Deliberation and decision are commonly considered to be joint processes in rational action, as in legitimate collegial decision-making in medicine. In oncology, this relationship is reflected in the institutionalization of multidisciplinary consultation meetings (Réunions de concertation pluridisciplinaires RCP) as a tool for medical decision-making. However, in a context of strong standardization of treatment, typical of evidence-based medicine, to what extent can RCPs be considered as a place for debate and decision-making? Based on observations of RCPs from various ethnographic fieldwork, this article shows that the conformity of decisions to recommendations and their collegiality can vary greatly depending on the context. The persistence of a form of clinical autonomy on the part of practitioners makes deliberation and decision appear to be reticulated and distributed processes that allow RCPs to be invested with varying uses and functions.