Diretrizes para detecção precoce do câncer de mama no Brasil. I - Métodos de elaboração

Abstract

Clinical guidelines are traditionally drafted by expert consensus. The benefits of mammographic screening have been questioned in recent years, owing to biases detected in the clinical trials that popularized its widespread use. Meanwhile, growing body of evidence on harms associated with mammographic screening also required a new approach, taking into account the uncertainties on the benefits and a balance between the gains and possible harms from screening. This article discusses the development of the new guidelines for early detection of breast cancer in Brazil, with details on the drafting methods and implications for the new recommendations. The new methodology features systematic literature reviews, assessment of the validity of the evidence, and the balance between each intervention's risks and benefits, ensuring greater transparency, reproducibility, and validity in the drafting process. The new guidelines also include recommendations for cases with suspicious signs and symptoms. The authors provide a detailed discussion of the advantages of the approach as compared to the traditional expert consensus model, as well as the methods' limitations and disadvantages. They also address the implications of various decisions, such as choices on study designs, screening effectiveness outcomes, definition of overdiagnosis, and methods for calculation.

Diretrizes para detecção precoce do câncer de mama no Brasil. II - Novas recomendações nacionais, principais evidências e controvérsias

“…The detailed methods for definition of the scope, research questions, search strategies, selection of studies, evaluation of the quality of evidence, and formulation of recommendations in the guidelines have been published elsewhere 8,9 .…”

“…The recommendations do not refer to the population at high risk of developing breast cancer. For early diagnosis we evaluated strategies of awareness of suspicious signs and symptoms for breast cancer, clinical criteria for identifying suspected cases in primary health care and the diagnostic confirmation in a single health care unit 9 .…”

“…Meanwhile, the most serious harm from screening is overdiagnosis and overtreatment, i.e., unnecessary diagnoses and treatments 9 . After 25 years of follow-up of Canadian clinical trials, 50% of the cases of non-palpable invasive cancer, detected by screening mammography alone, were classified as overdiagnosis 20 .…”

“…All five selected systematic reviews on screening with clinical breast examination concluded that there is still no evidence on this intervention's efficacy for the reduction of breast cancer mortality 12,22,23,24 . Randomized clinical trials in Kerala 25 and Mumbai 26 in India and a trial in the Philippines 27 reported that screening with clinical breast examination resulted in diagnosis of disease in stages with better prognosis 25 , which however could be attributed to lenght bias, overdiagnosis, or even a possible effect from the simultaneous application of a breast awareness strategy in the intervention group 9 . Evidence shows that screening with clinical breast examination is associated with a higher standardized breast cancer incidence rate 25 , which could indicate some degree of overdiagnosis.…”

“…The new guidelines for early detection of breast cancer in Brazil were based on systematic literature reviews of the risks and possible benefits of various early detection strategies 8,9 . The current article's objective is to present the new guidelines and a summary of the evidence for the recommendations, discussing the main controversies in light of the best and most current available evidence.…”