[Assessment of Brazilian clinical guidelines in oncology: gaps in drafting, applicability, and editorial independence].

The expansion in the variety of clinical guidelines in oncology is perceptible worldwide, highlighting the need to guarantee the quality of these documents. The study thus aimed to assess the quality of Brazilian national guidelines for treatments of breast, prostate, and colon and rectal cancers. We selected 12 Brazilian guidelines published by four different drafting groups (Ministry of Health, Supplementary Health System, and medical societies and associations), and the AGREE II instrument was applied. In all these guidelines, we identified important weaknesses in more than one Domain, especially low values for "applicability" and "editorial independence". The patterns observed per Domains are more related to the drafting group than the respective clinical conditions. Lower scores in "drafting rigor" and "editorial independence" were obtained by nongovernmental drafting groups, including absence of information or lack of its transparency. Although the "clarity of presentation" in the Ministry of Health guidelines was relatively lower, all the guidelines presented major limitations in "applicability". Consequently, in the overall assessment, none of the guidelines was recommended without modifications, and four were not recommended at all. Finally, it is necessary to upgrade the guidelines according to the underlying evidence ("methodological rigor") and to present the recommended practices in a comprehensible and applicable way ("applicability"), and to mitigate conflicting interests in order to offer cancer patients the best available care in Brazil.