancer control in Brazil 1,2,3. This update is timely as it addresses long-held misconceptions, recent controversies, and new developments. The authors should be commended for having formulated these guidelines on the basis of an independent, transparent, and methodologically sound review of the published scientific evidence. Breast cancer is a potentially curable disease if diagnosed and treated early. There are two different, but rather complementary, approaches to achieving this: (i) downstaging, i.e. by ensuring clinically detectable disease is diagnosed at an early stage and (ii) screening, i.e. through early detection of clinically occult disease, that is, before it causes symptoms or can be felt in a clinical examination (i.e. when tumor size is < 2cm). Much of the updated national guidelines focuses on screening. Mammography is far from a perfect screening tool, being associated with benefits as well as harms (e.g. falsepositives, overdiagnosis and overtreatment, and radiation-induced cancers). Nevertheless, the review of the published evidence by Migowski et al. confirmed that, despite recent controversies, the overall scientific evidence is consistent with mammographic screening reducing mortality from breast cancer by 20-25% among women invited to attend organized screening programs every two years between 50 and 69 years of age, with the benefits outweighing potential harms. These findings are in line with those from the International Agency for Research on Cancer (IARC) Working Group on breast cancer screening 4. Mammographic screening programs have been established in many high-income countries (HICs) since the late 1980s, when findings from the earliest randomized trials were published. Since then there has been increasing pressure from national and international advocacy groups for healthcare systems in low/middle-income countries (LMICs) to emulate HICs. Such demand is, however, ill-judged because what works in HICs does not necessarily work in LMICs. Organized mammographic screening programs are complex, multidisciplinary undertakings which, to be effective, require access to high-quality mammography, high coverage of the target population (at least 70% 5) with a call-recall system, timely access of women with screen-detected suspicious abnormalities to appropriate diagnostic and treatment services, as well as comprehensive built-in quality assurance mechanisms (e.g. trained healthcare workforce, standardized protocols, well-defined performance targets, Breast cancer control policies in Brazil: where to go from here?