Despite the dissemination of computer-based "clinical practice guidelines" as decision support systems, low practical compliance rates are still observed. The reason commonly invoked is that such recommendations, suited to average patients, are not rules for all the patients. Rather than providing automatic decision support, OncoDoc allows the clinician to operationalize the implemented breast cancer therapeutic expertise through his hypertextual reading of the knowledge base. In this way, he has the opportunity to interpret the information provided in the context of his patient therefore controlling his categorization to the closest appropriate "average patient". After a four-month real-life experimentation of the system, a survey was conducted among the users. The observed compliance, significantly higher than the best figures found in the literature, and the clinicians objective and subjective evaluation of the system reinforced the implementation choices adopted in OncoDoc.